Search Results (73)

In the search for new alternatives for controlling parasitic agents, proteases from Beauveria bassiana stand out. The aim of this study was to evaluate in silico and in vitro the ovicidal potential of B. bassiana proteases on Eurytrema pancreaticum Janson, 1889 (Dicrocoeliidae) eggs. Beauveria bassiana Bals. -Criv., 1835 (Cordycipitaceae) (IP 361) was cultivated for enzymatic production. Proteins were precipitated with acetone (1:4 ratio), and specific activity was determined. Protease profiles were assessed via zymography, and inhibition by phenylmethylsulfonyl fluoride (PMSF) and ethylenediaminetetraacetic acid (EDTA) was tested. Three-dimensional models of the proteases were generated. Eurytrema pancreaticum eggs were used for the in vitro anthelmintic evaluation of the proteases. The results showed that precipitation significantly concentrated proteolytic activity (p < 0.01) compared to the crude extract. However, no chitinase activity was detected. The proteolytic profile of the precipitate revealed five bands with molecular weights from 25.6 to 66.9 kDa. In the in vitro tests, the proteases significantly (p < 0.01) reduced the number of intact E. pancreaticum eggs by 53% compared to the control with denatured enzymes. These findings highlight the ovicidal potential of B. bassiana proteases, though further studies are needed to confirm their application in parasite control. Full article

Cowpea, Vigna sp., is an important, low-cost protein source in subtropical and semi-arid regions, where seasonal rainfall makes storage necessary. However, the weevils Callosobruchus maculatus and C. chinensis cause significant grain losses during storage. While synthetic fumigants are commonly used to control these pests, their risks to mammals have prompted the search for safer alternatives. In this context, we tested palo santo, Bursera graveolens, essential oil with limonene, α-phellandrene, o-cymene and β-phellandrene, menthofuran, and germacrene-D as a sustainable approach. This plant is readily accessible, produces high fruit yields, and is used in households for various purposes. We evaluated the fumigant toxicity, repellency, and ovicidal effects of B. graveolens essential oil on both Callosobruchus species. Our results showed that B. graveolens oil was toxic to C. maculatus (LC₅₀ = 80.90 [76.91–85.10] µL) and C. chinensis (LC₅₀ = 63.9 [60.95–66.99] µL), with C. chinensis being more susceptible (SR = 1.27). Molecular docking analyses revealed that all the oil’s compounds bind to both the GABA and octopamine receptors, exhibiting high energy affinities; however, germacrene shows the strongest affinity in these receptors. C. chinensis was strongly repelled at all concentrations, while C. maculatus was repelled only at lethal concentrations. No ovicidal effect was observed in either species. In conclusion, our findings suggest that B. graveolens essential oil is a promising and sustainable protectant for stored cowpeas in small-scale storage units. Full article

The primary strategy for managing Nacobbus aberrans has traditionally relied on synthetic chemicals. However, increasing regulatory pressure on unsafe products has led to a growing research focus on nematicides. Despite this, chemical nematicides remain more effective than other control methods. Consequently, there is a pressing need to develop novel nematicides that are both effective and environmentally safer. This study aimed to evaluate the nematocidal efficacy of various synthetic molecules against the second-stage juveniles of N. aberrans, the false root-knot nematode. A total of fifty-eight synthetic derivatives were obtained and tested in vitro at a concentration of 500 µg/mL. The results identified the AGAz family as the most promising, with AGAz-3 (LC₅₀: 52.7 µg/mL) and AGAz-4 (LC₅₀: 103.22 µg/mL) surpassing the efficacy of chitosan. Our findings emphasize the strong potential of AGAz-3 and AGAz-4 as nematocidal agents, particularly for in situ applications in agricultural settings. Additionally, AGAz-3 demonstrates potential not only as a nematocidal agent but also as an incentive for related research exploring its analogs as effective ovicidal compounds and investigating its efficacy against other phytonematodes. Furthermore, compounds from the N-Sulfonyl-hydrazone and N-acyl-hydrazone series showed efficacy (>50%), warranting additional experiments to assess their effectiveness across the most important pest phytonematodes. Full article

