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Ecology and Evolution Jun 2024Asynchronous migration of insect herbivores and their host plants towards higher elevations following climate warming is expected to generate novel plant-insect...
Asynchronous migration of insect herbivores and their host plants towards higher elevations following climate warming is expected to generate novel plant-insect interactions. While the disassociation of specialised interactions can challenge species' persistence, consequences for specialised low-elevation insect herbivores encountering novel high-elevation plants under climate change remain largely unknown. To explore the ability of two low-elevation Lepidoptera species, and , to undergo shifts from low- to high-elevation host plants, we combined a translocation experiment performed at two elevations in the Swiss Alps with experiments conducted under controlled conditions. Specifically, we exposed . and . to current low- and congeneric high-elevation host plants, to test how shifts in host plant use impact oviposition probability, number of eggs clutches laid, caterpillar feeding preference and growth, pupation rate and wing size. While our study shows that both . and . can oviposit and feed on novel high-elevation host plants, we reveal strong preferences towards ovipositing and feeding on current low-elevation host plants. In addition, shifts from current low- to novel high-elevation host plants reduced pupation rates as well as wing size for . , while caterpillar growth was unaffected by host plant identity for both species. Our study suggests that populations of . and . have the ability to undergo host plant shifts under climate change. However, these shifts may impact the ability of populations to respond to rapid climate change by altering developmental processes and morphology. Our study highlights the importance of considering altered biotic interactions when predicting consequences for natural populations facing novel abiotic and biotic environments.
PubMed: 38932969
DOI: 10.1002/ece3.11596 -
Life (Basel, Switzerland) May 2024The oriental fruit fly, (Hendel), poses a significant threat to the global fruit industry, causing damage to diverse fruits like citrus, mango, and guava. Chemical...
The oriental fruit fly, (Hendel), poses a significant threat to the global fruit industry, causing damage to diverse fruits like citrus, mango, and guava. Chemical pesticides have limited effectiveness, and pesticide residues and pesticide resistance are pressing issues. Therefore, it is essential to develop environmentally friendly pest control methods to address this problem. Behavior-modifying chemicals, including male attractants and intersex protein baits, play a critical role in the control of . The mature host fruit serves as both an oviposition site and food source under natural conditions, making it a potential attraction source for oriental fruit flies. Orange, , is a main host of , and commercial orange juice is a common attractant for the egg laying of . Although it can both attract and elicit oviposition behaviors in adults, its active components are still unclear. This study utilized analytical chemistry, behavioral tests, and electrophysiology to identify the active components of commercial orange juice that attract , with the aim of providing a reference for the development of behavior-modifying chemical-based techniques to control Five compounds with a high abundance were identified via a GC-MS, including D-Limonene, butanoic acid ethyl ester, β-myrcene, linalool, and α-terpineol. Behavioral and electrophysiological experiments uncovered that D-Limonene was the active substance that was the main attractant in the mixture of these five substances, evoking a strong electrophysiological response in adult . D-Limonene strongly attracts adult only when they are sexually mature, and the attraction is not rhythmic. Olfaction plays a leading role in the attraction of D-Limonene to adult , and mediates the perception of D-Limonene by . Overall, D-Limonene is one of the key attractant compounds for in the volatile compounds of commercial orange juice, offering possible support for the development of behavior-modifying chemical-based technology to control in the future.
PubMed: 38929696
DOI: 10.3390/life14060713 -
Tropical Medicine and Infectious Disease May 2024Diverse larval habitats significantly influence female mosquito oviposition. Utilizing traps that simulate these habitats is helpful in the study of the bioecology and...
Applicability of Traps for Collecting Mosquito Immatures (Diptera: Culicidae) for Entomological Surveillance of Arbovirus Vectors in a Remnant of the Atlantic Forest, Rio de Janeiro State, Brazil.
Diverse larval habitats significantly influence female mosquito oviposition. Utilizing traps that simulate these habitats is helpful in the study of the bioecology and characteristics of pathogen-transmitting species during oviposition. This study evaluated the feasibility of different traps in natural environments by comparing sampling methods and detecting the oviposition of epidemiologically important mosquitoes, with emphasis on species, in a fragment of the Atlantic Forest in Silva Jardim, Rio de Janeiro State, Brazil. Monthly collections were conducted from March 2021 to October 2023 using four types of traps: plastic containers, tires, bamboo, and sapucaia. Immatures were collected from these traps using a pipette, placed in plastic bags, and transported to the laboratory. Tire was the most efficient trap, showing the highest mosquito abundance (n = 1239) and number of species (S = 11). Conversely, the plastic container trap exhibited the lowest diversity (H = 0.43), with only two species and a low mosquito abundance (n = 26). The bamboo trap captured six species and recorded the second-highest diversity index (H = 1.04), while the sapucaia trap captured five species and had the third-highest diversity index (H = 0.91). Of the total immatures collected, 1817 reached adulthood, comprising 13 species, two of which are vectors of the sylvatic yellow fever virus: and . In conclusion, detecting key vectors of the sylvatic yellow fever virus in Brazil highlights the need for ongoing entomological and epidemiological surveillance in the study area and its vicinity. These efforts are crucial for monitoring vector presence and activity, identifying potential transmission hotspots, and devising effective control and prevention strategies.
