Insects

Research

13 pages, 1345 KiB

Open AccessArticle

trans-α-Necrodyl Acetate: Minor Sex Pheromone Component of the Invasive Mealybug Delottococcus aberiae (De Lotto)

by Javier Marzo Bargues, Sandra Vacas, Ismael Navarro Fuertes, Daniel López-Puertollano, Jaime Primo, Antonio Abad-Somovilla and Vicente Navarro-Llopis

Insects 2025, 16(3), 318; https://doi.org/10.3390/insects16030318 - 19 Mar 2025

Viewed by 318

Abstract

Reported in Europe in the early 2000s, Delottococcus aberiae (De Lotto) (Hemiptera: Pseudococcidae) is an invasive mealybug pest that is causing severe damage to citrus production in eastern Spain. Once its main sex pheromone component was identified in a previous work as (4,5,5-trimethyl-3-methylenecyclopent-1-en-1-yl)methyl [...] Read more.

Reported in Europe in the early 2000s, Delottococcus aberiae (De Lotto) (Hemiptera: Pseudococcidae) is an invasive mealybug pest that is causing severe damage to citrus production in eastern Spain. Once its main sex pheromone component was identified in a previous work as (4,5,5-trimethyl-3-methylenecyclopent-1-en-1-yl)methyl acetate 1, the revision of virgin female effluvia is here reported to improve knowledge about the biology of D. aberiae. A new minor component has been identified in the volatile samples collected from virgin females as ((1R, 4R)-3,4,5,5-tetramethylcyclopent-2-en-1-yl)methyl acetate (trans-α-necrodyl acetate, (1R, 4R)-2), a compound also found in the essential oil of Lavandula stoechas subsp. luisieri. Bioassay testing of the activity of this compound showed that a synthetic sample of the racemate (±)-(trans)-2 was attractive to D. aberiae males both in the laboratory and field but with a lower attractant power than enantiopure (1R, 4R)-2 and (±)-(1). The 1:1 mixture of (1R, 4R)-2 and (±)-1 provided a slight additive effect. Further trials are needed to know the pest control potential of this minor compound but the possibility of obtaining this substance from a natural source could pose an important advantage to implement new methods for the sustainable control of D. aberiae. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

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14 pages, 2526 KiB

Open AccessArticle

Reticulitermes flavipes (Blattodea: Rhinotermitidae) Response to Wood Mulch and Workers Mediated by Attraction to Carbon Dioxide

by Tae Young Henry Lee and P. Larry Phelan

Insects 2025, 16(2), 194; https://doi.org/10.3390/insects16020194 - 11 Feb 2025

Viewed by 601

Abstract

The eastern subterranean termite, Reticulitermes flavipes, is challenged by the significant energy expenditures of tunnel construction for resource discovery. Subterranean termites use idiothetic mechanisms to explore large spaces, while the use of resource-specific cues for localized search is disputed. Here, termite response [...] Read more.

The eastern subterranean termite, Reticulitermes flavipes, is challenged by the significant energy expenditures of tunnel construction for resource discovery. Subterranean termites use idiothetic mechanisms to explore large spaces, while the use of resource-specific cues for localized search is disputed. Here, termite response to wood mulch, termite workers, extracts of wood mulch, and CO₂ alone were tested using a bioassay design that distinguished between attraction and arrestment. Termites showed significant attraction to wood mulch with workers or to wood mulch alone. They did not respond to workers alone at the initial dose tested, but were attracted to workers at higher densities. Termites did not respond to water or the acetone extracts of wood mulch, but did show a partial response to hexane extract compared to intact wood mulch. More significantly, when CO₂ was removed from the emissions of wood mulch and workers using soda lime, attraction was eliminated. Furthermore, termites showed a quadratic response to CO₂ concentration that peaked at ca. 14,000 ppm. The response to CO₂ alone predicted by the model matched termite response to mulch + workers when compared at the level of CO₂ they emitted. The results suggest that CO₂ is both necessary and sufficient to explain the attraction response of R. flavipes to mulch and workers we observed. It is argued that orientation to food cues complements the previously demonstrated idiothetic program to maximize the efficiency of resource location. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

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19 pages, 3989 KiB

Open AccessArticle

Factors Impacting the Use of an Allelochemical Lure in Pome Fruit for Cydia pomonella (L.) Monitoring

by Alan Lee Knight, Michele Preti and Esteban Basoalto

Insects 2025, 16(2), 172; https://doi.org/10.3390/insects16020172 - 6 Feb 2025

Cited by 1 | Viewed by 706

Abstract

A four-component blend comprising pear ester, DMNT, linalool oxide, and acetic acid (CM4K) was identified as a potent allelochemical lure for both sexes of codling moth (CM), Cydia pomonella (L.). Studies conducted from 2020 to 2022 in Washington State (USA) examined factors which [...] Read more.

