Entomologia Experimentalis et Applicata最新文献

Plasticity can help populations cope with environmental changes, namely by exploring various ecological niches. Addressing plasticity for nutritional responses in a range of fruit hosts potentially used by Drosophila may be essential in predicting the capacity of insects to colonize new environments or return to ancestral ones. Here, we test for differences in oviposition performance, reproductive success and juvenile viability in diverse host fruits in the colonizing species Drosophila subobscura (Collin 1936, Diptera: Drosophilidae) and compare them with those of the laboratory maintenance medium to which populations adapted for ~150 generations. We question as follows: Does D. subobscura show plasticity associated with various fruit hosts? Is performance better in the long-term maintenance (control) medium? We observed a higher fecundity, reproductive success and juvenile viability of flies maintained in the fruit media versus the control, but no differences between fruits. Our experiment shows that long-term laboratory populations of D. subobscura can still assess environmental cues of new substrates, allowing for flexible adaptive plasticity to occur through increased fecundity and reproductive success in fruit hosts relative to the control conditions. Importantly, this ability was not lost during long-term evolution in a benign, homogeneous environment. Furthermore, the high performance across fruits reinforces its status as a generalist species and further attests to its potential to colonize various ecological settings.

Common gorse, Ulex europaeus L. (Fabaceae) is a serious invasive shrub of pastures, forest gaps, and natural areas in western North America. The seed weevil, Exapion ulicis (Forster) (Coleoptera: Brentidae) was introduced as a biological control organism at three locations in California and one location in Oregon from 1953 through 1956. To document its performance as a biological control organism, a survey of 11 gorse populations along a north–south transect was performed in 2021 and 2022. The seed weevil was recovered at all locations, but the intensity of attack (percentage of pods infested) varied from 2 to 88%. Various components of pod fecundity (pod length, number of ovules, seed set, number of mature and intact seeds) varied spatially. Seed set (mature seed-to-ovule ratio) ranged from 24 to 60% and production of mature seeds (prior to predation) ranged from 1.4 to 4.6 seeds per pod. When present, E. ulicis larvae destroyed 91% of seed in a pod. For infested pods, the number of weevils per mature seed was 1.72, with an average of 6.3 weevils and 3.3 mature seeds per pod. The number of intact seeds after predation averaged 0.3 seeds per pod. Mean seed loss due to E. ulicis ranged from 1 to 81% among locations and was closely related to the local intensity of attack. Oviposition by female E. ulicis targeted more fecund pods. Three parasitoids were recovered, with local parasitization rates of E. ulicis larvae ranging from 0 to 1.6%, suggesting that parasitoids do not limit population abundance of the seed weevil.

The spotted wing drosophila, Drosophila suzukii, is an invasive pest of soft-skinned fruits. The efficacy of pesticides and repellents against this pest has often been evaluated in laboratory bioassays through the use of fresh fruits as a test subject. However, the use of fresh fruits may have several limitations, including variability in their attractiveness, high perishability, and the potential presence of agrochemical residuals. To address these challenges, this study aimed to assess the efficacy of artificial fruits produced from inexpensive, edible, and readily accessible ingredients as oviposition substrates for D. suzukii. Blueberry-grape juice, blueberry-apple juice, raspberry jam, strawberry jam, and D. suzukii solid artificial diet were used as food sources. Artificial fruits prepared with uncolored artificial diet were then colored using three different red edible colorings. Drosophila suzukii females were exposed to all artificial fruits, and the ovipositional responses of the pest were evaluated by counting the total number of eggs laid in food-based substrates. Artificial fruits prepared with artificial diet and colored with red edible colorings were found to be the most attractive substrates to D. suzukii females, exhibiting an average number of eggs up to nine times higher than that of other tested ones. Our findings indicate that artificial fruits represent a viable alternative to fresh fruits for testing the ovipositional responses of D. suzukii under laboratory conditions, thereby facilitating the standardization of fruit-making procedures.

