Recent Advances in the Use of Botanical Extracts from Jatropha Species for the Sustainable Control of Insect Pests: A Systematic Review and Meta-Analysis

Abstract

The use of botanical extracts derived from Jatropha spp. offers a sustainable alternative for controlling insect pests, thereby reducing reliance on synthetic chemical insecticides. A systematic review and meta-analysis were conducted to summarize the published evidence on the insecticidal activity of these extracts. Electronic database searches were conducted to identify relevant studies evaluating Jatropha spp. botanical extracts against insect pests, including mortality, antifeedant activity, time of development, oviposition inhibition, and repellency. A random-effects meta-analysis for continuous variables with 95% confidence intervals was employed to compare treated insects against a control group. The study encompassed 77 articles, which evaluated extracts from various botanical parts of Jatropha curcas and Jatropha gossypifolia against insects from nine taxonomic orders. The results of the meta-analyses demonstrated that aqueous, ethanolic, and methanolic extracts from leaves and seeds were effective in increasing the mortality rate of treated insects. These extracts also affected the insects by prolonging development time, reducing weight gain in larvae and pupae, inhibiting oviposition, and increasing the percentage of repellency. Consequently, the foliar application of botanical extracts obtained from the leaves and seeds of J. curcas and J. gossypifolia represent a sustainable and agroecological alternative for the control of insect pests from different taxonomic orders.

1. Introduction

Insect pests can pose a threat to the global agricultural system, resulting in annual losses that reach up to 40% of global crop yield, causing economic costs amounting to $220 billion (https://www.fao.org/plant-health-day/es, accessed on 27 October 2025). To address this issue, farmers have intensively use synthetic chemical insecticides, which offer rapid and effective protection against insect pests [1]. Nevertheless, the indiscriminate use of these substances has resulted in significant ecological and toxicological consequences [2]. Consequently, the utilization of botanical extracts has emerged as a promising alternative for the sustainable management of insect pests, thereby reducing dependence on chemical insecticides [3]. Furthermore, the accessibility of botanical extracts is expected to be both affordable and convenient, and their rapid biodegradability is anticipated to be environmentally friendly [4].

Botanical extracts contain active compounds that are effective against a wide range of agricultural pests, offering a functional and ecological alternative to the use of synthetic insecticides [5]. The constituents present in plant extracts have been demonstrated to function as repellents, attractants, feeding deterrents, and growth inhibitors, thus impacting diverse physiological processes in insect pests [6]. In this context, members of the genus Jatropha (family Euphorbiaceae) have exhibited bioinsecticidal potential [7]. This genus comprises approximately 170 species of drought-tolerant shrubs and trees adapted to low-fertility soils. A previous systematic review has compiled evidence on the efficacy of extracts obtained from different parts of Jatropha curcas, which represents the most frequently used species [8]. The summary of the available evidence showed that methanolic, aqueous, petroleum ether, and essential oil extracts from both seeds and leaves have significant effects, as evidenced by the documented inhibition of development, oviposition, and adult emergence, along with an increase in mortality rates among a variety of insect pest species [8].

To date, no meta-analysis has been conducted to estimate the pooled effect of independent studies that assess botanical extracts from Jatropha, which is necessary to determine their efficacy against insect pests of important crops. Similarly, the available evidence concerning other species of the Jatropha genus [9,10] has not been analyzed. Therefore, the present study was conducted to address the following questions:

(1)

What is the insecticidal effect of the botanical extracts of Jatropha spp. on controlling insect pests?

(2)

What effect do the botanical extracts of Jatropha spp. have on the growth and development of larvae and pupae?

(3)

Which botanical extracts of Jatropha spp. are most effective at controlling insect pests?

(4)

Which insect pests are the botanical extracts of Jatropha spp. more effective against?

The present study aims to expand our knowledge on the effect of Jatropha botanical extracts, incorporating statistical meta-analysis tools, as well as published evidence on other species of the Jatropha genus that have demonstrated insecticidal activity against various species of insect pests. The results of this study will enhance our understanding of the bioinsecticide potential of this plant genus and its subsequent incorporation into sustainable integrated pest management strategies.

2. Materials and Methods

2.1. Protocol and Inclusion Criteria

The present study was conducted in accordance with an a priori protocol, which was developed following the PRISMA-P (Preferred Reporting Item for Systematic review and Meta-analysis Protocol) statement [11]. The protocol is available at the Open Science Framework website: (https://osf.io/q6fm8/overview?view_only=a414cfb04fcb4a23904b4e57ddab3b12, (accessed on 1 April 2026)).

The preparation and reporting of the study were performed in accordance with the Cochrane guidelines [12] and the updated PRISMA 2020 statement [13]. As outlined in

Table 1. Eligibility criteria based on the PICOS approach of the PRISMA statement.

Acronym	Definition
Population	We included studies that reported the effect of Jatropha spp. botanical extracts on insect pests of any taxonomic order affecting crops and vegetable products of agriculture and economic interest. Such crops may include one of several categories, including food crops (wheat, corn, rice, tomatoes, lettuce, legumes, potatoes), fruit crops (oranges, lemons, berries, mangoes, melons), fodder crops (barley, oats, sorghum, sugar beets, hay), timber crops, stored grain products, and oil crops
Intervention	We considered studies that reported feeding or contact bioassays of at least one botanical extract obtained from the from fresh or dried vegetative parts of Jatropha spp., including leaves, stems, roots, bark, seeds, and fruits. We considered the following four treatment categories: Botanical extracts, including hexane, acetonic, chloroform, ethyl acetate, petroleum ether, methanolic, and aqueous extracts Powders or macerates Botanical oils Secondary metabolites
Comparator	The selected studies should include at least one of the following categories as comparison groups: Studies that included a control group, which received no treatment or placebo, including any other inert substance, vehicle, solvent or water Studies comparing the effect of any other plant species (including powders, extracts, macerates, or oils), chemical insecticides, commercial botanical insecticides or any other substance against Jatropha spp. Studies that reported the use of two or more plant parts or fresh or dried parts of the plant, one of them will be used as a reference or control Studies that reported two or more doses, one of them will be used as a reference or control
Outcome	The studies should report any of the following outcomes, without prioritization: Insecticidal activity, defined as the percentage of mortality, including the number of insects or populations killed by the treatment, or the reduction in populations/colonies of pest insects with respect to a control group Effect on larval and pupal growth and development, defined as the anti-feeding effect, as evaluated by the reduction in larval and pupal weight. We also included any effect on fecundity and fertility, anti-oviposition effect, reduction in egg hatching, and any other physiological change were also considered
Studies	We included primary studies with experimental design that reported feeding or contact bioassays under laboratory, greenhouse, or experimental plot conditions. The studies should be published in English, Spanish, or Portuguese as full text in peer-reviewed journals. No temporal or regional restrictions were applied, and unpublished studies (gray literature) were not considered

, the PICOS approach was employed to select studies for inclusion in the systematic review and meta-analysis. In summary, the present study exclusively incorporated primary research articles with experimental design that were published as full text in peer-reviewed journals. These articles reported the insecticidal effect of Jatropha spp. botanical extracts against a range of insect pests that impact crops and vegetable products of economic importances.

