Female Oviposition Research Articles

Effects of Sugar in Adult Diet on the Development and Reproduction of Spodoptera frugiperda (J. E. Smith) under Laboratory Conditions in Burkina Faso

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is the pest causing enormous economic losses to Maize production. To date, there is little documentation on rearing protocols for S. frugiperda. This study aimed to evaluate the effect of honey and glucose as a nutrient source on the developmental parameters and reproduction of S. frugiperda under laboratory conditions. In this work, we compared the larval period, larval survival, pupal period, pupal survival, adult longevity, female oviposition period, female fecundity and egg hatching of S. frugiperda adults under three feed diets: distilled water (D1), 10% bee honey with water solution (D2) and 10% glucose with water (D3). The longest larval period and highest larval survival were achieved on D3. The longest longevity, oviposition and post-oviposition periods, the highest fecundity and number of eggs per female per day were observed on D3. The diet D3 had significant effects on live cycle of S. frugiperda parameters compared with D1 and D2. Our results will enable us to improve mass rearing of S. frugiperda in laboratory.

Response of the tomato leaf miner Phthorimaea absoluta to wild and domesticated tomato genotypes.

Phthorimaea absoluta, a highly destructive invasive pest, poses a significant threat to tomato production globally. Exploring alternative control methods, such as host plant resistance can contribute to diminish reliance on insecticides and promote sustainable integrated pest management (IPM) practices. Thus, the identification of new P. absoluta-resistant tomato cultivars and potential wild sources for breeding programmes remains imperative. We evaluated the effect of 19 tomato genotypes, comprising 16 domesticated varieties and three wild tomato species, on oviposition output of female P. absoluta, as well as on larval performance under no-choice conditions using detached leaves. We also characterized and quantified glandular and nonglandular trichomes, exploring their potential correlation with the response of P. absoluta to the tomato plants. Generally, fewer eggs were oviposited on domesticated plants, whereas the wild tomatoes Solanum arcanum and S. neorickii and the domesticated tomato Corona F1 impaired larval development. The pest larvae consumed a limited area of leaflets from S. arcanum and S. neorickii compared to other genotypes, leading to the lowest weights in both male and female pupae. All tomato plants exhibited a prevalence of nonglandular over glandular trichomes, except for S. arcanum, which exhibited a higher abundance of glandular trichomes. Although higher trichome density correlated with longer larval settlement on the leaflets, it did not influence female oviposition. Our findings demonstrate that the wild tomatoes S. arcanum and S. neorickii could be considered as potential sources for breeding programmes, and the domesticated Corona F1 could offer IPM options against P. absoluta. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The leaf-footed cactus bug is not a cactus specialist: Narnia femorata feeds, fights, and mates on thistle.

Novel host plants are incorporated into the diets of phytophagous insects when females oviposit and juveniles feed and survive on them. A change in diet, however, can have morphological consequences. We recently found a population of the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae), a historical cactus specialist, living and feeding on Cirsium thistle. We also found adults breeding and males using their enlarged hind legs (i.e., weapons) in male-male combat on thistle. When we compared this thistle population with a population feeding on cactus, we found that both populations had similar body and weapon sizes as well as weapon composition. However, the population living on thistle had longer mouthparts than the population found on cactus, although this difference only occurred at larger body sizes. This difference in adult mouthpart size is likely a result of the juvenile rearing environment (i.e., thistle or cactus). However, genetic differences may also affect this trait. Our results provide some interesting avenues for future research (e.g., a reciprocal transplant experiment) in a species with a recent host range expansion.

Ceracis luci sp. nov., the first Ciidae species (Coleoptera: Tenebrionoidea) from the Caatinga biome.

Ceracis luci sp. nov., the first Ciidae species from the Caatinga biome, is described based on individuals collected in Licínio de Almeida, in the state of Bahia, Northeast Brazil. The species is recognizable mainly by the following characteristics: antennae with 8 antennomeres and subseriate elytral punctation; male anterocephalic edge produced forward and slightly elevated upward forming a wide lamina with a straight edge (when seen from above); male anterior edge of pronotum produced forward as a plate deeply emarginate at middle forming two horns, almost parallel to each other and with rounded apices; and female ovipositor lacking gonostyli. Ceracis luci sp. nov. is morphologically similar to Ceracis pullulus (Casey), for which we provide information on the morphology of the abdominal terminalia of males and females and new geographic distribution records.

