Responses Of Insects Research Articles

Identification and Characterization of the CPP Gene Family in the Genome of Aedes aegypti L. (Yellow Fever Mosquito) (Diptera: Culicidae)

Aedes aegypti is an important vector organism responsible for carrying numerous arboviral pathogens and serious diseases, including yellow fever, Zika, Chikungunya, and Dengue fever. The CPP gene family, one of the crucial molecular defense systems, plays a significant role in the regulation of growth and development by controlling the production of proteins. In this study, a comprehensive genome analysis of the CPP gene family in Ae. aegypti was conducted. Each gene was thoroughly characterized, gene structures were examined, and conserved motifs were investigated. Additionally, the properties of these proteins were comprehensively analyzed. Expression analyses were performed to reveal the effects of CPP genes on development by calculating Reads Per Kilobase Million (RPKM) values. The findings emphasize the importance of CPP genes in controlling arboviral pathogens and understanding general stress responses in insects. The information derived from this research could contribute to the development of more effective intervention strategies for Ae. aegypti and other vector carriers to cope with stress. In conclusion, the systematic analysis of the CPP gene family in the Ae. aegypti genome is a crucial step in the management and development of effective disease prevention strategies for this species. Moreover, this study provides a significant foundation for future functional genomics research in understanding the structure and function of CPP genes.

Manipulation of GameXPeptide synthetase gene expression by a promoter exchange alters the virulence of an entomopathogenic bacterium, Photorhabdus temperata temperata, by modulating insect immune responses.

An entomopathogenic bacterium, Photorhabdus temperata subsp. temperata, is mutualistic to its host nematode, Heterorhabditis megidis. The infective juvenile nematodes enter target insects through natural openings and release the symbiotic bacteria into the insect hemocoel. The released bacteria suppress the insect immune responses and cause septicemia through their secondary metabolites. GameXPeptide (GXP) is one of the common secondary metabolites of most Photorhabdus species and is produced by the catalytic activity of a specific non-ribosomal peptide synthetase called GxpS encoded by the gxpS gene. This study confirmed gxpS to be encoded in the P. temperata temperata genome and analyzed its expression during bacterial growth. LC-MS/MS analysis of the bacterial culture broth contained at least four different GXPs (GXP-A to GXP-D), in which GXP-A was the most abundant. To investigate GXP synthesis following gxpS expression, the gxpS promoter of P. temperata temperata was replaced with an inducible arabinose promoter by homologous recombination. The gxpS transcript levels in the mutant were altered by the addition of l-arabinose. Without the inducer, the gxpS transcript level was significantly lower compared to the wild type and produced significantly lower amounts of the four GXPs. The addition of the inducer to the mutant significantly increased gxpS expression and produced significantly higher levels of the four GXPs compared to the wild type. The metabolite extracts obtained from wild-type and mutant bacteria showed differential immunosuppressive activities according to their GXP contents against the cellular and humoral immune responses of a lepidopteran insect, Spodoptera exigua. Interestingly, the gxpS-mutant bacteria showed less insecticidal activity compared to the wild type, whereas the addition of GXP to the mutant significantly restored insecticidal activity. These results suggest that the gxpS gene encoded in P. temperata temperata is responsible for the production of at least four different GXPs, which play crucial roles in bacterial virulence.

If you build it, will they come? Insect community responses to habitat establishment at solar energy facilities in Minnesota, USA