2.2. Information Sources and Search Strategies

One reviewer (AVR) conducted a specialized search using the digital library system of the Metropolitan Autonomous University (https://bidi.uam.mx) to access the following electronic databases: Scopus, ScienceDirect, Web of Science, SciELO, CAB Direct, BioOne, PubMed, Virtual Health Library, and AGRIS. The searches were conducted from 29 August to 2 September 2023, with an update executed on 14 January 2026, to extend the search for additional relevant studies published between 2024 and 2025.

The search terms were defined as follows: “population” (Jatropha spp. OR Jatropha); “intervention” (extracts OR botanical OR hexanic OR acetonic OR methanolic OR aqueous); and “outcome” (insecticides OR insectistatic OR insect pest OR crop insect pest OR activity OR biocide). In each database, the available methodological filters were used to define the search process, with Boolean operators (AND and OR) being employed to extend the search command. A general search command was defined, with the searches being performed by title and abstract, when available, for example: Title-abs = (Jatropha) AND (extracts OR botanical OR hexanic OR acetonic OR methanolic OR aqueous) AND (insecticides OR crop insect pest). Supplementary Table S1 presents a comprehensive overview of the search strategy employed in the review, encompassing all databases that were included. Once the electronic searches were completed, all the bibliographic records were retrieved and downloaded as RIS/ENW file formats to construct an EndNote 21 (Clarivate; Philadelphia, PA, USA) library.

2.3. Study Selection Process, Information Collected, and Data Extraction

The selection process of the studies to be included in the narrative synthesis and the meta-analysis was conducted by a single reviewer (DD). The process began with the removal of the duplicates from the EndNote 21 library, which were removed manually and automatically using the duplicate find tool included in the software. The reviewer subsequently screened the records to identify relevant studies that met the inclusion criteria based on the title and abstract. Following this step, the selected records were retrieved in full text to assess their eligibility for final inclusion. To address this, the reviewer employed a standardized questionnaire based on the inclusion criteria outlined in Table 1. Before being used with the entire library, the questionnaire underwent a pilot testing phase, using a random selection of 10% of the screened studies to identify and rectify any inconsistencies and ensuring its reliability. A second reviewer (AFM) meticulously reviewed the selected studies to ensure that they fulfilled the defined inclusion criteria. In cases where inconsistencies were identified, the two reviewers reached a consensus.

For each selected study, the main characteristics were extracted by a single reviewer (RFB) and recorded in an Excel spreadsheet, with a codebook being generated for the correct management of the information. The database enabled the reviewer to generate summary tables and data charts. The following items were extracted: study identification (author, language, and year of publication), study design, main objective of the study, a brief description of the methodology, and a summary of the results reported. The data items also included the name of the Jatropha spp. evaluated, the type of botanical extract, and how it was used to control the insect pests. Furthermore, the type of sample evaluated (eggs, larvae, pupae, or adult insects) and the insecticide effect of the Jatropha spp. botanical extract were also extracted. Finally, also any information regarding the identification of secondary metabolites and their bioactivity in the control of insect pests was extracted for the summary of evidence. Once the extraction was completed, another reviewer (DD) confirmed and corrected the extracted information for all the selected studies.

2.4. Risk of Bias Assessment

The risk of bias was assessed by one reviewer (MARL) using an adapted version of a previously published methodology [8]. The evaluation of each study was conducted by assigning a binary designation “Yes” (meets the defined criterion and is considered free of bias) or “No” (does not meet the criterion and there is risk of bias in the criterion evaluated). The evaluation criteria employed are outlined as follows: (1) Adequate definition of the population included in the study, (2) Clear specification of the method employed in the bioassays, (3) Consistency of reporting, with no discrepancies, (4) Outcomes must include an assessment of the insecticidal activity or the effects of the botanical extracts on larval and pupal growth and development, (5) The description of the method for obtaining extracts and treatments must be clear, and they must be compared to a control or reference group, (6) Results must not be selectively reported. The results of the risk of bias assessment were presented both individually for each study and also as a percentage summary for the whole set of studies reviewed.

2.5. Statistical Analysis of the Bioactivity of Jatropha spp. Botanical Extracts

In order to assess the bioactivity of Jatropha spp. botanical extracts against insect pests, the following outcomes were estimated: (1) mortality, defined as the average percentage (±SD, standard deviation) of larvae, pupae, or adult insects killed by the treatment at any stage of development; (2) antifeedant activity, defined as the average (±SD) weight of larvae, pupae, or adults at a given day during any stage of development; (3) development time, defined as the average (±SD) number of days taken for a larva or pupa to complete their stage development; (4) oviposition inhibition, defined as the average number (±SD) of eggs laid by the treated insects; and (5) repellency activity, defined as the average percentage (±SD) of larvae, pupae, or adult individuals that stop feeding due to treatment exposure. In cases were a single publication reported the results for distinct Jatropha spp., botanical part, types of extracts, or insect species, each result was extracted and considered as an individual study for the meta-analysis.

All the outcomes were independently assessed through a meta-analysis for two-group comparison of continuous variables, employing the mean difference as the effect size. The model incorporated the sample size, the mean, and the standard deviation for the treatment and the control/reference groups, assuming unequal group variance. Given the anticipated heterogeneity across studies, the DerSimonian–Laird (D-L) random effects model was employed to generate the pooled estimates and 95% Confidence Intervals (95% CI) [14]. Moreover, complementary meta-analyses were constructed for each outcome, incorporating the Jatropha spp., the botanical structure, the type of extract, the insect species, and the stage of development, all of which were evaluated as methodological subgroups within the model.

As previously outlined [15], the z-test was utilized to ascertain a significant overall effect size, whereas the Cochran Q test of homogeneity was employed to assess heterogeneity among publications, following the recommended level of p = 0.1. The Tau² statistic was employed as a measure of heterogeneity, with values greater than 1 being considered indicative of substantial heterogeneity [14]. Finally, the I² statistic was employed to assess the proportion of variation in effect estimates attributable to heterogeneity in true effects rather than to sampling error [16].