Equine farming faces growing challenges with helminthoses, aggravated by the indiscriminate use of anthelmintics without technical criteria. This practice favors resistance to these drugs, generates residues in animal products, compromises food safety and human health, and, when excreted in large quantities, negatively impacts environmental health by affecting invertebrates and fecal microorganisms. This highlights the importance of the One Health approach. A promising alternative is biological control with nematophagous or helminthophagous fungi such as Duddingtonia flagrans, Pochonia chlamydosporia, Arthrobotrys oligospora, Monacrosporium thaumasium, Mucor circinelloides and Purpureocillium lilacinum. Due to their different mechanisms of action, ovicidal and predatory fungi, when used together, can act in a complementary and synergistic way in the biological control of helminths, increasing their effectiveness in reducing parasitic infections. The use of these fungi through biosynthesized nanoparticles from fungal filtrates is also emerging as a new approach to nematode control. It can be administered through feed supplementation in commercial formulations. The aim of this review is to explore the use of helminthophagous fungi in the control of helminthiases in horses, highlighting their potential as a biological alternative. It also aims to understand how these fungi can contribute effectively and sustainably to parasite management in horses. Full article

Plutella xylostella is the primary lepidopteran pest of Brassica crops due to its resistance to numerous insecticides. Multipesticide resistance in insects of agricultural importance is a global problem, and new methods of effective control that are less harmful to the environment are becoming increasingly necessary. The present study analyzed the effects of the aqueous extract of Simarouba sp. at concentrations of 10, 5, 1 and 0.1% in comparison with distilled water (as a control) on the feeding preference, oviposition, and embryonic development of P. xylostella. The results demonstrated that the aqueous extract of Simarouba sp. decreased oviposition and feeding in P. xylostella. A reduction in larval hatching was also observed, indicating ovicidal properties. In particular, the 1% concentration resulted in a more significant decrease in oviposition and the number of hatched larvae. Furthermore, concentrations of 10% and 5% caused food intake suppression, while concentrations of 1% and 0.1% reduced dietary intake by 97% and 78%, respectively. This study highlights the efficacy of Simarouba sp. aqueous extract in controlling the diamondback moth, as larval feeding and the number of individuals reaching the larval stage were reduced. Thus, the control method used in this laboratory study is expected to be successful if utilized on a large scale. Full article

Gastrointestinal nematode infections significantly impact small ruminant production, causing substantial economic losses worldwide. The rising resistance to anthelmintics has led to the search for alternative treatments, including phytotherapeutic approaches. This study investigates the chemical composition and anthelmintic activity of crude extracts and fractions from Simarouba berteroana, an endemic plant from Hispaniola, against a multidrug-resistant isolate of Haemonchus contortus. Chemical analyses revealed high contents of phenolic compounds, tannins, and flavonoids and confirmed the presence of 22 quassinoids, 5 phytosterol lipids, 3 terpenoid quinones, 3 alkaloids, and 1 naphthoquinone. The hydroalcoholic and iso-butanol fractions showed the strongest egg hatching inhibition (IC₅₀ = 0.93 and 1.21 mg/mL, respectively), while hexane fractions were less effective (p < 0.05). Fluorescence microscopy showed that the extracts and fractions adhered to eggshells, causing evisceration and cuticle detachment in hatched larvae. All extracts, except for hexane fractions, inhibited larval exsheathment at 0.3 mg/mL, with phenolic compounds being responsible for this effect. These results provide the first evidence of the ovicidal and larval exsheathment inhibition activities of S. berteroana extracts and fractions against H. contortus, highlighting their potential in managing gastrointestinal nematodes in small ruminants. Further in vivo studies are needed to confirm these findings. Full article

The aim of the present research is the isolation and morphological and molecular–phenological identification of nematophagous fungi of Southern Kazakhstan for the production of effective bionematicides on their basis. Nematophagous fungi, which include nematode-trapping, ovicidal, endoparasitic, toxin-producing, and special substance-producing fungi, are among the most effective biological agents in controlling phytoparasitic nematodes. To isolate and characterize nematophagous fungi, soil samples were collected at 12 sites in three regions of Southern Kazakhstan. The samples were collected using the envelope method. The content of nematophagous fungi in the samples was determined using the standard surface sowing technique. The obtained strains of nematophagous fungi were identified. The attractive and nematophagous activity of the obtained fungal strains was determined by using standard methods. In experiments on the isolation and morphological identification of nematophagous fungi, the nematode species Meloidogyne incognita was used. Identification of the strains was carried out by the method of determining the direct nucleotide sequence of the region of the nuclear ribosomal internal transcribed spacer, followed by determination of nucleotide identity with sequences deposited in the international GeneBank database. As a result, the following species of nematophagous fungi living in the soils of agricultural lands in Southern Kazakhstan were identified: Orbilia oligospora, Duddingtonia flagrans, Orbilia oligospora, and Arthrobotrys superba. Full article