Global declines in insect populations have important implications for biodiversity and food security. To offset these declines, habitat restoration and enhancement in agricultural landscapes could mutually safeguard insect populations and their pollination services for crop production. The expansion of utility-scale solar energy development in agricultural landscapes presents an opportunity for the dual use of the land for energy production and biodiversity conservation through the establishment of grasses and forbs planted among and between the photovoltaic solar arrays (‘solar-pollinator habitat’). We conducted a longitudinal field study across 5 years (2018–2022) to understand how insect communities responded to newly established habitat on solar energy facilities in agricultural landscapes by evaluating (1) temporal changes in flowering plant abundance and diversity; (2) temporal changes in insect abundance and diversity; and (3) the pollination services of solar-pollinator habitat by comparing pollinator visitation to agricultural fields near solar-pollinator habitat with other agricultural field locations. We found increases over time for all habitat and biodiversity metrics: floral rank, flowering plant species richness, insect group diversity, native bee abundance, and total insect abundance, with the most noticeable temporal increases in native bee abundance. We also found positive effects of proximity to solar-pollinator habitat on bee visitation to nearby soybean (Glycine max) fields. Bee visitation to soybean flowers adjacent to solar-pollinator habitat were comparable to bee visitation to soybeans adjacent to grassland areas enrolled in the Conservation Reserve Program, and greater than bee visitation to soybean field interior and roadside soybean flowers. Our observations highlight the relatively rapid (<4 year) insect community responses to grassland restoration activities and provide support for solar-pollinator habitat as a feasible conservation practice to safeguard biodiversity and increase food security in agricultural landscapes.

Low heat tolerance and high desiccation resistance in nocturnal bees and the implications for nocturnal pollination under climate change

Predicting insect responses to climate change is essential for preserving ecosystem services and biodiversity. Due to high daytime temperatures and low humidity levels, nocturnal insects are expected to have lower heat and desiccation tolerance compared to diurnal species. We estimated the lower (CTMin) and upper (CTMax) thermal limits of Megalopta, a group of neotropical, forest-dwelling bees. We calculated warming tolerance (WT) as a metric to assess vulnerability to global warming and measured survival rates during simulated heatwaves and desiccation stress events. We also assessed the impact of body size and reproductive status (ovary area) on bees’ thermal limits. Megalopta displayed lower CTMin, CTMax, and WTs than diurnal bees (stingless bees, orchid bees, and carpenter bees), but exhibited similar mortality during simulated heatwave and higher desiccation tolerance. CTMin increased with increasing body size across all bees but decreased with increasing body size and ovary area in Megalopta, suggesting a reproductive cost or differences in thermal environments. CTMax did not increase with increasing body size or ovary area. These results indicate a greater sensitivity of Megalopta to temperature than humidity and reinforce the idea that nocturnal insects are thermally constrained, which might threaten pollination services in nocturnal contexts during global warming.

Octopamine is involved in TRP-induced thermopreference responses in American cockroach

Insects’ thermoregulatory processes depend on thermosensation and further processing of thermal information in the nervous system. It is commonly known that thermosensation involves thermoreceptors, including members of the TRP receptor family, but the involvement of neurotransmitters in thermoregulatory pathways remains unstudied. We conducted test to determine whether octopamine, a biogenic amine that acts as a neurotransmitter and neurohormone in insects, is involved in TRP-induced thermoregulatory responses in Periplaneta americana. We used capsaicin, an activator of the heat-sensitive TRP channel, Painless, to induce thermoregulatory response in cockroaches. Then, we evaluated the behavioural (thermal preferences and grooming), physiological (heart rate) and biochemical responses of insects to capsaicin, octopamine and phentolamine – octopaminergic receptor blocker. Capsaicin, similar to octopamine, increased cockroaches’ grooming activity and heart rate. Moreover, octopamine level and protein kinase A (PKA) activity significantly increased after capsaicin treatment. Blocking octopaminergic receptors with phentolamine diminished cockroaches’ response to capsaicin – thermoregulatory behaviour, grooming and heart rate were abolished. The results indicate that octopamine is a neurotransmitter secreted in insects after the activation of heat receptors.

How to eliminate pathogen without killing oneself? Immunometabolism of encapsulation and melanization in Drosophila.