2.6. Secondary Analysis and Software

It is acknowledged that the mortality percentage is an outcome which may be dependent on both the time of exposure and the extract concentration. Therefore, the effect of both variables was assessed by including them in methodological subgroups meta-analyses as categorical groups and as continuous moderators in univariate random effects meta-regression models. Prior to the analysis, all values of extract concentration were converted to ppm in order to standardise comparisons across the studies. For each variable, three ordinal categories were constructed: exposure time, short (1–2 days), moderate (3–5 days), and long (7–25 days); extract concentration, low (1000 to 10,000 ppm), medium (20,000 to 62,500 ppm), and high (>100,000 ppm). This approach enabled the determination of the association of both variables with the insecticidal activity of Jatropha spp. botanical extracts.

The heterogeneity of the studies was visually examined using Galbraith plots, which present a scatterplot of the z-score of the effect size on the y-axis plotted against the inverse standard error (precision) on the x-axis. A regression line that passes through the origin is fitted to represent the overall effect size with a parallel 95% CI region, with an additional reference line at y = 0 indicating “no effect” [14]. In the absence of heterogeneity, 95% of studies should be distributed across the region. Furthermore, as suggested for meta-analysis that include more than 12 studies, the publication bias was formally assessed using an Egger regression-based test to determine the presence of a small-study effect, defined as smaller studies reporting larger effect sizes [17]. The test performs a weighted linear regression on the effect sizes on their standard error, weighted by the precision, hypothesizing that there is a significant association between the effect sizes and the precision, with a zero-slope test confirming the small study effect.

Leave-one-out (sensitivity analysis) meta-analysis was conducted to identify possible studies in which exaggerated or distorted results may be present, while cumulative meta-analysis was used to identify trends in effect size, with the year of publication used as the ordering variable [15].

All the meta-analyses and secondary analyses, and graphs were performed in Stata 19 (StataCorp; College Station, TX, USA) using the “Meta-analysis tool” from the statistics menu. All additional graphs and maps were produced in Prism 11 (GraphPad Inc.; San Diego, CA, USA), DataWrapper 1.0 (https://www.datawrapper.de accessed on 10 December 2025) and SankeyMATIC 1.0 (https://sankeymatic.com accessed on 15 December 2025). In all cases, a value of p < 0.05 was considered significant.

2.7. Use of Artificial Intelligence

The application Rubriq Premium 1.0 from American Journal Experts (https://rubriq.com accessed on 5 January 2026) was used for translation of the original manuscript from Spanish to English, and DeepL Write Pro 26.3 (DeepL SE; Cologne, Germany) software was used to proofread and correct the English language.

3. Results

3.1. Selection of Studies

The comprehensive search in electronic databases yielded a total of 959 records, of which a substantial proportion was contributed by PubMed, Scopus, and CAB abstracts, accounting for 81.0% (777 records). In contrast, VHL, ScienceDirect, and SciELO had the lowest number of records with 13, 10, and 5 records, respectively. A total of 181 duplicates were eliminated, resulting in 778 records remaining for evaluation during the screening process. Following the application of the inclusion criteria to the title and abstract, 246 publications were selected that met the established inclusion criteria and were then retrieved in full text. Of these, 79 publications could not be located. After applying the eligibility format to the 167 full-text articles, 92 publications were excluded on the basis that they did not meet the inclusion criteria. The following reasons for exclusion were documented: 40.3% of the studies failed to include the defined outcomes, 22.5% did not present the population, 15.7% were not primary studies, 12.3% did not report the origin of the sample, and 10.1% were not the defined type of study. A detailed list of the excluded studies, accompanied by the primary reason for exclusion, is provided in Supplementary Table S2.

According to the PRISMA 2020 flow chart depicted in Figure 1, a total of 77 studies were included in the systematic review and meta-analysis, of which 70 studies included Jatropha curcas, 5 studies reported results for Jatropha gossypiifolia, and 2 other studies included Jatropha dopharica. The complete list of the 77 studies included is presented in Supplementary Table S3.

3.2. General Characteristics of the Studies

The systematic review and meta-analysis included 77 studies that were published between 2002 and 2025 (Appendix A). English was the predominant language in 92.2% (71/77) of the studies, followed by Portuguese and Spanish with three studies each. A total of 72.7% of the studies were published in countries from Africa and Asia (29 and 27, respectively), while the remaining 21 studies were conducted in countries from Latin America. All the publications included had an experimental design, being in vitro laboratory conditions the most frequent (82%, 65 studies), whereas the studies conducted under greenhouse and experimental plot conditions were less common (2 and 7 studies, respectively), with the remaining three studies assessing mixed conditions. With respect to the Jatropha spp. vegetal parts from which botanical extracts were obtained, 57% and 16.8% employed seeds or seed oil, respectively (38 and 13 studies). The leaves were employed in 24.6% (19/77) of the studies, while five studies employed at least two distinct vegetal parts, and the remaining two studies reported the use of stem bark.

Among the 77 studies that were included in the systematic review, maceration was identified as the most frequently reported extraction method (53 studies), followed by Soxhlet and mechanical extraction (13 and 6, respectively). In two studies, filtration and hydrodistillation were used as the primary extraction methods, while in another study, boiling was reported as the extraction technique. The primary extracts obtained across the studies were predominantly aqueous (36 studies), acetonic (8), petroleum ether (8), methanolic (5), powders (5), hexanic (4), ethanolic (3), and eight studies that reported a mixture of extracts. Regarding the taxonomic order of the insect pests examined in each study, Coleoptera (29 studies) and Lepidoptera (25) were the most frequent, followed by Hemiptera (6) and Isoptera (6). Other five studies reported the effects of botanical extract against a mixture of insect pests from different orders, while the remaining six studies included insect pests from the orders Homoptera, Thysanoptera, and Orthoptera.

3.3. Risk of Bias of Individual Studies

The results of the risk of bias assessment conducted on the 77 studies included in the narrative synthesis are depicted in Supplementary Figure S1. In total, 100% of the studies were qualified as having a low risk of bias because they reported the plant species and the taxonomic order of the insect pests. Furthermore, 92.2% of the studies had a low risk of bias because they provided comprehensive and detailed descriptions of the botanical extraction method, the treatments evaluated, and their respective control groups. In the presentation of the variables, 98.7% of the studies included in the narrative synthesis presented a clear evaluation of the insecticidal activity, as well as 90.9% of the studies showed a clear specification of the application method (bioassay of ingestion or contact) and therefore were rated as having low risk of bias. With respect to consistency of reporting (absence of discrepancies) and the selective reporting of results, 28.6% and 20.7% of the studies, respectively, were rated as having an unclear risk of bias in these criteria.

3.4. Summary of Results of the 77 Individual Studies Included in the Systematic Review

A synthesis of the principal outcomes reported in each of the 77 studies included in the systematic review is presented in Appendix B.1, Appendix B.2 and Appendix B.3, with the results for each Jatropha spp. categorized according to the botanical part and the type of extract.