Wing geometric morphometrics is a widely used tool for taxonomic and ecological studies. The conventional method involves killing insects and cutting the wings for preparation on slides and microscope photography. In this work, we proposed an alternative method to avoid killing and wing cutting, using honey bees as model species. We validated three more sustainable practices: using a smartphone to photograph the wings instead of the microscope; analyzing images of wings left attached to the bees; and using live anesthetized bees without sacrificing them. The results of geometric morphometrics and statistical analyses demonstrated the validity of using the smartphone to capture wing images of adequate quality to correctly digitize the landmarks at the veins intersection. Wings left attached to the bees and photographed without any support were significantly different in shape from those cut and taped to a sheet of paper. Probably the position of the wings was not parallel enough to the smartphone, which caused image distortions. This problem was overcome by placing the wings in a homemade portable clamp to flatten them and keep them more parallel to the smartphone. In this way, the morphology of the wings left attached to the bees was equal to that of the cut wings. Lastly, analyses of wing images of anesthetized live bees showed no differences compared with those of cut wings. These results set the basis for the non-destructive application of geometric morphometrics on museum specimens and for field applications on caught and released individuals, avoiding the unnecessary killing of insects.

We report a novel robust method for rearing two species of cynipid gall wasps, Diplolepis mayri (Schlechtendal) and Diplolepis rosae (Linnaeus) (both Hymenoptera: Diplolepididae), under controlled laboratory conditions. This study involved using five wild rose species (Rosa rubiginosa [L.], Rosa canina [L], Rosa gallica [L], Rosa spinosissima [L.], and Rosa arvensis [Huds]; Rosaceae) maintained under artificial lighting with L14:D10 (2023) and L16:D8 (2024) photoperiods, 60%–70% relative humidity, and a constant temperature of 22–23°C. Successful induction, development, and emergence of gall wasps were achieved over two consecutive years. Remarkably, a second generation of D. mayri emerged within the same year, a phenomenon not previously observed in outdoor nor laboratory settings. Our results show that D. mayri may be more suited for laboratory model studies than D. rosae. This technique provides a foundation for future studies on the ecology, evolution, and host–parasite interactions of cynipid wasps.

Mosaic disease, caused by Cassava mosaic virus and transmitted by cassava whitefly, Bemisia tabaci (Gennadius; Hemiptera: Aleyrodidae), is the main threat to cassava production. Various genotypes with various degrees of resistance were employed to study the interactions between the whitefly and virus. These interactions included dispersal, feeding, fecundity, adult longevity and the life cycle. Virus acquisition in whiteflies altered their dispersal and settling behaviour. For the non-viruliferous whiteflies that fed on resistant cassava genotypes, the speed of movement between leaves was higher compared to the viruliferous ones that fed on susceptible genotypes. Viruliferous whiteflies on susceptible genotypes fed more efficiently compared to non-viruliferous ones on resistant genotypes, but fecundity was lowest in viruliferous whiteflies on resistant genotypes. The presence of virus in the system reduced adult longevity but extended the total life cycle. This study provides insights into how the virus modulates the behaviour and physiology/biology of the vector for enhanced transmissibility.

Insects use multiple body parts, not just their mouth, to taste. Whether a particular body part has a taste function can be determined by examining the morphology or electrophysiological response of its sensilla (sense organs) or by its behavioral response. This study investigated the taste response of each of the three pairs of tarsi, tibiae, femurs, as well as the antennae and wings, in house flies, Musca domestica L. (Diptera: Muscidae). This was done by measuring the proboscis extension response (PER), and in the case of the wings, also the grooming behavior. PER is a visible precursor to consumption. The fore, middle, and hind tarsi of both male and female house flies distinguished between sucrose solution versus water. The fore tibiae and femurs of females and the middle femurs of males also made this distinction. Of the body parts tested, the middle, and especially the fore, tarsi were the ones most responsive to sucrose. Contact of aristae (part of the antennae) did not elicit PER regardless of whether contact was with a toothpick that had been soaked in sucrose, water, or nothing. For both males and females, neither the proportion of flies exhibiting PER nor the duration of grooming was significantly affected by whether the anterior wing margin was contacted with a toothpick that had been soaked in sucrose, water, or a dry toothpick.