Cellular encapsulation associated with melanization is a crucial component of the immune response in insects, particularly against larger pathogens. The infection of a Drosophila larva by parasitoid wasps, like Leptopilina boulardi, is the most extensively studied example. In this case, the encapsulation and melanization of the parasitoid embryo is linked to the activation of plasmatocytes that attach to the surface of the parasitoid. Additionally, the differentiation of lamellocytes that encapsulate the parasitoid, along with crystal cells, is accountable for the melanization process. Encapsulation and melanization lead to the production of toxic molecules that are concentrated in the capsule around the parasitoid and, at the same time, protect the host from this toxic immune response. Thus, cellular encapsulation and melanization represent primarily a metabolic process involving the metabolism of immune cell activation and differentiation, the production of toxic radicals, but also the production of melanin and antioxidants. As such, it has significant implications for host physiology and systemic metabolism. Proper regulation of metabolism within immune cells, as well as at the level of the entire organism, is therefore essential for an efficient immune response and also impacts the health and overall fitness of the organism that survives. The purpose of this "perspective" article is to map what we know about the metabolism of this type of immune response, place it in the context of possible implications for host physiology, and highlight open questions related to the metabolism of this important insect immune response.

Hot topics in butterfly research: Current knowledge and gaps in understanding of the impacts of temperature on butterflies

Abstract As small poikilotherms, insects are largely dependent on their environment for thermoregulation and so are particularly vulnerable to changing temperatures. Butterflies are a well‐studied group often used as models to investigate insect responses to temperature. However, little has been done to synthesise and present this large volume of literature in an accessible format, particularly with reference to knowledge gaps and areas rich in information. Using a systematic mapping method, we synthesised the last 40 years of research on the topic of butterfly responses to temperature. We identified and coded 451 research papers, in which butterfly species were studied 3198 times. We identified taxonomic groups, regions and experimental designs that were well or poorly represented. We found that there was a relatively good balance of representation across butterfly families in relation to the number of species within each family. The tropics were less frequently studied than temperate regions, and there were more studies reporting outcomes on adults than at any other life stage. Finally, in situ studies were more common than ex situ studies. Taken together, the higher representation of certain regions, life stages and approaches could lead to an incomplete understanding of the impacts of temperature on butterflies, potentially resulting in ill‐informed decisions. We make suggestions for how to resolve these discrepancies in representation, including calling for an increased focus on the tropics, the establishment of butterfly monitoring schemes in the global south, a greater focus on the effects of temperature on non‐adult life stages, an increase in experiments investigating fluctuating thermal regimes and the incorporation of more behavioural responses to temperature in future research. Only by addressing these disparities can we gain a complete understanding of how butterflies will respond to climate change.

Role of Mermithid Nematodes in the Management of Agricultural and Household Insect Pests: A review

The increasing challenges associated with using chemicals in managing agricultural and household insect pests has prompted a re-evaluation of previous approaches and the search for new ones as alternatives or supplements to the present management programmes. The introduction and release of bio-agents, like fungi, bacteria, viruses, nematodes, and insects for the control of pests is a novel biological control strategy. Among bio-agents, the role of mermithid nematodes in insect-pest management has been considered. Mermithids are prime candidates for biocontrol of insects due to their adaptability to the life cycle of the host, a high degree of host specificity often limited to one or more species of insects, high reproductive potential, free swimming behavior making dissemination of pre-parasitic stage easy, pathogenic ability and high levels of parasitism. Another useful trait favoring their employability is their non-feeding habit soon after emerging from the host body, making their handling simple. The morphological, physiological, and behavioral responses of host insects are significantly disrupted by mermithid infective juveniles often the J2 stage. Many mermithid infections cause abdominal distortion, discolored cuticle/integument, and a decrease in total fat body content of the host. The parasitism by these nematodes can lead to formation of intersexual conditions in the host insects which also create distortion to endocrine system. Owing to such mechanism of parasitism of mermithids, these nematodes are one the best considerations as bio-control agents.