3.5. Meta-Analyses of the Mortality

Supplementary Table S4 presents a summary of the sub-group meta-analyses conducted to estimate the mortality of insect pests due to Jatropha spp. botanical extracts, with the forest plots from each subgroup meta-analysis depicted in Supplementary Figure S2. The pooled estimate of 57 individual studies reported in 23 publications demonstrated a significant increase in mortality of 54.56% (95% CI: 47.56 to 61.55) in insects treated with botanical extracts compared to the control group (z = 15.30, p < 0.001). The homogeneity test revealed substantial heterogeneity among the studies (Q = 26,785.73, p < 0.001), a finding that was confirmed by I² (99.79%) and Tau² (692.39) statistics, whose values indicated the existence of considerable disparity.

An analysis of the effect by species revealed that Jatropha curcas extracts exhibited a significant increase in insect mortality of 54.15% (48.24 to 60.07) in comparison to the control group, whereas Jatropha gossypifolia extracts had a pooled overall mortality of 58.47% (19.26 to 97.67) in treated insects. No significant difference in efficacy was detected between the two species (Q_b = 0.05, p = 0.831), indicating that both species possess a comparable and high insecticidal effect.

With regard to the botanical part from which the extract was obtained, all the structures evaluated had a significant insecticidal effect, with the extracts derived from seeds having the highest efficacy, increasing mortality by 58.50%. Followed by extracts from the fruit (53.00%), stem/bark (48.45%), and leaves (47.88%). The test for differences between groups was not significant (Q_b = 1.88, p = 0.597), indicating that the insecticidal activity of Jatropha remains consistent across the various botanical parts that were examined. On the contrary, the type of extract used was a determining factor in the mortality of the treated insects, as suggested by the significant differences found between groups (Q_b = 559.26, p < 0.001). The most efficient extracts were found to be ethyl acetate (73.33%), hexanic (67.99%), acetonic (65.86%), and phorbol ester (63.34%). Aqueous extracts exhibited intermediate mortality, achieving 46.56%. In contrast, the lowest insecticidal activity was observed in petroleum ether and chloroform extracts (22.58% and 27.13%, respectively).

The meta-analysis encompassed a total of 16 insect pests, 12 of which were treated with extracts of J. curcas and 4 with J. gossypifolia (

Table 2. Summary of the D-L random-effects subgroup meta-analysis, which included 57 individual studies reported in 23 publications that assessed the effect of Jatropha spp. botanical extracts on the mortality of insect pests.

Jatropha spp.		Main Crop Affected	Mean Difference (95% CI) *	z (p Value) **	Q (p Value) ***	I2 (%)
	Insect Species
Jatropha curcas
Coptotermes vastator		Timber trees	79.54 (78.06 to 81.01)	105.89 (<0.001)	-	-
Zabrotes subfasciatus		Stored grains	67.41 (54.55 to 80.27)	10.28 (<0.001)	3.68 (=0.055)	72.84
Spodoptera frugiperda		Corn	66.48 (60.88 to 72.09)	23.25 (<0.001)	2944.54 (<0.001)	99.39
Nezara viridula		Soybean	66.36 (60.09 to 72.63)	20.76 (<0.001)	0.82 (=0.366)	0.00
Myzus persicae		Cabbage	58.09 (45.62 to 70.56)	9.13 (<0.001)	61.15 (<0.001)	91.82
Odontotermes obesus		Wheat, rice	58.06 (41.82 to 74.29)	7.01 (<0.001)	17.99 (<0.001)	88.88
Brevicoryne brassicae		Cabbage	53.70 (39.00 to 68.40)	7.16 (<0.001)	154.16 (<0.001)	97.41
Planococcus citri		Coffee	40.93 (29.50 to 52.36)	7.02 (<0.001)	8.33 (=0.080)	51.98
Spodoptera litura		Cabbage, asparagus	35.66 (33.43 to 37.88)	31.40 (<0.001)	-	-
Rhyzopertha dominica		Stored grains	29.22 (17.41 to 41.03)	4.85 (<0.001)	25.75 (<0.001)	92.23
Tribolium castaneum		Stored grains	27.38 (24.19 to 30.57)	16.82 (<0.001)	3.91 (=0.142)	48.86
Spilarctia obliqua		Sessame, mustard	21.16 (−0.72 to 43.05)	1.89 (=0.058)	191.96 (<0.001)	99.48
Sesamia nonagrioides		Sorghum	20.00 (−6.55 to 46.55)	1.48 (=0.140)	-	-
Rhynchophorus palmarum		Palm fruit	2.30 (0.61 to 3.98)	2.67 (<0.001)	-	-
Jatropha gossypifolia
Busseola fusca		Corn	70.63 (12.85 to 128.40)	2.40 (=0.017)	26.05 (<0.001)	96.16
Ostrinia nubilalis		Corn	70.00 (48.79 to 91.20)	6.47 (<0.001)	-	-

* Effect size = mean difference (Treatment—Control). ** Test for overall effect size (z = 6.82, p < 0.001). *** Test for difference between groups: Q_b = Chi² (d.f. = 15) = 4891.11, p < 0.001.

). Except for two cases, most insects pests exhibited increased mortality levels in response to the botanical extracts, which exerted a differential insecticidal activity. The top five species with the highest susceptibility were Coptotermes vastator (79.54%) (Isoptera: Rhinotermitidae), Busseola fusca (70.63%) (Lepidoptera: Noctuidae), Ostrinia nubilalis (70.00%) (Lepidoptera: Pyralidae), Zabrotes subfasciatus (67.41%) (Coleoptero: Chrysomelidae), Nezara viridula (66.36%) (Hemiptera: Pentatomidae), and Spodoptera frugiperda (66.48%) (Lepidoptera: Noctuidae). The species Myzus persicae (Homoptera: Aphidae), Odontotermes obesus (Blattodea: Termitidae), and Brevicoryne brassicae (Hemiptera: Aphidae) showed intermediate susceptibility, with mortality rates ranging from 53.70% to 58.09%. Finally, Jatropha spp. extracts exhibited low insecticidal activity against Rhyzopertha dominica (29.22%) (Coleoptera: Bostrichidae), Tribolium castaneum (27.38%) (Coleoptera: Tenebrionidae), Spilarctia obliqua (21.16%) (Lepidoptera: Noctuidae), Sesamia nonagrioides (20.00%) (Lepidotera: Noctuidae), and Rhynchophorus palmarum (2.30%) (Coleoptera: Curculionidae).

The secondary analyses for the mortality of insect pests are presented in Supplementary Figure S3.