A four-component blend comprising pear ester, DMNT, linalool oxide, and acetic acid (CM4K) was identified as a potent allelochemical lure for both sexes of codling moth (CM), Cydia pomonella (L.). Studies conducted from 2020 to 2022 in Washington State (USA) examined factors which could impact the lure’s relative performance. The CM4K lure was effective across a range of mating disruption programs and was equally attractive in monitoring wild and sterile CM. The lure remained attractive for at least 10 weeks. Total catch in traps baited with the CM4K was significantly less impacted than a sex pheromone lure located near mating disruption dispensers and female catches were largely unaffected. Traps with the CM4K lure caught significantly more females and fewer males when placed near clusters of fruits in a trellised orchard. Two factors were found to significantly impact the relative performance of the CM4K to sex pheromone lures: the CM4K lure was only equivalent to sex pheromone lures in pear MD orchards, and apple and pear orchards with vigorous weed growth. This is the first report of a monitoring lure for a tortricid moth being negatively impacted by the background odor of non-host weed species present within an orchard. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

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19 pages, 2016 KiB

Open AccessArticle

Volatile Cues from Fresh Cattle Dung Can Drive Horn Fly Egg-Laying and Fecal Attraction to Horn Flies, Haematobia irritans (Diptera: Muscidae)

by Javier Espinoza, Isabel Soto, Joaquín Arriagada, Marcelo Lizama, Nehuen Aninao, Washington Aniñir, Emilio M. Ungerfeld, Manuel Chacón-Fuentes and Andrés Quiroz

Insects 2025, 16(2), 129; https://doi.org/10.3390/insects16020129 - 28 Jan 2025

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Abstract

The horn fly is an economically important hematophagous ectoparasite of cattle. Its management relies heavily on broad-spectrum pesticides, which are harmful to the environment and have led to the development of resistance. Therefore, alternative control methods are needed. Semiochemicals involved in communication between [...] Read more.

The horn fly is an economically important hematophagous ectoparasite of cattle. Its management relies heavily on broad-spectrum pesticides, which are harmful to the environment and have led to the development of resistance. Therefore, alternative control methods are needed. Semiochemicals involved in communication between horn flies and their host are a promising alternative. Considering that the egg-laying of this fly occurs almost exclusively in fresh cattle dung, and most parts of its life cycle occur totally in dung, dung volatiles might play an important role in horn fly behavior. Therefore, the main aim of this study was to evaluate the effects of volatile blends and compounds emitted from fresh/aged cattle dung on the olfactory response and oviposition of horn flies. Dung blends were captured and analyzed by SPME-GC/MS. p-Cresol was the most abundant compound in dung blends, followed by α- and β-pinene, limonene, and β-caryophyllene, among other common dung volatiles. Fresh-dung volatiles attracted males and females in a Y-tube olfactometer, and they elicited the egg-laying of flies in two-choice tests. p-Cresol and α-pinene were attractive to females and they elicited higher oviposition, demonstrating that dung volatile semiochemicals, in part, lend to dung attractiveness and stimulate the horn fly oviposition. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

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12 pages, 245 KiB

Open AccessArticle

Comparison of Pheromone Lures and Sticky Pad Color for Capturing Tuta absoluta (Lepidoptera: Gelechiidae)

by Muhammad Sadique, Muhammad Ishtiaq, Mirza Abdul Qayyum, Wafa A. H. Alkherb, Asim Abbasi, Muhammad Arshad, Unsar Naeem Ullah, Nazar Faried, Muhammad Irfan Akram and Nazih Y. Rebouh

Insects 2025, 16(1), 94; https://doi.org/10.3390/insects16010094 - 17 Jan 2025

Viewed by 1199

Abstract

Tomato leaf miner Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has gained the status of major pest globally. Integrated pest management (IPM) consists of different control methods. This field study was conducted to evaluate the influence of different pheromone-based traps to attract the male population [...] Read more.

Tomato leaf miner Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has gained the status of major pest globally. Integrated pest management (IPM) consists of different control methods. This field study was conducted to evaluate the influence of different pheromone-based traps to attract the male population and the potential of sticky pads of four different colors in capturing the adults in the absence of pheromone lures. The trials were conducted in Khyber Pakhtunkhwa (Pakistan) for two consecutive years, 2020 and 2021. The Delta trap with rubber septum type lure was significantly more attractive in both years, with mean number of capturing 76.0 and 86.17, as compared to polymer wax (32.83 and 28.2) and polymer vial (10.37 and 11.77), lures. The highest mean number of capturing of T. absoluta adults were noted as 17.93 and 21.73 with black color sticky trap without pheromone, whereas the lowest number of adults, i.e., 1.33 and 1.47, were captured during the first and second year of the study, respectively, with yellow color sticky traps. However, a significant difference was found in pheromone lures and among black, red, green, and yellow color sticky pads. Hence, Delta traps equipped with rubber septum pheromones lures and black colored sticky pads were more useful for the control of T. absoluta than any other colored sticky pads and pheromone lures alone. These findings could be helpful for the integrated management of T. absoluta. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

13 pages, 1597 KiB

Open AccessArticle

Pheromones in Crane Flies: Behaviorally Active Cuticular Compounds in Tipula autumnalis Loew (Diptera: Tipulidae)

by Vincas Būda, Violeta Apšegaitė, Laima Blažytė-Čereškienė, Sigitas Podėnas, João Pedro de A. Souza, Paulo H. G. Zarbin, Linas Labanauskas, Tomas Paškevičius, Vilma Baužienė and Sandra Radžiutė

Insects 2025, 16(1), 24; https://doi.org/10.3390/insects16010024 - 29 Dec 2024

Viewed by 979

Abstract

The pheromones of crane flies (Tipulidae), one of the largest families within the order Diptera (over 15,000 species), are unknown. The aim of our study was to identify the chemical compounds involved in communication in Tipula autumnalis, a representative species of the [...] Read more.