Leafhoppers as vectors of phytoplasma diseases in Canadian berry crops: a review in the face of climate change

Abstract Climate change has facilitated the introduction, establishment, and movement of invasive species in northern regions, enabling the colonization of previously unsuitable areas. While the responses of insects to these changes have been increasingly studied, our understanding of how such alterations impact trophic interactions still requires further research to make reliable predictions about the spread of diseases in a warming world. Phytoplasmas, a group of obligate parasitic unculturable Mollicutes, primarily rely on leafhoppers (Hemiptera: Cicadellidae) for transmission, spread, and survival. Phytoplasmas are associated with over 600 diseases affecting more than 1,000 plant species, including berries, grapevines, and other small fruits. In North America, diseases such as grapevine yellows, blueberry stunt, and strawberry green petal diseases have been linked to phytoplasma strains transmitted by known leafhopper species. However, the number of phytoplasma diseases has significantly increased in North America over the past decade, suggesting the presence of unidentified vectors or an abundance of leafhopper vectors. This short review provides an overview of the current knowledge on leafhoppers as vectors of phytoplasmas to berries, focusing on the last decade’s research in Canada. This paper also explores the potential implications of climate change on this pathosystem, including the anticipated range expansion of leafhopper species, changes in phytoplasma acquisition and transmission, and the risk of new leafhopper-transmitted plant-pathogen introductions through the arrival of new leafhopper species.

Preference and progeny development of stored product insects in response to grain characteristics of millets

Preference and progeny development of stored product insects in response to grain characteristics of millets

The roles of small RNAs in rice-brown planthopper interactions

Interactions between rice plants (Oryza sativa L.) and brown planthoppers (Nilaparvata lugens Stål, BPHs) are used as a model system to study the molecular mechanisms underlying plant-insect interactions. Small RNAs (sRNAs) regulate growth, development, immunity, and environmental responses in eukaryotic organisms, including plants and insects. Recent research suggests that sRNAs play significant roles in rice-BPH interactions by mediating post-transcriptional gene silencing. The focus of this review is to explore the roles of sRNAs in rice-BPH interactions and to highlight recent research progress in unraveling the mechanism of cross-kingdom RNA interference (ckRNAi) between host plants and insects and the application of ckRNAi in pest management of crops including rice. The research summarized here will aid in the development of safe and effective BPH control strategies.

BmPxt1 mediated immune response by regulating PGE2 in silkworm, Bombyx mori

Prostaglandins (PGs) mediates the immune response of insects to multiple stimuli. Mammalian cyclooxygenase (COXs) is a key enzyme in the synthesis of PGs, and peroxinectin (Pxt) may have similar functions in some sequenced insect genomes. As a representative of Lepidoptera, the silkworm also contains PGs, but its synthetic pathway is not clear. We cloned a full-length cDNA encoding a Pxt, designated as BmPxt1, from silkworm. Sequence alignment analysis showed that the protein encoded by BmPxt1 has a conserved domain similar to Pxts, and its catalytic site is shared with the Pxt of Manduca sexta, which also produces PGs. The expression of BmPxt1 gene was the highest in the hemocytes and was induced by Nuclear Polyhedrosis Virus (NPV) challenge in the detected tissues. Moreover, we found that dsPxt1 treatment deficiency down-regulated BmPxt1 transcript levels and efficiently inhibiting hemocyte-spreading and nodule formation in silkworm. Hemocyte-spreading, nodule formation, phenoloxidase (PO) and AMP genes (attacin, defencin and moricin) were also inhibited by aspirin, a COX inhibitor. Treatment by PGE2 but not arachidonic acid (AA) rescued the immunosuppression; PGs concentrations was also inhibited by aspirin. PGE2, but not AA, treatment rescued the PGs concentrations. The COX inhibitor, aspirin, impaired the innate immune response including nodulation, encapsulation, and melanization in silkworm, while PGE2, but not arachidonic acid (AA), partially reversed these effects of aspirin. Recombinant BmsPxt1 significantly induced PO activation in larvae hemolymph, PGs concentrations and encapsulation of agarose beads. Injection of recombinant BmsPxt1 into larvae resulted in increased transcript levels of AMP genes. Our results confirmed that BmPxt1 was involved in the synthesis of PGs in the innate immune response of silkworm larvae, and provided new information for the role of BmsPxt1 secreted by silkworm in activating PO and antimicrobial peptides.