Herbicide Stress Inducesbeetle Oviposition on Red Maples.

Flatheaded borers (FHB; Chrysobothris spp.), are woodboring-beetles that lay their eggs in the bark and cambium of deciduous trees in North America. Females often target stressed host-plants for oviposition. The reason why is unknown; however, stressed plants often suffer various induced phytochemical changes that may enhance larval infestation success depending on the stressor such as induced upregulation of defenses, reallocation of nutrients, and changes to volatile organic compound (VOC) emissions. To understand attraction of FHB to specific stress-induced changes, we analyzed phytochemical changes associated with stress treatments and attractiveness maple trees to FHB. Trees were stressed by: (1) chemical stress (pelargonic acid herbicide), (2) physical stress (physically removing leaves), and (3) physical stress (removing portions of bark near the root crown). After reflush of defoliated trees, bark tissues where FHB larvae feed were analyzed for nutritional changes (carbon and nitrogen), anti-nutritive changes (polyphenols and tannins) and emissions of foliar VOCs. At the end of the growing season, trees were assessed for FHB larval presence and oviposition attempts. There were more larvae and oviposition attempts on trees stressed by herbicide application. Compared to other treatments, herbicide-stressed trees had greater nitrogen and total polyphenol concentrations. Greater nitrogen may play a role in the fitness of feeding larvae, and the greater polyphenol concentration may stimulate female oviposition in the herbicide stressed trees. Females may be able to locate the herbicide-stressed trees by using volatile cues such as increases in limonene, α-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and hexenyl acetate.

Suitability of Different Ovipositional Trap for Black Soldier Fly (Hermetia illucens)

The Black Soldier Fly (Hermetia illucens) has garnered significant attention as a sustainable and nutrient-rich option for poultry feed, due to its high protein and fat content. This study assesses the oviposition preference of female black soldier flies among different ovipositional traps like cardboard, wood, corrugated plastic tubes, and an outside area within a controlled environment. Employing a completely randomized block design, we assessed a range of parameters, including ovipositional trap selection, oviposition duration, egg count, fertility, offspring development, and mortality rate. The findings revealed that plastic tubes were the most favoured ovipositional trap, attracting 142.67 female visits, with an impressive average egg-laying duration of 13 minutes and an egg fertility rate of 85.33%. Such preference may be due to the optimal microenvironment plastic material provides for oviposition of the Soldier fly females. Cardboard traps garnered 122.67 visits, with a notable 10.67-minute egg-laying duration and a fertility rate of 72.67%. Interestingly, wood traps were the least attractive, with only 52.33 visits, the shortest egg-laying duration (6 minutes), and a fertility rate of 33.67%. These results demonstrate the significant role that material choice plays in the reproductive success of Hermetia illucens. The corrugated plastic tubes are the best ovipositional traps for the efficient mass-rearing of black soldier flies for both research and commercial requirements.

Infestation of Rice Striped Stem Borer (Chilo suppressalis) Larvae Induces Emission of Volatile Organic Compounds in Rice and Repels Female Adult Oviposition.

Plants regulate the biosynthesis and emission of metabolic compounds to manage herbivorous stresses. In this study, as a destructive pest, the pre-infestation of rice striped stem borer (SSB, Chilo suppressalis) larvae on rice (Oryza sativa) reduced the subsequent SSB female adult oviposition preference. Widely targeted volatilomics and transcriptome sequencing were used to identify released volatile metabolic profiles and differentially expressed genes in SSB-infested and uninfested rice plants. SSB infestation significantly altered the accumulation of 71 volatile organic compounds (VOCs), including 13 terpenoids. A total of 7897 significantly differentially expressed genes were identified, and genes involved in the terpenoid and phenylpropanoid metabolic pathways were highly enriched. Correlation analysis revealed that DEGs in terpenoid metabolism-related pathways were likely involved in the regulation of VOC biosynthesis in SSB-infested rice plants. Furthermore, two terpenoids, (-)-carvone and cedrol, were selected to analyse the behaviour of SSB and predators. Y-tube olfactometer tests demonstrated that both (-)-carvone and cedrol could repel SSB adults at higher concentrations; (-)-carvone could simultaneously attract the natural enemies of SSB, Cotesia chilonis and Trichogramma japonicum, and cedrol could only attract T. japonicum at lower concentrations. These findings provide a better understanding of the response of rice plants to SSB and contribute to the development of new strategies to control herbivorous pests.