New alternatives for controlling resistant populations of gastrointestinal nematodes are being studied, including the use of plant compounds and biological control with nematophagous fungi. The objective of this study was to evaluate the in vitro anthelmintic effect of linalool and its association with the fungus Duddingtonia flagrans (isolated AC001) in controlling gastrointestinal nematodes in sheep. The ovicidal activity of linalool was assessed via the Egg Hatch Test (EHT), and the larvicidal activity of linalool, alone and in combination with D. flagrans conidia, was evaluated via the Larval Motility Inhibition Test (LMIT) on infective larvae (L3). In the EHT, 100% inhibition occurred (at 1.25 and 2.5 mg/mL), with an LC50 of 0.49 mg/mL. In the LMIT, linalool alone inhibited 100% of larval motility (at 4% and 8%), with an LC50 of 0.42% or 4.2 mg/mL. In the combination of linalool with D. flagrans, there was a significant reduction in larvae, starting at 24 h, with 100% reduction after 14 days, thus being more effective in reducing L3 compared to the use of the fungus alone. It is concluded that linalool exhibits ovicidal and larvicidal activity, and its association with D. flagrans enhances the fungal predation capacity and potentiates anthelmintic efficacy. Full article

Controlling parasites in zoo animals is a significant challenge, making practical infection prevention methods essential. This study evaluated a novel solution using parasitophagous fungi-treated forage seeds to reduce soil parasite persistence. We conducted two experiments to assess the soil distribution of the fungi Mucor circinelloides (ovicidal) and Duddingtonia flagrans (larvicidal). Forage seeds were immersed in a submerged culture containing 10⁶ spores/mL and subsequently sown in plastic trays (trial 1) and demarcated ground plots (40 × 30 cm) framed with wood (trial 2). Fifteen days later, Ascaris suum and cyathostomin eggs were placed above the germinated vegetation. After a 25–30-day period, the viability of roundworm eggs reduced by 62%, and half of them remained undeveloped; a 64% reduction in the counts of L3 cyathostomins was recorded. In trial 2, viability decreased by 55% in roundworm eggs, with an infectivity rate of 30%, while L3 counts lessened by 57%. It has been concluded that the risk of infection by ascarids and cyathostomins can be reduced by at least half by sowing the soil with forage seeds pre-treated with fungi, providing a practical solution for parasite control in zoos. Full article

The emerald ash borer (EAB) is an invasive beetle that has killed hundreds of millions of ash trees throughout North America since its arrival. The use of entomopathogenic fungi as part of integrated pest management approaches is considered effective against a wide range of insect pests. The aim of this study was to screen and select locally adapted EAB-associated entomopathogenic fungi with ovicidal effect on EAB eggs under laboratory conditions. The pathogenicity of nine fungal strains, previously isolated from EAB galleries, and the commercial Beauveria bassiana strain GHA was tested. Three of these, Akanthomyces muscarius 48-27, Lecanicillium longisporum 66-14 Lecanicillium psalliotae 59-2, and GHA B. bassiana strain consistently showed significant ovicidal effects and a high percentage of inoculum recovery both from eggs and neonate larvae. The high levels of inoculum recovery from neonate larvae demonstrate that, even after emergence, larvae were infected. The possibility of disrupting EAB’s life cycle at the egg stage through microbial control represents a potential management opportunity that should be explored in future field studies. Future work should also study the effect of EPF on neonate larvae survival and performance. To our knowledge, this is the first study to evaluate the effect of entomopathogenic fungi against the egg stage of EAB. Full article

The greater wax moth (GWM, Galleria mellonella) is a prevalent pest of the honeybee and a significant risk to both honeybee populations and honeycomb storage. Research on the toxicity of essential oils (EOs) to GWM larvae has provided promising results, although their ovicidal effects and active ingredients require further study. Identifying effective plant compounds is essential for developing insecticides for GWM control. This study assessed the fumigation efficacy of 16 EOs on GWM eggs and fifth instar larvae and determined the effectiveness of these EOs and their primary components for fumigating fifth larvae. Wintergreen, star anise, and clove oils demonstrated significant insecticidal effects on GWM eggs and fifth instar larvae, resulting in a mortality rate exceeding 80% within 48 h. Gas chromatography-mass spectrometry analysis identified methyl salicylate (93.26%), trans-anethole (87.75%), and eugenol (77.75%) as the primary compounds in wintergreen, star anise, and clove oils, respectively. Further toxicity testing confirmed that these compounds were responsible for the observed insecticidal properties of the EOs. Notably, trans-anethole exhibited the lowest LC₅₀ value (25.22 μL/L) against the fifth instar larvae of GWM and significant toxicity against GWM eggs and fifth instar larvae, suggesting its potential as a viable option for the future control of GWM populations. Full article