The immunostimulatory role of an Enterococcus-dominated gut microbiota in host protection against bacterial and fungal pathogens in Galleria mellonella larvae.

Understanding the intricate interplay between the gut microbiota and the immune response in insects is crucial, given its diverse impact on the pathogenesis of various microbial species. The microbiota's modulation of the host immune system is one such mechanism, although its complete impact on immune responses remains elusive. This study investigated the tripartite interaction between the gut microbiota, pathogens, and the host's response in Galleria mellonella larvae reared under axenic (sterile) and conventional (non-sterile) conditions. The influence of the microbiota on host fitness during infections was evaluated via two different routes: oral infection induced by Bacillus thuringiensis subsp. galleriae (Btg), and topical infection induced by Metarhizium robertsii (Mr). We observed that larvae without a microbiota can successfully fulfill their life cycle, albeit with more variation in their developmental time. We subsequently performed survival assays on final-instar larvae, using the median lethal dose (LD50) of Btg and Mr. Our findings indicated that axenic larvae were more vulnerable to an oral infection of Btg; specifically, a dose that was calculated to be half-lethal for the conventional group resulted in a 90%-100% mortality rate in the axenic group. Through a dual-analysis experimental design, we could identify the status of the gut microbiota using 16S rRNA sequencing and assess the level of immune-related gene expression in the same group of larvae at basal conditions and during infection. This analysis revealed that the microbiota of our conventionally reared population was dominated entirely by four Enterococcus species, and these species potentially stimulated the immune response in the gut, due to the increased basal expression of two antimicrobial peptides (AMPs)-gallerimycin and gloverin-in the conventional larvae compared with the axenic larvae. Furthermore, Enterococcus mundtii, isolated from the gut of conventional larvae, showed inhibition activity against Btg in vitro. Lastly, other immune effectors, namely, phenoloxidase activity in the hemolymph and total reactive oxygen/nitrogen species (ROS/RNS) in the gut, were tested to further investigate the extent of the stimulation of the microbiota on the immune response. These findings highlight the immune-modulatory role of the Enterococcus-dominated gut microbiota, an increasingly reported microbiota assemblage of laboratory populations of Lepidoptera, and its influence on the host's response to oral and topical infections.

Temperature Sensitivity of Fitness Components across Life Cycles Drives Insect Responses to Climate Change.

AbstractThermal performance curves (TPCs) are increasingly used as a convenient approach to predict climate change impacts on ectotherms that accounts for organismal thermal sensitivity; however, directly applying TPCs to temperature data to estimate fitness has yielded contrasting predictions depending on assumptions regarding climate variability. We compare direct application of TPCs to an approach integrating TPCs for different fitness components (e.g., per capita birth rate, adult life span) across ectotherm life cycles into a population dynamic model, which we independently validated with census data and applied to hemipteran insect populations across latitude. The population model predicted that climate change will reduce insect fitness more at higher latitudes due to its effects on survival but will reduce net reproductive rate more at lower latitudes due to its effects on fecundity. Directly applying TPCs underestimated climate change impacts on fitness relative to incorporating the TPCs into the population model due to simplifying survival dynamics across the life cycle. The population model predicted that climate change will reduce mean insect density and increase population variability at higher latitudes via reduced survival, despite faster development and a longer activity period. Our study highlights the importance of considering how multiple fitness components respond to climate variability across the life cycle to better understand and anticipate the ecological consequence of climate change.