PubMed: 38922037
DOI: 10.3390/tropicalmed9060125 -
Insects Jun 2024Insect pheromones have been intensively studied with respect to their role in insect communication. However, scarce knowledge is available on the impact of pheromones on...
Insect pheromones have been intensively studied with respect to their role in insect communication. However, scarce knowledge is available on the impact of pheromones on plant responses, and how these in turn affect herbivorous insects. A previous study showed that exposure of pine () to the sex pheromones of the pine sawfly results in enhanced defenses against the eggs of this sawfly; the egg survival rate on pheromone-exposed pine needles was lower than that on unexposed pine. The long-lasting common evolutionary history of and suggests that has developed counter-adaptations to these pine responses. Here, we investigated by behavioral assays how copes with the defenses of pheromone-exposed pine. The sawfly females did not discriminate between the odor of pheromone-exposed and unexposed pine. However, when they had the chance to contact the trees, more unexposed than pheromone-exposed trees received eggs. The exposure of pine to the pheromones did not affect the performance of larvae and their pupation success. Our findings indicate that the effects that responses of pine to sex pheromones exert on the sawfly eggs and sawfly oviposition behavior do not extend to effects on the larvae.
PubMed: 38921172
DOI: 10.3390/insects15060458 -
Insects Jun 2024Using semiochemicals collected from spotted lanternflies (Hemiptera: Fulgoridae) (SLF) and deployed in the field with circle traps, we demonstrated that SLF responded...
Using semiochemicals collected from spotted lanternflies (Hemiptera: Fulgoridae) (SLF) and deployed in the field with circle traps, we demonstrated that SLF responded to SLF pheromones: in particular, this was the case for males while seeking mates and for females while ovipositing. The attractants consisted of SLF body extract emitted from diffuser lures and SLF honeydew on burlap ribbons, collected from heavily infested locations. Traps with attractants were deployed in field sites with very light SLF infestations to avoid competing signals of pre-existing aggregations. The number of SLF equivalents emitted by each diffuser per trapping period was used in a dose-response analysis. Three trees per block received either (1) a control hexane lure and a clean ribbon, (2) a lure containing SLF extract and a clean ribbon, or (3) a lure containing SLF extract and a honeydew-laden ribbon. Ten blocks were sampled three times per week for twelve weeks. We found a significant positive dose-response by males to SLF body extract only in the presence of SLF honeydew, indicating a synergistic effect between honeydew volatiles and body volatiles. This dose-response occurred for five weeks after mating started, after which males no longer responded. Subsequently, females had a significant positive dose-response to SLF extract only in the presence of honeydew when oviposition was their primary activity, continuing for two weeks, suggesting that females may use pheromones to aggregate for oviposition. The extract in the absence of honeydew did not result in a positive dose-response, nor did the hexane control. These findings suggest that SLF respond synergistically to the combination of pheromones present in both SLF honeydew and SLF bodies. Thus, combining key components from both sources may aid the development of semiochemical lures for SLF.
PubMed: 38921162
DOI: 10.3390/insects15060447 -
Insects Jun 2024Attelabidae insects have attracted much attention due to their unique leaf rolling behavior before oviposition. However, the lack of genomic data makes it difficult to...
Attelabidae insects have attracted much attention due to their unique leaf rolling behavior before oviposition. However, the lack of genomic data makes it difficult to understand the molecular mechanism behind their behavior and their evolutionary relationship with other species. To address this gap, we utilized Illumina and Nanopore sequencing platforms along with Hi-C technology to establish a highly accurate whole genome of at the chromosome level. The resulting genome size was determined to be 619.26 Mb, with a contig N50 of 50.89 Mb and GC content of 33.89%. Moreover, a total of 12,572 genes were identified, with 82.59% being functionally annotated, and 64.78% designated as repeat sequences. Our subsequent phylogenetic tree analysis revealed that Attelabidae's divergence from Curculionidae occurred approximately 161.52 million years ago. Furthermore, the genome of contained 334 expanded gene families and 1718 contracted gene families. In addition, using Phylogenetic Analysis by Maximum Likelihood (PAML), we identified 106 rapidly evolved genes exhibiting significant signals and 540 positively selected genes. Our research endeavors to serve as an invaluable genomic data resource for the study of Attelabidae, offering fresh perspectives for the exploration of its leaf rolling behavior.
PubMed: 38921146
DOI: 10.3390/insects15060431 -
Insects Jun 2024Insect life processes and reproductive behaviors are significantly affected by extremely high temperatures. This study focused on , which poses a severe threat to tomato...
