Insect Activity Research Articles

Validation of selective catalytic BmCBP inhibitors that regulate the Bm30K-24 protein expression in silkworm, Bombyx mori.

The cAMP response element binding protein (CREB)-binding protein (CBP) is a histone acetyltransferase that plays an indispensable role in regulating the acetylation of histone and non-histone proteins. Recently, it has been discovered that chemical inhibitors A485 and C646 can bind to Bombyx mori's CBP (BmCBP) and inhibit its acetyltransferase activity. Notably, the binding ability of A485 with BmCBP showed a very low Kd value of 48 nM by surface plasmon resonance (SPR) test. Further identification showed that both A485 and C646 can decrease the acetylation level of known substrate H3K27 and only 1 μM of A485 can almost completely inhibit the acetylation of H3K27, suggesting that A485 is an effective inhibitor of BmCBP's acetyltransferase activity. Moreover, it was confirmed that A485 could downregulate the expression of acetylated Bm30K-24 protein at a post-translational level through acetylation modification by BmCBP. Additionally, it was found that A485 can downregulate the stability of Bm30K-24 and improve its ubiquitination level, suggesting that the acetylation modification by BmCBP could compete with ubiquitination modification at the same lysine site on Bm30K-24, thereby affecting its protein stability. Here, we predict that A485 may be a potent CBP acetyltransferase inhibitor which could be utilized to inhibit acetyltransferase activity in insects, including silkworms.

Anti-Diabetic Activity of Cordyceps-Fermented Edible Insects by the Promotion of Glucose Absorption.

Insects are considered important food resources for future diet due to diverse nutrients and pharmacological effects. Fermentation is an important strategy of food processing with various beneficial effects such as increasing nutrients, promoting bioavailability, and reducing anti-nutrients. Cordyceps is a mushroom that grows on insects and produces various active ingredients. Therefore, we investigated the effect of Cordyceps-fermentation of insects on the nutritional composition and functional benefits of the insects. Six edible insects: Bombyx mori, Protaetia brevitarsis, Caelifera, Gryllus bimaculatus, Tenebrio molitor, and Allomyrina dichotoma were fermented with Cordyceps militaris to produce mycelia and fruiting bodies. Analysis of nutritional components showed that protein content was increased whereas carbohydrate content was decreased by the fermentation with Cordyceps. In addition, the fermented insects showed anti-diabetic efficacy by the promotion of glucose absorption as evaluated using differentiated L6-GLUT4myc cells. Quantitation using HPLC analysis suggested that cordycepin was produced in both mycelium and fruiting bodies in Cordyceps-fermented edible insects with different amounts depending on insect type and cultivation conditions. Therefore, the fermentation of insects with Cordyceps is expected to increase nutritional values and bioactive constituents and exert anti-diabetic effects.

Multi-method approach to assessing the floral-visiting insect assemblage of rare, abophilous plant Baccharis vanessae in Southern California.

Insects are the major pollination vectors for angiosperms, and insects native to a given habitat can play an irreplaceable ecological role in food webs and plant reproduction. With precipitous declines in insect species over the last decades, it is urgent to document insect assemblages in native plant communities to support conservation efforts. Identifying pollinators and their pollination activity is challenging; however, emerging technological methods are providing new monitoring capabilities. In this study, we compare the accuracy of two different methods of monitoring to assess the flower-visiting insect assemblage and likely pollinators of Encinitas baccharis (Baccharis vanessae): focal observations and video recordings from camera traps. B. vanessae is a rare, endemic species found in Coastal Sage Scrub communities in San Diego County. This federally listed species is threatened by habitat loss and fragmentation, which may also be affecting the availability of its insect pollinators. Results indicate that B. vanessae supports and is supported by a variety of flower-visiting insect groups. The diversity of insect visitors at male and female plants were similar across all diversity measurements. The insect vectors identified were as expected given B. vanessae pollination syndrome. This syndrome also aligns with wind as a pollination vector, providing evidence of ambophily. While focal observations underreported insect activity by approximately half, the proportions of common diurnal visitors were similar with both methods. Camera traps were unable to provide sufficient detail to discern visually similar groups, but were able to record nocturnal insect activity, which was dominated by moths (Lepidoptera, 82%). While collection protocol in this study did not record the time an insect spent interacting with a flower, we anecdotally observed moths spent notably longer periods in contact with flowers than most diurnal insects. This study has implications for effective monitoring and conservation of endangered plant species and their affiliated pollinators.