Serpin-1a and serpin-6 regulate the Toll pathway immune homeostasis by synergistically inhibiting the Spätzle-processing enzyme CLIP2 in silkworm, Bombyx mori.

The Toll receptor signaling pathway is an important innate immune response of insects to pathogen infection; its extracellular signal transduction involves serine protease cascade activation. However, excessive or constitutive activation of the Toll pathway can be detrimental. Hence, the balance between activation and inhibition of the extracellular protease cascade must be tightly regulated to achieve favorable outcomes. Previous studies have shown that serpins-serine protease inhibitors-negatively regulate insect innate immunity by inhibiting extracellular protease cascade signaling. Although the roles of serpins in insect innate immunity are well described, the physiological mechanisms underlying their synergistic effects remain poorly understand. Here, we characterize the molecular mechanism by which serpin-1a and serpin-6 synergistically maintain immune homeostasis of the silkworm Toll pathway under physiological and pathological conditions. Through in vitro biochemical assays and in vivo bioassays, we demonstrate that clip-domain serine protease 2 (CLIP2), as the Toll cascade-activating terminal protease, is responsible for processing proSpätzle1 to induce the expression of antimicrobial peptides. Further biochemical and genetic analyses indicate that constitutively expressed serpin-1a and inducible serpin-6 synergistically target CLIP2 to maintain homeostasis of the silkworm Toll pathway under physiological and pathological conditions. Taken together, this study provides new insights into the precise regulation of Toll cascade activation signals in insect innate immune responses and highlights the importance and complexity of insect immune homeostasis regulation.

Behavioral responses of free-flying Drosophila melanogaster to shiny, reflecting surfaces

Active locomotion plays an important role in the life of many animals, permitting them to explore the environment, find vital resources, and escape predators. Most insect species rely on a combination of visual cues such as celestial bodies, landmarks, or linearly polarized light to navigate or orient themselves in their surroundings. In nature, linearly polarized light can arise either from atmospheric scattering or from reflections off shiny non-metallic surfaces like water. Multiple reports have described different behavioral responses of various insects to such shiny surfaces. Our goal was to test whether free-flying Drosophila melanogaster, a molecular genetic model organism and behavioral generalist, also manifests specific behavioral responses when confronted with such polarized reflections. Fruit flies were placed in a custom-built arena with controlled environmental parameters (temperature, humidity, and light intensity). Flight detections and landings were quantified for three different stimuli: a diffusely reflecting matt plate, a small patch of shiny acetate film, and real water. We compared hydrated and dehydrated fly populations, since the state of hydration may change the motivation of flies to seek or avoid water. Our analysis reveals for the first time that flying fruit flies indeed use vision to avoid flying over shiny surfaces.

Time-series analysis of transcriptomic changes due to permethrin exposure reveals that Aedes aegypti undergoes detoxification metabolism over 24 h

Insecticide resistance is a multifaceted response and an issue across taxa. Aedes aegypti, the mosquito that vectors Zika, dengue, chikungunya, and yellow fever, demonstrates high levels of pyrethroid resistance across the globe, presenting a challenge to public health officials. To examine the transcriptomic shifts across time after exposure to permethrin, a 3’Tag-Seq analysis was employed on samples 6, 10, and 24 h after exposure along with controls. Differential expression analysis revealed significant shifts in detoxifying enzymes and various energy-producing metabolic processes. These findings indicate significant alterations in gene expression associated with key energy mobilization pathways within the system. These changes encompass a coordinated response involving lipolysis, beta-oxidation, and the citric acid cycle, required for the production of energetic molecules such as ATP, NADH, NADPH, and FADH. These findings highlight a complex interplay of metabolic processes that may have broader implications for understanding insect physiology and response to environmental stimuli. Among the upregulated detoxifying enzymes are cytochrome P450s, glutathione s-transferases and peroxidases, and ATP-binding cassette transporters. Additionally, eight heat shock genes or genes with heat shock domains exhibit the highest fold change across time. Twenty-four hours after exposure, samples indicate a global downregulation of these processes, though principal component analysis suggests lasting signatures of the response. Understanding the recovery response to insecticide exposure provides information on possible new genetic and synergist targets to explore.