The filtrate of the nematophagous fungus Duddingtonia flagrans produces silver nanoparticles (AgNPs) with nematicidal potential. However, there are currently no reports of its activity against Toxocara canis eggs. The aim of this study was to investigate the potential ovicidal activity of AgNPs–D. flagrans on T. canis eggs. T. canis eggs were obtained from the dissection of the uterus of adult female nematodes. After the biosynthesis of AgNPs, two experimental assays (A and B) were performed. In assay A, the ovicidal activity of AgNPs on eggs was evaluated after 15 and 30 days of interaction. In assay B, the inhibition (development) of the eggs was measured after 30 days of interaction. The results of assay A showed that the AgNPs destroyed an average of 47% of the eggs tested by the end of the experiment, causing significant structural damage. In assay B, an inhibition rate of 88% was observed at the end of 30 days. The results of the ovicidal activity of AgNP–D. flagrans were promising and indicate the potential for future studies on these biomolecules with ovicidal properties. Full article

Due to their effectiveness at low doses and relative safety for non-target species, plant essential oils (EOs) are considered ideal alternatives to conventional pesticides for pest control. In this study, the chemical composition of Thymus serpyllum (T. serpyllum) EO was construed by Gas Chromatography-Mass Spectrometry (GC-MS), and its larvicidal and ovicidal activity against omnivorous pests Spodoptera litura (S. litura) was assessed. The effects of T. serpyllum EO on the activities of antioxidant detoxification enzymes were also measured. GC–MS analysis revealed that the main constituents of T. serpyllum EO were thymol (42.1%), p-cymene (22.4%), and γ-terpinene (18.6%). In the larvicidal toxicity experiment, the T. serpyllum EO demonstrated LC50 values of 0.606 and 0.664 mg/mL against the second- and third-instar larvae of S. litura, respectively, after 48 h exposure. Moreover, an EC₅₀ value of 0.905 mg/mL was measured against S. litura eggs. In S. litura, T. serpyllum EO treatment reduced the enzymatic activity of ESTs and GST and, conversely, increased the enzymatic activity of AChE. Overall, this study demonstrated that T. serpyllum EO has the potential to be implemented as a novel eco-friendly insecticide against S. litura. Full article

Although integrated management and control programs implement intense control measures for adult, pupal, larval, and breeding sites during outbreaks, there is a lack of studies to understand the role of the vector egg stage in disease dynamics. This study aimed to assess the dry season quiescent Aedes aegypti and Aedes albopictus egg populations in houses and backyards in Tapachula, southern Mexico. Two hundred and fifty ovitraps were placed in 125 homes in the Las Americas neighborhood. A total of 7290 eggs were collected from 211 (84.4%) ovitraps. Only 5667 (77.7%) hatched under insectary water immersion and food supply conditions, with 4031 (71.1%) identified as Ae. aegypti, and 1636 (28.8%) as Ae. albopictus, respectively. The remaining 1623 (22.3%) did not hatch due to Delayed Hatching and/or quiescence tropical stage. Eighty-three larval containers were sampled with desiccated eggs during the dry season; most of them were described as trash waste because larvicides are only used for larger containers of 5–10 L. Evolutionary characteristics for the two species including partial egg hatching, ambient-regulated quiescence, the ability of the embryo to survive for a more extended period intra-seasonally, the egg sticking to inner container walls, demands urgent operational research to achieve successful egg-proof larval container methods. Full article

Ticks pose a significant threat due to their ability to lay thousands of eggs, which can persist in the environment for extended periods. While the impact of various compounds on adult and larval ticks has been studied, research on their efficacy against tick eggs is limited. This study evaluated the ovicidal activity of commercial acaricides, disinfectants, and natural products against Rhipicephalus annulatus eggs using the egg hatch assay (EHA). Deltamethrin and cypermethrin caused a non-significant inhibition of hatching (IH%), even at concentrations higher than the recommended levels. By contrast, the acaricides chlorpyrifos, phoxim, and amitraz significantly inhibited hatching at all tested concentrations. Ivermectin also demonstrated significant IH% at various concentrations but did not fully inhibit the hatching process. Among the disinfectants tested, Virkon-S^®, TH4, and Chlorox showed insignificant effects, whereas formalin achieved an IH% of only 34.1% at a high concentration of 200 mg/mL. Natural products, carvacrol and thymol, exhibited significant ovicidal activity, with a significant IH%. In a semi-field application, phoxim (0.5 mg/mL) and deltamethrin (0.05 mg/mL) were sprayed on tick eggs on pasture soil from a farm. The results indicated that phoxim-treated eggs had a 40% IH%, while deltamethrin-treated eggs showed only an 8.79% IH%. In conclusion, the acaricides amitraz, phoxim, and chlorpyrifos, as well as the natural products carvacrol and thymol, caused significant toxicity to R. annulatus eggs. Full article