When analysing the effect of the extracts according to exposure time, mortality estimates differed between groups, although the test for differences between groups did not reach statistical significance (p = 0.051). The highest insecticidal effect was observed in the long exposure group (7 to 25 days), where mortality increased by 63.34%, followed by the moderate exposure group (3 to 5 days) with a mortality of 51.11%, while the lowest effect (47.87%) was observed in the short exposure group (1 to 2 days). According to the bubble plot from the meta-regression, despite the positive trend between longer exposure times and higher insect mortality, the coefficient was not statistically significant (0.94, p = 0.057; Figure 2a). Mortality estimates differed significantly between concentration groups (p < 0.001), with the low concentration group (1000 to 10,000 ppm) showing the highest mortality (65.58%), followed by a comparable insecticidal effect of 47.03% and 50.37% for the medium and high concentration groups, respectively. Despite a negative trend was observed between the log of extract concentration and insect mortality, the coefficient of −8.06 was not statistically significant (p = 0.104, Figure 2b).

The Egger test indicated no evidence of publication bias, as the coefficient for the small study effect was not significant (β₁ = −0.14, p = 0.841). Furthermore, the Galbraith plot provided a visual confirmation of the substantial heterogeneity among the studies because there were several studies lying outside across the 95% CI region. The cumulative meta-analysis indicated that the direction of the effect (an increased mortality rate) was consistently established from the earliest publications from 2009, and as additional studies were incorporated, the effect size gradually stabilized. The sensitivity analysis demonstrated that the pooled estimate remained consistent within the overall confidence interval (47.66 to 61.55) after the iterative exclusion of each of the 57 individual studies. This finding indicates that no individual study had a disproportionate influence on the result.

3.6. Meta-Analyses of the Antifeedant Activity

As detailed in Supplementary Table S5, which presents the sub-group meta-analyses results, and Supplementary Figure S4, which presents the forest plots, the antifeedant activity was reported in seven publications that included 23 individual studies. All studies included in the meta-analysis evaluated J. curcas extracts obtained from seeds exclusively, avoiding the possibility of conducting comparisons between species or botanical parts. The pooled estimate demonstrated a significant reduction in weight gain of −20.50 mg (−29.80 to −11.20) in insects treated with botanical extracts in comparison to the control group (z = −4.32, p < 0.0001), thus indicating a notable antifeedant activity of Jatropha spp. extracts. The homogeneity test indicated substantial heterogeneity among the studies (Q = 4533.07, p < 0.001), with considerable disparity as evidenced by the 99.51% of I² and 485.21 of Tau².

As depicted in Figure 3, with the exception of oil, all the extracts exhibited a significant decrease in weight gain, characterized by variations in the magnitude of the effect. Hexanic extracts showed the greatest reduction in weight gain, with a mean difference of −28.93 mg. This was followed by acetonic and aqueous extracts, which showed moderate reductions of −17.83 and −15.98 mg, respectively. Conversely, methanolic extracts had the lowest, although significant, reduction of −11.87 mg. Despite this variation, the test for differences between groups was not statistically significant (Q_b = 4.53, p = 0.339), indicating that the antifeedant activity of J. curcas remains consistent across the various types of extract examined.

The meta-analysis included four insect species that exhibited a differential effect on weight gain in response to the botanical extracts (Q_b = 56.27, p < 0.001). The most susceptible species was S. obliqua, which showed a reduction in weight gain of −64.00 mg, followed by S. frugiperda with a moderate reduction of −22.39 mg. Finally, J. curcas extracts exhibited low antifeedant activity against Copitarsia decolora (−6.78 mg) (Lepidoptera: Noctuidae) and Spodoptera litura (−6.38 mg) (Lepidoptera: Noctuidae), whose reductions in weight gain were not statistically significant compared to the control group.

According to the results summary presented in Supplementary Figure S5, Egger’s regression test did not detect significant evidence of small study effects (β₁ = 2.07, p = 0.058). However, the Galbraith plot indicated substantial heterogeneity among the studies, as evidenced by the dispersion of points above and below the regression line and the confidence region. As demonstrated in the cumulative meta-analysis, except for two studies conducted at the beginning of the period, the estimates remained within the range of −25.5 to −8.40 mg throughout the entire period analyzed, thereby confirming the temporal consistency of the effect of J. curcas extracts on the weight gain of insect pests. This pattern suggests that the evidence accumulated to date is sufficiently stable and that the incorporation of future studies would have a limited impact on the direction and magnitude of the estimated effect. The findings of the sensitivity analysis indicated that the pooled estimate constantly persisted within the overall 95% CI of −29.80 to −11.20, indicating that the estimates are and not determined by any specific study.

3.7. Meta-Analyses of Development Time

Supplementary Table S6 presents a summary of the sub-group meta-analyses conducted to estimate the effect of Jatropha spp. botanical extracts on the development time of the insect pests, and Supplementary Figure S6 presents the forest plots of the meta-analysis. The pooled estimate from 30 individual studies included in 10 different publications demonstrated that in comparison to the control group, the insects treated with the botanical extracts from J. curcas showed a significant increase in their development time of 3.27 days (0.89 to 5.64; z = 2.70, p = 0.007). With a value of Q = 12,420.23, the homogeneity test indicated a significant heterogeneity among the studies (p < 0.001), a finding further confirmed by the I² (99.77%) and Tau² (43.03) heterogeneity statistics, whose values demonstrated the existence of substantial disparity. Given that all the studies evaluated exclusively J. curcas, it was not possible to conduct a comparison between species.

The meta-analysis indicated the differential activity of the extracts on the development time depending on both the insect species and the stage of development (

Table 3. Summary of the D-L random-effects subgroup meta-analysis which included 30 individual studies reported in 10 publications that assessed the effect of Jatropha spp. botanical extracts on the stage of development of the insect species.

Insect Species	Stage of Development	Mean Difference (95% CI) *	z (p Value) **	Q (p Value) ***	I2 (%)
Copitarsia decolora	Larval	5.54 (4.56 to 6.51)	11.12 (<0.001)	2.86 (=0.091)	65.00
Schistocerca gregaria	Nymphal	4.97 (3.82 to 6.12)	8.45 (<0.001)	0.64 (=0.425)	0.00
Spilarctia obliqua	Larval	0.89 (−1.78 to 3.58)	0.66 (=0.511)	–	–
	Pupal	2.67 (0.91 to 4.42)	2.99 (<0.003)	–	–
Spodoptera frugiperda	Larval	3.94 (−0.11 to 7.99)	1.91 (=0.057)	7766.24 (<0.0001)	99.86
	Pupal	2.57 (1.10 to 4.04)	3.43 (<0.001)	358.82 (<0.001)	97.49
Spodoptera litura	Larval	1.50 (−0.28 to 3.28)	1.65 (=0.099)	–	–
	Pupal	1.00 (−1.09 to 3.09)	0.94 (=0.350)	–	–

* Effect size = mean difference (Treatment—Control). ** Test for overall effect size (z = 2.70, p < 0.001). *** Test for difference between groups: Q_b = Chi² (d.f. = 4) = 33.18, p < 0.001.