Evaluation of the Potential Flight Ability of the Casuarina Moth, Lymantria xylina (Lepidoptera: Erebidae).

Lymantria xylina Swinhoe (Lepidoptera: Erebidae) is a potentially invasive pest, similar to Lymantria dispar asiatica Vnukovskij and Lymantria dispar japonica Motschulsky (Lepidoptera: Erebidae). To evaluate its potential for spread and flight distance related to egg deposition on vessels at ports, we employed a flight mill to assess the flight capabilities of its adults under varying conditions. Our findings revealed that females primarily flew short distances and ceased flying after 3:00 AM, whereas males covered much longer distances throughout the day. Sex, age, and flight duration significantly influenced flight ability. Females exhibited weaker flight capability than males, and their ability declined with increasing age or flight duration. Notably, 1-day-old moths displayed the strongest flight ability, with average flight distances of up to 3.975 km for females and 8.441 km for males. By the fifth day, females no longer flew, and males experienced reduced flight ability. After continuous hanging for 16 h, females lost most of their flight capacity, while males remained capable of flight even after 32 h. Additionally, female flight ability decreased significantly after mating, possibly due to factors such as egg-carrying capacity, weight, and load ratio. This study provides a foundation for assessing the risk of long-distance dispersal of L. xylina via ocean-going freighters, considering female moths' phototactic flight and oviposition.

A Female-Biased Chemosensory Protein PxutCSP19 in the Antennae of Papilio xuthus Tuned to Host Volatiles and Insecticides.

Chemosensory protein (CSP) genes significantly enriched in the female antennae are potential molecular candidates for mediating female oviposition behaviors. In this study, we presented the interaction mechanisms of a female-antenna-biased PxutCSP19 in Papilio xuthus to 47 host volatiles, four biopesticides and 24 synthetic insecticides. Using a bioinformatics-based homology search, 22 genes orthologous to PxutCSP19 were identified from 22 other Papilio butterflies with high sequence identities to each other (73.20~98.72%). Multiple alignment analyses revealed a particularly extended N-terminus of Papilio CSP19s (an average of 154 residues) compared to insects' typical CSPs (approximately 120 residues). The expression profiles indicated that PxutCSP19 was significantly enriched in the female antennae, with a 31.81-fold difference relative to the male antennae. In ligand-binding assays, PxutCSP19 could strongly bind six host odorants with high affinities, ranging from dissociation constant (Ki) values of 20.44 ± 0.64 μM to 22.71 ± 0.73 μM. Notably, this protein was tuned to a monoterpenoid alcohol, linalool, which generally existed in the Rutaceae plants and elicited electrophysiological and behavioral activities of the swallowtail butterfly. On the other hand, PxutCSP19 was also capable of binding eight insecticides with stronger binding abilities (Ki < 12 μM) compared to host odorants. When an extended N-terminal region of PxutCSP19 was truncated into two different proteins, they did not significantly affect the binding of PxutCSP19 to ligands with high affinities, suggesting that this extended N-terminal sequences were not involved in the specificity of ligand recognition. Altogether, our study sheds light on the putative roles of PxutCSP19 enriched in the female antennae of P. xuthus in the perception of host volatiles and the sequestering of insecticides, and it complements the knowledge of butterfly CSPs in olfaction and insecticide resistance.

A comparative approach for life history and functional response demonstrates similar survival strategies for Trichogramma evanescens and T. pintoi.