Detection of Active Infestation by Wood-Boring Insects via Acoustic Emission using the IADS (Insect Activity Detection System)

The preservation of wooden art and cultural artifacts is severely threatened by the infestation of wood-boring insects. Distinguishing between active and inactive infestations in practice poses a significant challenge, often leading to unnecessary treatments or delayed actions. This article focuses on the examination of the Insect Activity Detection System (IADS), an innovative AE measurement device for the detection of feeding noises of wood-boring larvae. Starting with an overview of the theoretical framework, the results of practical experiments are shown. Finally, we will present some possible applications of IADS in the conservation of art and cultural heritage.

New Methods and Challenges for IPM in Archives, Modern and Historic Libraries

ABSTRACT In this article the most important aspects of IPM, new challenges like climate change, new pests and updated methods of detection are presented. The grey silverfish has already resulted in many problems in archives and libraries across Europe. To set priorities and evaluate a large storage building with many rooms, we present a pest index for detecting high infestation rates and hotspots in the building. For the biscuit beetle we present two new detection methods: The use of a scent detecting (or sniffing) dog trained to detect the larvae of the beetle and the Insect Activity Detection System (IADS), a new technology that uses the acoustical emissions of the larvae feeding on the material. The last aspect of this paper is climate change: in the future higher temperatures, extreme weather events and introduced species will be new challenges for libraries and archives.

Floral biology and breeding behaviour of Melia azedarach L.: imperative for hybridization

Abstract Melia azedarach L. commonly called Maha Neem is an economically and industrially important tree species with global significance. Although species possess versatile importance worldwide, information on reproductive biology and breeding system is scarce and limited for eastern coastal plain of India. Therefore, current study provides a detailed report on reproductive biology of M. azedarach. Maha Neem was found to bear violet to whitish violet, slightly fragrant, 14.99 ± 0.05 mm. long and 17.01 ± 0.08 mm. wide flowers. This tree commenced opening of floral buds during March and continued until May with a peak during March-end. The anthesis of species peaked between 08:00 and 10:00 am, which coincides with insect activity. Anthers were observed to dehisce during or shortly before anthesis; however, stigma started receptivity before anthesis and continued invitation up to 12 h after anthesis. Pollen viability ranged from 96.67 ± 1.6% to 98.26 ± 1.2 at the time of anthesis; after that decreased rapidly. Pollen: ovule ratio of 1096.38 ± 108.70 indicated the possibility of autogamy. The breeding system of M. azedarach revealed that fruit sets under natural pollination (NP) were significantly higher than Xenogamy. However, substantial difference was not reported in fruit set percentage under natural pollination and Autogamy, which is strong evidence in favour of self-pollination. Moreover, Maha-Neem is entomophilous with frequent visits by Apis and Syrphid flies. Current findings will be helpful in designing potent conservation strategies and planning successful breeding programmes.