). The greatest prolongation in development time was observed in the larval stage of Copitarsia decolora, which experienced a significant increase of 5.54 days, followed by the nymphal stage of Schistocerca gregaria (Orthoptera: Acrididae) that showed a significant increase of 4.97 days. S. frugiperda, exhibited a differential effect between developmental stages with evidence of high heterogeneity (>95%) indicating substantial variability among studies. The larval stage showed a marginal non-significant increase of 3.94 days (p = 0.057), while the pupal stage exhibited a significant but smaller prolongation of 2.57 days (p < 0.001). A similar pattern was observed in S. obliqua, where the larval stage was not significantly affected (0.89 days; p = 0.511), whereas the pupal stage showed a significant prolongation of 2.67 days (p = 0.003). This suggests that the insecticidal effect of Jatropha spp. extracts on development time may be more pronounced during the pupal stage in this species. Finally, S. litura was the least susceptible species to the extracts because neither the larval stage (1.50 days; p = 0.099) nor the pupal stage (1.00 days, p = 0.350) exhibited significant alterations in development time, indicating that this species is largely unaffected by Jatropha extracts.

According to the secondary analysis summarized in Supplementary Figure S7, there was no evidence of publication bias (β₁ = −0.79, p = 0.583), and the Galbraith plot suggested substantial heterogeneity across the individual studies, as the points were distributed mainly above the 95% confidence region. The cumulative meta-analysis revealed that although the direction of the effect size varied during the early years, the prolongation of development time consistently established from 2019, with the magnitude of the effect gradually stabilizing as additional studies were incorporated. Finally, the sensitivity analysis showed that the pooled estimate remained consistent after iterative exclusion of each of the 30 individual studies.

3.8. Meta-Analysis of the Oviposition Inhibition

Supplementary Table S7 presents a summary of the sub-group meta-analyses conducted to estimate the mortality of insect pests due to Jatropha spp. botanical extracts. Supplementary Figure S8 provides a visual representation of the forest plots from the meta-analysis. Eleven studies that were included in six publications showed that, in comparison to the control group, the pooled estimated from the treated insects had a significant reduction in oviposition of −20.53 eggs laid (−28.77 to −12.28; z =−4.88, p < 0.001). According to a value of Q = 23,789.02, the homogeneity test revealed substantial heterogeneity across the studies (p < 0.001), with the heterogeneity statistics I² (99.96%) and Tau² (184.31) confirming this disparity.

An analysis of the effect by Jatropha spp. revealed that J. curcas extracts exhibited a significant reduction in insect oviposition of −43.73 eggs laid (−60.74 to −26.73), while J. gossypifolia extracts showed a modest reduction of −3.60 eggs (−4.21 to −2.99) in treated insects. A significant difference in the efficacy of the two species was identified (Q_b = 21.36, p < 0.001), suggesting that J. curcas has a substantially greater oviposition-inhibiting effect than J. gossypifolia. Regarding the botanical part from which the extract was obtained, significant differences in oviposition inhibition were observed between the structures evaluated (Q_b = 5.65, p = 0.017). The seeds-derived extracts had the greatest efficacy, reducing oviposition by −46.90 egg laid, while in contrast, the extracts derived from the leaves did not demonstrate a significant effect on oviposition (−7.87%, p = 0.124).

The subgroup meta-analysis by type of extract revealed a differential effect on the oviposition of the treated insects (Q_b = 51.97, p < 0.001). Oil was identified as the most effective extract, achieving a reduction in oviposition of −46.90 eggs laid. This was followed by diethyl ether, ethanolic, and crude extracts, which showed intermediate but significant oviposition reduction, with a range of −10.85 to −2.75 eggs laid in comparison to the control (p < 0.001). In contrast, aqueous extracts had no significant effect on oviposition (−10.85, p = 0.201).

The meta-analysis included five insect species, among which Jatropha spp. extracts exerted differential oviposition inhibitory activity depending on the specific insect evaluated (Q_b = 2431.02, p < 0.001). The most susceptible species were C. maculatus (−58.74 eggs laid) and S. zeamais (−33.43 eggs laid), whereas C. chinensis showed moderate susceptibility, with a reduction in oviposition of −4.28. Finally, Jatropha spp. botanical extracts did not significantly inhibit the oviposition of S. gregaria or T. castaneum (p > 0.05). Due to the reduced number of studies included, no secondary analyses were conducted.

3.9. Meta-Analyses of the Repellency Activity

A summary of the sub-group meta-analyses conducted to estimate the repellency activity effect of Jatropha spp. extracts is presented in Supplementary Table S8, with their forest plots included in Supplementary Figure S9. All the studies included in the meta-analysis evaluated exclusively extracts of J. curcas. The pooled estimate of the eight individual studies reported in three publications showed a significant increase in repellency of 33.37% (21.29 to 45.46) among the insects treated with the botanical extracts compared to the control group (z = 5.41, p < 0.001). The homogeneity test revealed substantial heterogeneity among the studies (Q = 173.98, p < 0.001), a finding that was confirmed by the heterogeneity statistics I² (95.98%) and Tau² (272.58), whose values indicated the existence of considerable disparity.

There were significant differences in repellency activity depending on the botanical part from which the extract was obtained (Q_b = 11.83, p < 0.001). Seed extracts showed the highest efficacy, with an increase in repellency of 52.40% (33.46 to 71.35), while leaves-derived extracts also had a significant repellent effect, though to a lesser extent (17.05%, 9.11 to 24.99). Furthermore, the type of extract utilized was a determining factor in the repellent activity against the treated insects, as suggested by the significant differences found between the groups (Q_b = 32.61, p < 0.001). The most efficient extracts were petroleum ether (45.52%), and oil extracts (43.20%). Methanolic and chloroform extracts showed intermediate efficacy, with repellency values of 26.75% and 21.27%, respectively, with the lowest repellent activity being observed in hexanic extracts (7.59%).

The meta-analysis included a total of three insect pest species, among which the botanical extracts from J. curcas resulted in differential repellent activity on the evaluated species (Q_b = 15.77, p < 0.001). S. zeamais was the most susceptible species, with a repellency of 65.01%, followed by Rhynchophorus ferrugineus (43.20) (Coleoptera: Curculionidae) and T. castaneum (17.05%). Due to the reduced number of individual studies, no additional secondary analyses were performed.