Brown marmorated stink bug (BMSB), Halyomorpha halys Stal (Hemiptera: Pentatomidae), is a significant invasive agricultural pest affecting diverse crops globally. Halyomorpha halys rapidly invaded the Black Sea agricultural region of Türkiye, necessitating investigation of invasion pathways using complementary molecular approaches. We employed a novel approach on insect genetics—start codon targeted (SCoT) markers—to assess intraspecific genetic diversity among 71 BMSB specimens from 12 Turkish provinces and analyzed mitochondrial cytochrome c oxidase subunit I (COI) regions from nine specimens and integrating previously published data to construct a phylogenetic TCS network. SCoT markers revealed substantial genetic diversity (91.4% polymorphic fragments), identifying six distinct genetic clusters within Turkish populations. Analysis of molecular variance showed significant population structuring at the provincial level but limited differentiation regionally. The Western Black Sea region exhibited highest genetic diversity, with Trabzon identified as a variation hotspot. Conversely, COI-based TCS analysis showed all Turkish specimens belonged exclusively to the dominant Hap_1 lineage prevalent in most invaded countries worldwide. The marker systems highlight improved resolution of SCoT markers in detecting recent genetic diversification not apparent through mitochondrial analysis alone. This novel genetic approach enhances understanding of BMSB invasion pathways in the Black Sea region of Türkiye. Understanding invasion dynamics and genetic variation with worldwide BMSB samples would provide crucial information for developing targeted management measures. Our results demonstrate the potential utility of SCoT markers for detecting intraspecific genetic diversity within regional insect populations. This preliminary assessment, based on 71 specimens for SCoT analysis and nine representative specimens for COI sequencing, provides foundational evidence for the superior resolution of SCoT markers in invasion genetics studies.

Social insects are known to have a complex and elaborate communication system. In termites, communication through chemical signals is paramount, as the soldiers and workers of the majority of species are blind and have cryptic habits. Despite this, knowledge about the role of foraging signals in termites is still scarce, especially in phylogenetically derived species. Here, we aimed to analyze the role of foraging signals in Nasutitermes corniger (Motschulsky, 1855) (Termitidae: Nasutitermitinae), including the effect of various glands and/or caste origins of foraging signals, the response of groups with various caste compositions, and the intercolonial perception of these signals. Specifically, we tested the following hypotheses: (i) rectal fluid and sternal gland extracts have diverse roles in perception, orientation, and acceptance by groups of N. corniger with distinct caste compositions; (ii) the behavior of N. corniger exposed to intercolonial foraging signals is not altered compared with intracolonial signals; and (iii) intercolonial foraging signals attract N. corniger. To do so, trailing behavior and attraction behavior bioassays were carried out in the laboratory. The sternal gland extract triggered the greatest trailing behavior among the foraging signals. Furthermore, the rectal fluid extract seems to elicit trail-following behavior in N. corniger, whereas the sternal gland extract acts as a recruitment signal. Finally, the behavior and attractiveness of the intercolonial foraging signals were not different from that of the intracolonial signals. The results found in the present study increase the understanding of foraging chemical communication in Termitoidae and reveal the role of intercolonial signals in the attractiveness of groups of N. corniger.

Prior damage can alter a plant's susceptibility to future herbivory and yield potential, which is mediated, in part, by the plant's ability to regrow and changes in nutritional content. In perennial sugarcane (Saccharum spp.), herbivory by lepidopteran stem borers early in a growing season can increase the probability of conspecific herbivory later in the crop year. However, it is unknown whether the effects of prior borer damage either to vegetatively propagated seed cane or to standing plants can impact conspecific herbivory or crop yield in subsequent crop years. Using a long-term dataset and two field studies, we investigated the impacts of prior sugarcane borer (SCB; Diatraea saccharalis [F.]; Lepidoptera: Crambidae) damage on levels of conspecific damage across crop years. We also evaluated long-term impacts of SCB damage on plant quantity and quality, aspects that may alter future herbivory and yield. We found that prior SCB damage to either seed cane or standing crops did not alter conspecific damage in subsequent crop years. This prior SCB damage also did not impact plant quality (fiber, sucrose, and carbon content). However, foliar nitrogen was lower in plots without SCB damage in the first year but damaged in the second crop year. Metrics of plant quantity (tiller emergence and aboveground biomass) and total sugar yield were not impacted by prior years' SCB damage. Taken together, our data indicate that although SCB herbivory can significantly increase conspecific herbivory and impact sugarcane plants within a crop year, these effects were not sustained post-harvest following regrowth of aboveground biomass.