Post-Mating Responses in Insects Induced by Seminal Fluid Proteins and Octopamine.

Following insect mating, females often exhibit a series of physiological, behavioral, and gene expression changes. These post-mating responses (PMRs) are induced by seminal fluid components other than sperm, which not only form network proteins to assist sperm localization, supplement female-specific protein requirements, and facilitate the formation of specialized functional structures, but also activate neuronal signaling pathways in insects. This review primarily discusses the roles of seminal fluid proteins (SFPs) and octopamine (OA) in various PMRs in insects. It explores the regulatory mechanisms and mediation conditions by which they trigger PMRs, along with the series of gene expression differences they induce. Insect PMRs involve a transition from protein signaling to neuronal signaling, ultimately manifested through neural regulation and gene expression. The intricate signaling network formed as a result significantly influences female behavior and organ function, contributing to both successful reproduction and the outcomes of sexual conflict.

Chemodiversity in flowers of Tanacetum vulgare has consequences on a florivorous beetle.

The chemical composition of plant individuals can vary, leading to high intraspecific chemodiversity. Diversity of floral chemistry may impact the responses of flower-feeding insects. Tanacetum vulgare plants vary significantly in their leaf terpenoid composition, forming distinct chemotypes. We investigated the composition of terpenoids and nutrients of flower heads and pollen in plants belonging to three chemotypes - dominated either by β-thujone (BThu), artemisia ketone (Keto) or a mixture of (Z)-myroxide, santolina triene, and artemisyl acetate (Myrox) - using different analytical platforms. We tested the effects of these differences on preferences, weight gain and performance of adults of the shining flower beetle, Olibrus aeneus. The terpenoid composition and diversity of flower heads and pollen significantly differed among individuals belonging to the above chemotypes, while total concentrations of pollen terpenoids, sugars, amino acids, and lipids did not differ. Beetles preferred BThu over the Myrox chemotype in both olfactory and contact choice assays, while the Keto chemotype was marginally repellent according to olfactory assays. The beetles gained the least weight within 48 h and their initial mortality was highest when feeding exclusively on floral tissues of the Myrox chemotype. Short-term weight gain and long-term performance were highest when feeding on the BThu chemotype. In conclusion, the beetles showed chemotype-specific responses towards different T.vulgare chemotypes, which may be attributed to the terpenoid composition in flower heads and pollen rather than to differences in nutrient profiles. Both richness and overall diversity are important factors when determining chemodiversity of individual plants and their consequences on interacting insects.

Isolation of the AccCDK8 gene of Apis cerana cerana and its functional analysis under pesticide and heavy metal stress

Environmental pollution has gained negative attention in recent years. The pesticides and heavy metals are top list of environmental toxicants directly endangering the survival and development of Apis cerana cerana. Cyclin-dependent kinases (CDKs) are heteromeric serine/threonine kinases that participate in cell cycle regulation and have a vital role in pesticide and heavy metal stress in Apis cerana cerana. In this experiment, we filtered out CDK8 gene from Apis cerana cerana (AccCDK8) and investigated its functions of pesticide and heavy metals resistance. Sequence analysis indicated that AccCDK8 is highly homologous to multiple CDK8s and contains a highly conserved CDK active site sequence. Phylogenetic analysis showed that AmCDK8 and AccCDK8 were closely related evolutionarily in Apis mellifera. Transcriptome analysis revealed that AccCDK8 expression was differentially affected after exposure to pesticide and heavy metal stresses. This indicates that AccCDK8 has a significant role in the resistance of Apis cerana cerana to pesticide and heavy metal stresses. It has implications for studying the function of CDK in other insects in response to stress.