Egg parasitoids are important biological control agents of lepidopteran pests of agricultural crops. Trichogramma evanescens Westwood and T. pintoi Voegele (Hymenoptera: Trichogrammatidae) are egg parasitoids with worldwide importance. The parasitoid selection necessitates comparative assessment of the life table traits and functional response analysis to provide insights into their effectiveness in pest control. In this study, we examined theirlife table traits including survivorship and reproductivity, and functional response and associated parameters i.e., attack coefficient and handling time. Life table parameters, using age-stage, two-sex theory, revealed similar survival and reproductive strategies for both species. For example, the female longevity, oviposition days and fecundity did not differ between both species. Exceptionally, the male longevity of T. evanescens was shorter than that of T. pintoi. The population growth parameters such as gross reproductive rate (GRR), net reproductive rate (R0), intrinsic rate of increase (r), finite rate of increase (λ), and mean generation time (T) did not differ between species. The polynomial logistic regression yielded a type III functional response and a non-linear least square analysis revealed different attack coefficient and similar handling time. However, their parasitism rate differed between the lowest (five eggs) and highest (80 eggs) initial host egg densities such that T. evanescens had a lower parasitism rate at the lowest density and higher parasitism rate at the highest density. The similarity in survival strategies and minor differences in host handling of both parasitoids are discussed in terms of relevance to applied biological control applications and evolutionary traits. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Comparative connectomics of the descending and ascending neurons of the Drosophila nervous system: stereotypy and sexual dimorphism.

In most complex nervous systems there is a clear anatomical separation between the nerve cord, which contains most of the final motor outputs necessary for behaviour, and the brain. In insects, the neck connective is both a physical and information bottleneck connecting the brain and the ventral nerve cord (VNC, spinal cord analogue) and comprises diverse populations of descending (DN), ascending (AN) and sensory ascending neurons, which are crucial for sensorimotor signalling and control. Integrating three separate EM datasets, we now provide a complete connectomic description of the ascending and descending neurons of the female nervous system of Drosophila and compare them with neurons of the male nerve cord. Proofread neuronal reconstructions have been matched across hemispheres, datasets and sexes. Crucially, we have also matched 51% of DN cell types to light level data defining specific driver lines as well as classifying all ascending populations. We use these results to reveal the general architecture, tracts, neuropil innervation and connectivity of neck connective neurons. We observe connected chains of descending and ascending neurons spanning the neck, which may subserve motor sequences. We provide a complete description of sexually dimorphic DN and AN populations, with detailed analysis of circuits implicated in sex-related behaviours, including female ovipositor extrusion (DNp13), male courtship (DNa12/aSP22) and song production (AN hemilineage 08B). Our work represents the first EM-level circuit analyses spanning the entire central nervous system of an adult animal.

First evidence of sperm remains on penis after mating in Opiliones (Opiliones: Gonyleptidae: Pachyloides thorellii)

Male harvestmen penial armature has a remarkable morphology; however, it is poorly known regarding its functions. We examined the male genitalia of virgin and mated males of the gonyleptid Pachyloides thorellii under Scanning Electron Microscope looking for evidence that the penis could remove sperm from the female ovipositor lumen during mating. Micrographs show sperm agglutinations over and within the microsetae fields in six out of the 12 mated males studied. For the mating experiments we used only virgin females, therefore the sperm found in the penis was in all cases their own sperm. This self-sperm removal could be the extraction of sperm excess in cooperation (or not) with the females. This is the first study to show for the Order Opiliones direct evidence that a male penis contains structures that can effectively remove sperm from the female ovipositor. Further behavioral and morphological studies are needed to confirm the conditions of occurrence and participation of each sex in sperm removal processes in this species.

Insights into Notonecta maculata biology and its consumptive and non‐consumptive effects on Aedes albopictus

AbstractNotonecta species (Hemiptera: Notonectidae) are generalist true predators with a strong impact on the size, structure, and richness of the aquatic communities, particularly on mosquito populations. Juvenile and adult backswimmers not only prey on mosquito larvae (consumptive effect) but their presence can also deter the oviposition of gravid mosquito females (non‐consumptive effect). In this study, we selected a Western Palearctic backswimmer, Notonecta maculata Fabricius, as a predator and deterrent of the highly invasive and health‐threatening Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae). In central Italy, N. maculata is univoltine and overwinters in the adult stage. Females lay eggs from February to the end of May, and the first new adults will emerge in late June; the complete nymphal development requires 44.5 ± 3.1 days. The number of Ae. albopictus larvae preyed on by N. maculata during its growth increases while developing, going from 0.03 ± 0.02 larvae per day for first instar nymphs to 21.38 ± 2.90 for mature adults. Furthermore, the presence of a single N. maculata adult in a mosquito ovitrap is enough to discourage the Ae. albopictus oviposition for up to 5 days. Limiting mosquito populations and, consequently, the transmission of viruses and parasites should be our main goal. Therefore, the integrated management of Ae. albopictus by the use of insecticides and a predator (such as backswimmer juveniles and adults), even if only in specific situations, may be promising and feasible. A more in‐depth knowledge of the biological cycle of N. maculata could help, consequently, to optimize its mass rearing.