4. Discussion

This systematic review and meta-analysis identified a total of 77 publications documenting the insecticidal activity and developmental effects of extracts obtained from different botanical parts of Jatropha spp. for the control of insect pests. The geographical distribution of these studies was concentrated in tropical regions, primarily in East Africa, South Asia, and Latin America. This finding can be attributed to the ecological adaptation of the genus Jatropha (Euphorbiaceae), which includes approximately 186 species (https://cir.nii.ac.jp/crid/1370285712611113216, accessed on 27 October 2025), and whose natural distribution is mainly restricted to tropical and subtropical areas. The lack of studies in regions such as Europe, North Asia, and North America may be attributed to climatic conditions that do not favor the growth and proliferation of these species, as well as to the limited presence of crops that are vulnerable to tropical insect pests. The predominance of research in Africa indicates a regional interest in the development of botanical alternatives for the management of insect pests, particularly those that affect stored grains and crops of economic importance. This approach responds to the need to reduce the use of synthetic insecticides, enhance food security, and promote sustainable agricultural practices.

With respect to the representativeness of Jatropha spp., the majority of studies have focused on J. curcas, followed by J. gossypifolia and, to a lesser extent, J. dopharica. These results are consistent with previous research that has demonstrated the bioactivity of extracts from the seeds, leaves, and oil of J. curcas against insects of various taxonomic orders [8], consolidating its potential as a phytosanitary resource in the context of pest management. In addition, the summary of evidence indicated that aqueous and powder extracts, primarily derived from leaves and seeds, exhibited insecticidal properties that included high mortality rates and disruptions in the development of insect pests. This finding is particularly relevant from an agroecological perspective, as these extracts can be produced in an accessible manner by local producers, without requiring complex or costly extraction processes. Consequently, the use of botanical extracts from Jatropha constitutes a viable and sustainable alternative for the control of insect pests, both within storage systems and in agricultural crops affected by polyphagous pests. The majority of publications in this study were in English, suggesting a potential barrier to the dissemination of knowledge from regions such as Africa and Latin America, where access to scientific literature in English may be limited. Consequently, the paucity of research on less extensively studied species of the Jatropha genus may be attributed to this phenomenon.

The findings of this study confirm that extracts from the leaves and seeds of J. curcas exhibit notable insecticidal activity and disrupt the development of insect pests associated with grain storage. These findings were also demonstrated in a previous study, which observed a significant increase in mortality and a reduction in insect populations, accompanied by physiological alterations, as well as a decrease in oviposition, inhibition of adult emergence, an increase in anti-feeding activity, and a high percentage of repellency [8]. The observed prolongation of larval and pupal development, in conjunction with the diminished oviposition, indicates a direct impact on the reproductive cycle of pests. This impact has the potential to result in a sustained population decline below the economic threshold, thus aiding in the prevention of substantial losses in crops and in the economy of producers in various regions. These effects would directly contribute to the protection of stored grains, including corn, wheat, rice, oats, cowpeas, beans, sorghum, barley, lentils, and chickpeas, and reinforce the potential of J. curcas as an agroecological alternative for post-harvest management of insect pests.

Although a numerical increase in mortality was observed with longer exposure times (from 47.87% at 1–2 days to 63.34% at 7–25 days), the test for differences between exposure time groups was not statistically significant. This finding suggest that the mortality data analyzed in the study does not provide statistical support to the hypothesis that there is a variation in mortality according to the duration of exposure, despite the numerical increase observed over time. However, the expected time-dependent effect of the Jatropha botanical extracts may be hindered by the high heterogeneity observed (I² > 90%). Furthermore, all exposure periods resulted in substantial and significant insecticidal activity, with comparable effects observed among the groups. This finding indicates that the insecticidal effect of Jatropha extracts is rapid and robust, achieving significant mortality even within the first 48 h of exposure. In conclusion, given that the exposure time was not identified as a significant continuous moderator, the observed differences between Jatropha spp., botanical parts, extracts, and insect spp. are not influenced by variations in exposure periods across the studies, thereby supporting the validity and reliability of those subgroups comparisons.

In contrast to exposure time, the extract concentration had a significant effect when analyzed categorically, but in a non-linear fashion. Surprisingly, the lowest concentration group (1000 to 10,000 ppm) produced the highest mortality, whereas medium and high concentrations resulted in lower insecticidal activity. This paradoxical finding may be explained by some biological mechanisms, including behavioral avoidance at high concentrations, where insects may detect and avoid treated surfaces or diets; feeding deterrence, where high doses reduce consumption before a lethal dose is ingested; phytotoxic effects that alter the palatability of the substrate; and hormetic responses, where low doses stimulate toxic or stress-related pathways more effectively than high doses. Nevertheless, the inclusion of extract concentration as a continuous moderator in the meta-regression lacked statistical significance. However, this finding does not invalidate the categorical results, instead it underscore the association between concentration and mortality is both non-linear and complex, suggesting that a simple linear model may not adequately capture the underlying biological dynamic of the botanical extracts from Jatropha spp. Taken together, these findings have important implications for the interpretation of the main subgroup analyses because they should be interpreted with caution, as they may be partially influenced by differences in the concentrations used across studies. However, the meta-regression and stratified subgroup analyses already accounts for this source of variation, strengthening the validity of the overall conclusions. Future studies on Jatropha-based botanical insecticides should report concentrations in standardized units (ppm) to facilitate cross-study comparisons and explore dose–response curves to identify optimal concentrations, thus avoiding unnecessarily high concentrations that may reduce efficacy through behavioral avoidance or feeding deterrence.

These findings reinforce the potential of J. curcas as an agroecological solution for managing insect pests affecting stored grains, including corn, wheat, rice, oats, cowpeas, beans, sorghum, barley, lentils, and chickpeas. Furthermore, the aqueous extract of J. curcas seeds has demonstrated efficacy against phytophagous insects, including Aphis gossypii, Cheilomenes spp., Dydercus spp., Nisotra spp., Podagrica spp., and Zonocerus variegatus, common pests in okra (Abelmoschus esculentus) crops in West Africa [18]. These results suggest that botanical extracts from J. curcas can be utilized in the cultivation of regionally important crops. However, it would be appropriate to expand their evaluation under different agroecological conditions and against endemic insect pests to validate their effectiveness in diverse regional contexts.

When extracted using suitable solvents and combined with appropriate adjuvants, the botanical extracts from Jatropha spp. acquire pesticidal properties that enhance their effectiveness in the field [19]. In addition, it was observed that extracts of J. curcas exhibited bioactivity against polyphagous lepidoptera of the Noctuidae family, including S. frugiperda, S. exigua, and H. armigera. These lepidopterans are notorious for their ability to damage a wide range of agricultural crops, including corn, sorghum, tomato, soybean, cabbage, tobacco, peanut, cotton, broccoli, cauliflower, lettuce, and spinach. The application of these extracts could contribute to the preservation of these crops, thereby reducing economic losses and enhancing food security. Moreover, Jatropha spp. botanical extracts could assist in decreasing the reliance on synthetic chemical insecticides, whose excessive use has had deleterious effects on the environment and human health [20].