The pheromones of crane flies (Tipulidae), one of the largest families within the order Diptera (over 15,000 species), are unknown. The aim of our study was to identify the chemical compounds involved in communication in Tipula autumnalis, a representative species of the family. Female cuticular washes were found to be attractive to males in a bioassay. GC-EAD analysis revealed nine EAG-active compounds, which were identified as cuticular hydrocarbons (CHCs). Both males and females contained these CHCs, though in different ratios. The strongest antennal responses in male T. autumnalis were evoked by n-pentacosane, (Z)-9-pentacosene, and (Z, E)-6,9-pentacosadiene, which were the predominant components in females. Each of these compounds were attractive to males in the behavioral assay and are therefore attributed to the female sex pheromone of T. autumnalis. (Z)-9-tricosene and (R)-3-methylheneicosane elicited both EAG and behavioral responses in males and were abundant in washes from same-sex individuals. In addition to the compounds involved in female–male interactions, it is evident that T. autumnalis also employs CHCs in male–male interactions. The exact roles of some compounds remain undetermined. Among the semiochemicals, the established stereostructure of (Z, E)-6,9-pentacosadiene and the olfactory/behavioral effects of (R)- and (S)-3-methylheneicosane were novel findings in insects. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

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Review

Jump to: Research, Other

31 pages, 469 KiB

Open AccessReview

What Can We Learn from Dissecting Tortricid Females About the Efficacy of Mating Disruption Programs?

by Alan Lee Knight, Michele Preti and Esteban Basoalto

Insects 2025, 16(3), 248; https://doi.org/10.3390/insects16030248 - 28 Feb 2025

Viewed by 650

Abstract

Female mating success for the tortricids codling moth (CM), Cydia pomonella, Oriental fruit moth (OFM), Grapholita molesta, European grape vine moth (EGVM), Lobesia botrana, and five leafroller (LR) species under various mating disruption (MD) programs was reviewed at a time [...] Read more.

Female mating success for the tortricids codling moth (CM), Cydia pomonella, Oriental fruit moth (OFM), Grapholita molesta, European grape vine moth (EGVM), Lobesia botrana, and five leafroller (LR) species under various mating disruption (MD) programs was reviewed at a time when new dual sex lures can provide alternative tools to assess female mating. Previous reliance on passive assessments such as tethering and virgin female-baited traps with laboratory moths are at odds with active trapping methods of wild moths. Additive factors such as delayed mating, adjustments in female behaviors, and greater levels of natural control may or may not contribute to the apparent success of MD. Current MD programs are not based solely on research, as economics and commercialization require some compromise. The complete sex pheromone blend is not always used. A delay in mating has been reported from the field with one study and suggested that reductions in fecundity would likely be minimal. There is no evidence that MD works better with low population densities. MD is an established technology, but the new dual sex lures are showing that the density of mated females is rather high. Efforts to improve the efficacy of MD are ongoing with a small cadre of researchers. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

Other

Jump to: Research, Review

11 pages, 3209 KiB

Open AccessBrief Report

Functional Investigation of the Receptor to the Major Pheromone Component in the C-Strain and the R-Strain of the Fall Armyworm Spodoptera frugiperda

by Arthur Comte, Alizée Delarue, Marie-Christine François, Christelle Monsempes, Camille Meslin, Nicolas Montagné and Emmanuelle Jacquin-Joly

Insects 2025, 16(3), 304; https://doi.org/10.3390/insects16030304 - 14 Mar 2025

Viewed by 480

Abstract

The fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important invasive polyphagous crop pest that has been invading the world since 2016. This species consists of two strains adapted to different host plants, the corn strain and the rice strain, which also exhibit [...] Read more.

The fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important invasive polyphagous crop pest that has been invading the world since 2016. This species consists of two strains adapted to different host plants, the corn strain and the rice strain, which also exhibit differences in their mating behavior, pheromone composition, and pheromone receptor sequences. A way to monitor invasion and control this pest is the use of synthetic sex pheromones to trap adults and disturb the mate-finding process via the release of large amounts of pheromones in the air. However, the efficiency of these methods depends on the specificity and sensitivity of the corresponding pheromone receptors. Yet, only pheromone receptors of the corn strain have been characterized, and nothing is known about the specificity and sensitivity of the rice strain orthologues. To address this gap, we functionally expressed the receptors to the major sex pheromone component of the two strains in Drosophila olfactory sensory neurons and challenged them with a large panel of pheromone compounds using single-sensillum recordings. Although their sequences present subtle mutations, we revealed that they share similar response spectra and sensitivity. The implications of these results on pheromone-based pest management strategies are discussed. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

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