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 Haemagogus 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: Haemagogus leucocelaenus and Haemagogus janthinomys. 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.

Impact of climate change on the reproductive diapause and voltinism of the carrot weevil, Listronotus oregonensis

The impacts of climate change on the development of insects are of great concern due to potential alterations in population dynamics and pest pressure. The carrot weevil, Listronotus oregonensis, is a major agricultural pest, and its development is influenced by temperature and photoperiod. In this study, our aim was to investigate the impact of temperature increases on the voltinism and reproductive diapause of the carrot weevil under field conditions and bioclimatic models. Field observations were conducted over two growing seasons using structures that allowed for temperature increases. The developmental stages of the carrot weevil, including female reproductive status, oviposition and larval stage, were monitored weekly to measure the proportion of individuals undergoing an additional generation. Concurrently, bioclimatic models were used to simulate the probability of a second generation under current (1981–2010) and future (2041–2070) climates, considering a lower and a higher change in emission scenarios. Results showed that rising temperatures led to an increase in the proportion of carrot weevils undergoing inhibition of the reproductive diapause and a higher number of eggs laid in the field. The models indicated a substantial rise in the probability of a second generation developing, from 24% to 37% to 62%–99% under current and future climates, respectively. These findings demonstrate the potential for significant alterations in carrot weevil population dynamics, resulting in increased pest pressure on crops. Further research is needed to fully understand the implications of these findings and to develop effective adaptation measures to mitigate the negative impacts of global warming on insect populations and agriculture.

Mosquito Egg Raft Distribution Is Affected by Semiochemicals: Indication of Interspecific Competition.

Numerous species of animals alter their behavior in response to increasing competition. To do so, they must possess the ability to detect the presence and density of interspecific competitors. We studied the role of semiochemicals released by increasing densities of larval Culiseta longiareolata Macquart on female oviposition habitat selection in two field experiments. Similarly to C. longiareolata larvae, subordinate Culex laticinctus Edwards are periphyton grazers who dwell in rain-filled pools in the Mediterranean region. We show that C. laticinctus females oviposited significantly less in mesocosm pools that were treated with crowding signals originating from C. longiareolata larvae. In the second experiment, we placed a similar number of larvae directly inside the 50 L mesocosms. These low-density mesocosms did not affect C. laticinctus oviposition but were attractive to conspecific oviposition. These results increase our understanding of the female ability to detect species-specific signals, indicating increased larval competition.

Colonization of Piriformospora indica enhances rice resistance against the brown planthopper Nilaparvata lugens.

Piriformospora indica is an endophytic fungus that can promote the growth and confer resistance against diverse stresses in host plants by root colonization. However, the effects of P. indica colonization on improving plant resistance to insect pests are still less explored. The brown planthopper (BPH) Nilaparvata lugens is a serious monophagous pest that causes extensive damage to rice plants. Here, we aimed to evaluate the effects of P. indica colonization on rice resistance against BPH. The colonization of P. indica in rice roots resisted damage from BPH. Age-stage, two-sex life table analyses showed that feeding on P. indica-colonized rice plants affected BPH's female adult longevity, oviposition period, fecundity, population parameters and population size. BPH female adults feeding on P. indica-colonized plants excreted less honeydew. P. indica colonization remarkably increased the duration of np, N2, and N3 waveform, as well as the occurrences of N1 and N2, and decreased the duration of N4-b for BPH on rice plants. Meanwhile, the weight of BPH on the colonized plants was significantly lower than the control. In addition, the feeding and oviposition preferences of BPH to P. indica-colonized plants were reduced. qRT-RCR analyses revealed that P. indica colonization induced the expressions of jasmonic acid (JA)- and salicylic acid (SA)-related genes in rice plants. P. indica colonization can reduce BPH performance on rice plants with potential inhibitory effects on population growth. Collectively, these results support the potential for endophytically colonized P. indica as an effective strategy to improve insect resistance of crops. © 2024 Society of Chemical Industry.

The Female-Biased General Odorant Binding Protein 2 of Semiothisa cinerearia Displays Binding Affinity for Biologically Active Host Plant Volatiles.