Insect life processes and reproductive behaviors are significantly affected by extremely high temperatures. This study focused on , which poses a severe threat to tomato cultivars. The effects of intense heat stress on the growth, development, oviposition, and longevity of were investigated. This investigation encompassed various developmental stages, including eggs, pupae, and adults. This study revealed that egg hatching and pupa emergence rates were significantly reduced at a temperature of 44 °C maintained for 6 h. The longevity of adults that emerged after the egg and pupal stages were exposed to 44 °C for 6 h was significantly reduced compared to the control. Notably, there was no significant variation in adult fecundity after egg-stage exposure to high temperatures. However, all treatments exhibited significantly reduced fecundity compared to the control after exposure to high temperatures during the pupal stage. Adult survival rates after exposure to 40 °C and 44 °C for 3 h were 74.29% and 22.40%, respectively, dramatically less than that of the control, which was 100%. However, no significant differences were noted in terms of longevity and egg production. These results offer a better understanding of the complex interactions between extreme temperatures and the life history traits of , thereby offering valuable insights for implementing management strategies to alleviate its impact on tomato crops in response to climate change.
PubMed: 38921138
DOI: 10.3390/insects15060423 -
Insects May 2024The volatile organic compounds (VOCs) of plant hosts allow insect localization through olfactory recognition. In this study, the oviposition behavior of the codling moth...
The volatile organic compounds (VOCs) of plant hosts allow insect localization through olfactory recognition. In this study, the oviposition behavior of the codling moth was investigated and the VOCs from different walnut organs were extracted and analyzed to systematically study their composition and content differences. The electrophysiological and behavioral responses of the codling moth to walnut VOCs were measured using gas chromatography-electroantennographic detection (GC-EAD) and a four-arm olfactometer to screen the key active contents. The field investigation results indicated that 90.3% of the eggs spawned by the first generation of adult codling moths were adjacent to the walnut fruits. Walnut VOCs are mainly composed of terpenes, aromatics, and alkanes. Twelve VOCs can produce electroantennogenic (EAG) responses in the codling moths. Both adult males and females exhibit concentration dependence, with notable disparities in their EAG response levels. In the olfactory behavioral bioassay, linalool, eucalyptol, and high doses of geranyl acetate showed repellent effects on the codling moths, while myrcene, β-ocimene, nonanal, methyl salicylate, α-farnesene, and heptaldehyde showed the opposite. The relative levels of heptaldehyde, geranyl acetate, nonanal, and methyl salicylate were high in the fruits, which is intimately related to the localization of the walnut fruit by females. These VOCs can influence the oviposition behavior of codling moths but their application in the control of this pest needs to be confirmed and improved through further field experiments.
PubMed: 38921117
DOI: 10.3390/insects15060402 -
F1000Research 2023The research focused on evaluating the biological and reproductive parameters of the species with the introduction of field genetic material, in the Noctuid Insect...
BACKGROUND
The research focused on evaluating the biological and reproductive parameters of the species with the introduction of field genetic material, in the Noctuid Insect Breeding Laboratory.
METHODS
The experiment consisted of three treatments and three repetitions involving 30 individuals each. Field-collected S. sunia population was reared in the laboratory under semi-controlled conditions of temperature and humidity for three generations. The progeny of the third generation was crossed with the laboratory population and the resulting progeny was observed for growth and reproductive fitness.
RESULTS
The results revealed that the hybrid progeny (T3) has a sex ratio (F: M) of 0.82, as against 1.22 and 0.76 observed in the field (T1) and lab populations (T2) respectively. The T1 females oviposited 196 egg masses as against 160 and 59 egg masses by T3 and T2 females respectively. The larval growth was more in hybrid progeny with shorter larval duration. However, no variation was observed in the incubation and pupal periods.
CONCLUSIONS
Since the most optimal results were obtained in T2 and T3, it is recommended to introduce genetic material every six months to maintain a good laboratory population of the insect host under study and better breeding of its natural enemies.
Topics: Animals; Female; Male; Larva; Oviposition; Spodoptera; Crosses, Genetic; Reproduction; Genetic Fitness; Laboratories; Sex Ratio
PubMed: 38919837
DOI: 10.12688/f1000research.129183.3 -
Current Biology : CB Jun 2024The diversity of insect eggs is astounding but still largely unexplained. Here, we apply phylogenetic analyses to 208 species of stick and leaf insects, coupled with...
The diversity of insect eggs is astounding but still largely unexplained. Here, we apply phylogenetic analyses to 208 species of stick and leaf insects, coupled with physiological measurements of metabolic rate and water loss on five species, to evaluate classes of factors that may drive egg morphological diversification: life history constraints, material costs, mechanical constraints, and ecological circumstances. We show support for all three classes, but egg size is primarily influenced by female body size and strongly trades off with egg number. Females that lay relatively fewer but larger eggs, which develop more slowly because of disproportionately low metabolic rates, also tend to bury or glue them in specific locations instead of simply dropping them from the foliage (ancestral state). This form of parental care then directly favors relatively elongated eggs, which may facilitate their placement and allow easier passage through the oviducts in slender species. In addition, flightless females display a higher reproductive output and consequently lay relatively more and larger eggs compared with flight-capable females. Surprisingly, local climatic conditions had only weak effects on egg traits. Overall, our results suggest that morphological diversification of stick insect eggs is driven by a complex web of causal relationships among traits, with dominant effects of resource allocation and oviposition strategies, and of mechanical constraints.
PubMed: 38897201
DOI: 10.1016/j.cub.2024.05.042