Notably, seeds from local genotypes, such as J. curcas Atencingo, have been found to contain compounds such as oleic and linoleic acids, which have demonstrated bioactivity against S. frugiperda [21]. In this context, previous studies have associated these fatty acids with mechanisms of action that include the induction of apoptosis in neuronal cells of Helicoverpa zea [22] and transient uncoupling in SF-21 cells of S. frugiperda, affecting their respiratory metabolism [23]. The search for novel control strategies has prompted the investigations of synergies between extracts from different botanical species, as well as other organisms and microorganisms. For example, in comparison to the individual application, the combination of extracts from the leaves of Lantana camara and J. curcas has shown higher larval mortality and lower egg hatching in Diparopsis castanea, a cotton pest in Central Africa [24]. Similarly, a synergistic interaction has been demonstrated between the botanical extract of J. curcas and the enzymatic extract of Serratia marcescens in the control of S. frugiperda [25]. This finding provides a novel framework for the development of combined formulations that integrate lytic enzymes and plant metabolites, with the potential to improve their effectiveness of insect pest control. Furthermore, the utilization of mixtures with different mechanisms of action has the potential to diminish the probability of resistance development in insect pests populations, thus strengthening sustainable control strategies.

This study identified a limited amount of research reporting the bioinsecticidal activity of J. gossypifolia against insect pests. This scarcity of evidence for this species could be attributed to its nature as a regional shrub, predominantly distributed in southern Africa, where climatic conditions favor its growth [26]. However, the findings reveal that leaf extracts of J. gossypifolia exhibit insecticidal activity against S. exigua and S. frugiperda, which are two insect species that affect economically important crops such as broccoli and corn, respectively. Likewise, an effect was observed on the development of stored grain pests, including C. chinensis and T. castaneum. It is important to note that most of the studies documenting this activity have been conducted in countries such as Thailand, Bangladesh, and Colombia, suggesting that these species have been evaluated within specific local contexts. The evidence summarized suggests a growing interest in exploring alternative control measures that are derived from endemic plant resources and are adaptable to the agroecological characteristics of each region.

J. gossypifolia has been demonstrated to possess several mechanisms of action that contribute to the protection of local agricultural crops, thereby reinforcing its potential as an agroecological control agent. The use of plant species that possess bioactive properties, such as J. gossypifolia, constitutes a promising strategy for the management of insect pests, particularly within agricultural systems that aspire to reduce dependence on synthetic chemical insecticides and promote integrated management practices which are adapted to regional particularities. This phenomenon is corroborated by complementary studies conducted with other species belonging to the Euphorbiaceae family. For instance, aqueous extracts of Euphorbia thymifolia have shown notable feeding deterrent and repellent properties against Rhyzopertha dominica [27], while the latex of Euphorbia tirucalli has inhibited the oviposition of Callosobruchus maculatus [28]. These results demonstrate the value of exploring and applying plant extracts in the agroecological context for the control of insect pests. Earlier research has documented the insecticidal properties and the impact on the development of S. frugiperda when hexanic, methanolic, and ethyl acetate extracts obtained from Ricinus communis seeds were employed [28]. These findings serve to reinforce the notion that various species of Euphorbiaceae possess bioactive compounds with the potential to be incorporated into integrated pest management strategies, both in food crops and in stored grain systems.

Finally, methanolic and ethanolic extracts from J. dopharica leaves exhibited limited insecticidal activity, with effects observed solely against C. chinensis. The inclusion of only two studies in this systematic review and meta-analysis on J. dopharica precludes the generation of conclusive evidence to recommend its use as an alternative for insect pest control. The divergent outcomes and the paucity of studies may be attributable to the restricted geographical distribution and the limited accessibility in the field. Nonetheless, these preliminary results suggest that J. dopharica could have specific applications in the regional management of certain insect pests. This approach would facilitate a more precise estimation of its potential as a tool in sustainable control strategies.

5. Conclusions

The objective of our research was achieved by synthesizing the body of evidence for the different species, demonstrating a greater amount of research on J. curcas but with a well-documented effect, while J. gossypifolia and J. dopharica showed lower efficacy but promising results as sustainable alternatives in the integrated management of insect pests, both in agricultural crops and in storage systems. The accessibility of aqueous and powdered extracts, in conjunction with their established efficacy, renders them as promising alternatives for producers in tropical regions seeking sustainable and cost-effective solutions for insect pest management. However, in further research, it will be necessary to conduct toxicity tests and ascertain that they do not pose a threat to non-target insects and human health. Time of exposure did not have a significant effect on the insecticidal effect of Jatropha extracts, which supports the robustness of comparisons across species, plant parts, and extract types. Conversely, concentration demonstrated a non-linear impact, with low concentrations yielding surprisingly high mortality rates. These findings emphasize the significance of optimizing dosages and cautioning against the utilization of excessively elevated concentrations in the context of botanical insecticide applications. The results obtained confirmed the potential of the Jatropha spp. as a viable agroecological alternative for the biological control of insect pests belonging to different taxonomic orders. As suggested by Dalavayi Haritha et al. [5], the integration of botanical extracts from these species into organic farming systems, in conjunction with alternative integrated pest management strategies, holds promise as a highly effective approach. The implementation of such integration would allow producers to utilize these extracts as a preventive measure, thereby contributing to the mitigation of insect pests outbreaks that have the potential to compromise crop productivity.

6. Limitations

This study has several limitations that should be considered when interpreting the results. First, the studies included were published exclusively in English, Portuguese, and Spanish, which may have excluded relevant research available in other languages or in non-peer-reviewed journals, thus limiting the comprehensiveness of the analysis. Second, the studies employed a variety of methodologies and experimental designs, which complicates direct comparison between them and limits the possibility of generalizing the findings. Finally, substantial variability was observed in the content of active ingredients present in the different plant parts of Jatropha used, attributable to geographical differences. This variability represents a significant challenge for the standardization and production of extracts with a consistent chemical composition. In this regard, the present research constitutes a first effort to systematically synthesize the available information by employing robust statistical methodologies that facilitate the integration of results from studies with disparate approaches and experimental conditions. Despite the heterogeneity among the studies analyzed, it was possible to generate estimates of the insecticidal potential, as well as the effects on the development of insect pests, providing quantitative evidence of their bioactive potential. However, this heterogeneity must be carefully considered when interpreting the results, as it may influence the reproducibility and applicability of the recommendations in different agroecological contexts.

7. Perspectives

Further research is needed to identify and characterize a greater number of metabolites with bioinsecticidal activity present in Jatropha spp. extracts, with the aim of advancing toward their commercial-scale production, making them available to producers locally and globally. Consequently, it is recommended that bioassays be conducted under greenhouse and field conditions to evaluate the performance of these extracts in real-world scenarios and to determine the environmental and agronomic variables that may influence their effectiveness. These studies will contribute to the optimization of their formulation and application, thus strengthening their role as an agroecological alternative in pest control.