Herbivorous insects rely on volatile chemical cues from host plants to locate food sources and oviposition sites. General odorant binding proteins (GOBPs) are believed to be involved in the detection of host plant volatiles. In the present study, one GOBP gene, ScinGOBP2, was cloned from the antennae of adult Semiothisa cinerearia. Reverse-transcription PCR and real-time quantitative PCR analysis revealed that the expression of ScinGOBP2 was strongly biased towards the female antennae. Fluorescence-based competitive binding assays revealed that 8 of the 27 host plant volatiles, including geranyl acetone, decanal, cis-3-hexenyl n-valerate, cis-3-hexenyl butyrate, 1-nonene, dipentene, α-pinene and β-pinene, bound to ScinGOBP2 (KD = 2.21-14.94 μM). The electrical activities of all eight ScinGOBP2 ligands were confirmed using electroantennography. Furthermore, oviposition preference experiments showed that eight host volatiles, such as decanal, cis-3-hexenyl n-valerate, cis-3-hexenyl butyrate, and α-pinene, had an attractive effect on female S. cinerearia, whereas geranyl acetone, 1-nonene, β-pinene, and dipentene inhibited oviposition in females. Consequently, it can be postulated that ScinGOBP2 may be implicated in the perception of host plant volatiles and that ScinGOBP2 ligands represent significant semiochemicals mediating the interactions between plants and S. cinerearia. This insight could facilitate the development of a chemical ecology-based approach for the management of S. cinerearia.

Girdling behavior of the longhorn beetle modulates the host plant to enhance larval performance

BackgroundPreingestive behavioral modulations of herbivorous insects on the host plant are abundant over insect taxa. Those behaviors are suspected to have functions such as deactivation of host plant defenses, nutrient accumulation, or modulating plant-mediated herbivore interactions. To understand the functional consequence of behavioral modulation of insect herbivore, we studied the girdling behavior of Phytoecia rufiventris Gautier (Lamiinae; Cerambycidae) on its host plant Erigeron annuus L. (Asteraceae) that is performed before endophytic oviposition in the stem.ResultsThe girdling behavior significantly increased the larval performance in both field monitoring and lab experiment. The upper part of the girdled stem exhibited lack of jasmonic acid induction upon larval attack, lowered protease inhibitor activity, and accumulated sugars and amino acids in compared to non-girdled stem. The girdling behavior had no effect on the larval performance of a non-girdling longhorn beetle Agapanthia amurensis, which also feeds on the stem of E. annuus during larval phase. However, the girdling behavior decreased the preference of A. amurensis females for oviposition, which enabled P. rufiventris larvae to avoid competition with A. amurensis larvae.ConclusionsIn conclusion, the girdling behavior modulates plant physiology and morphology to provide a modulated food source for larva and hide it from the competitor. Our study implies that the insect behavior modulations can have multiple functions, providing insights into adaptation of insect behavior in context of plant-herbivore interaction.

The oviposition preference and offspring performance of Aethina tumida (Coleoptera: Nitidulidae).

Given the rapid spread and potential harm caused by the small hive beetle, Aethina tumida (Coleoptera: Nitidulidae) in China, it has become imperative to comprehend the developmental biology of this invasive species. Currently, there is limited knowledge regarding the impact of A. tumida female oviposition site preference on larval growth and development. To examine this, we investigated the ovipositional preference of adult female A. tumida on bee pupae, beebread, banana, and honey through a free choice test. Furthermore, we assessed the impact of these food resources on offspring performance, which included larval development time, survival, wandering larvae weight, emerged adult body mass, reproduction, and juvenile hormone titer. Our results showed that A. tumida females exhibited a strong preference for ovipositing on bee pupae compared to other diets, while showing reluctance toward honey. Moreover, A. tumida larvae that were fed on bee pupae displayed accelerated growth compared to those fed on other diets. Furthermore, A. tumida fed on bee pupae exhibited higher weights for wandering larvae, and emerged adult, increased pupation rates, enhanced fecundity and fertility, as well as a larger number of unilateral ovarioles during the larval stage when compared to those fed on other diets. Overall, the results indicate that the oviposition preferences of A. tumida females are adaptive, as their choices can enhance the fitness of their offspring. This finding aligns broadly with the hypothesis of oviposition preference and larval performance. This study can provide a foundation for the development of attractants aimed at promoting the oviposition of the A. tumida adults.