Impact of ante-mortem fluoxetine administration on estimation of post-mortem interval and insect activity in rabbit carcasses

BackgroundIncreasing the number of drug-related deaths has affected medico-legal death investigations. Drugs within a corpse have a great impact on the insects’ development rate which in turn will affect the rate of post-mortem decomposition and the estimation of the post-mortem interval. This explains the importance of the application of forensic entomotoxicology, which studies the impact of drugs and toxins on the development and succession patterns of insects. The current study aimed to determine the impact of fluoxetine, one of the selective serotonin reuptake inhibitors (SSRIs), on post-mortem decomposition, insects’ attraction, and its pattern of succession on carcasses. Sixteen healthy male and female Oryctolagus cuniculus rabbits were chosen to be included in this study. They were divided into a treated group of eight rabbits received oral fluoxetine for 28 days and a control group of eight rabbits received oral distilled water for 28 days. After oral administration of 10 mg/kg/day of fluoxetine and distilled water for 28 days, rabbits were sacrificed, and carcasses were transmitted to the roof of Research and Training Centre on Vectors of Diseases at faculty of Sciences, Ain Shams University, for following up the post-mortem decomposition process and insect’s attraction to carcasses for 60 days. Carcasses were put in two outdoor sites that differ in temperature to assess the effect of temperature on decomposition process.ResultsFluoxetine administration has accelerated the rate of post-mortem decomposition in the treated carcasses by 3–9 days compared to the control ones and affected the numbers and species of attracted insects, while it had no effect on the insects’ succession patterns. Exposure of carcasses to direct sunlight has accelerated the rate of decomposition in comparison to that of carcasses put in shade in the overall period of decomposition by about 14 to 16 days.ConclusionsFluoxetine has an important and effective role in post-mortem decomposition and estimation of post-mortem interval (PMI) and has a great impact on attracted insects to the treated carcasses. Temperature has a great effect on the rate of decomposition of carcasses. Higher temperature accelerates the rate of post-mortem decomposition.

Influence of Insecticide Application on Pollinators and Predatory Arthropods in Watermelon Agroecosystem

This study, conducted from January to April 2021 in Kandavara village, Karnataka, examined the effects of various insecticides on honeybees, spiders, and coccinellids in watermelon crops. Using a randomized complete block design, watermelon plants were treated with insecticides when pest populations reached economic thresholds. Honeybee foraging activity and populations of spiders and coccinellids were monitored before treatment and at 3,7 and 10 days post-application. Results showed that untreated control plots consistently had the highest activity of all beneficial insects. Among the insecticides tested, Spinosad 45 SC was the least harmful, with relatively higher levels of honeybee and natural enemy activity. In contrast, Imidacloprid 17.8 SL and Acephate 75 SP were the most detrimental, resulting in significantly lower activity levels for honeybees, spiders, and coccinellids. These findings highlight the importance of selecting insecticides that minimize harm to beneficial insects, emphasizing the need for integrated pest management practices that balance effective pest control with the preservation of essential ecosystem services.

Utility of Parthenocarpy in Vegetable Crops: A Review

Parthenocarpy is a phenomenon observed in vegetable crops where fruits are produced without fertilization or pollination. This process leads to the development of seedless fruits, which are highly desirable in the market due to their convenience and improved quality. In parthenocarpic vegetables such as cucumbers, tomatoes and eggplants, fruit development occurs without the need for pollination by insects or wind. This can be advantageous in areas with limited insect activity or in greenhouses where pollinators may not be present. The development of parthenocarpy in vegetable crops is influenced by both genetic and environmental factors. Certain cultivars have been bred to exhibit this trait, while others may require specific environmental conditions such as temperature and light to induce parthenocarpy. One of the key benefits of parthenocarpy is the production of seedless fruits. This is particularly important in seedless cucumber varieties as it eliminates the need for seed removal, making them more convenient for consumption. Seedless tomatoes and eggplants also offer improved texture and taste as the absence of seeds reduces bitterness and enhances sweetness. Parthenocarpy can help improve crop yields and reduce crop losses. Since parthenocarpic fruits develop without pollination, they are less prone to damage caused by pests and diseases that target developing seeds. This can result in higher yields and better overall crop quality. However, it is important to note that parthenocarpy may have some limitations. In some cases, seedless fruits may be less flavorful compared to their seeded counterparts. Additionally, parthenocarpic varieties may require specific management practices and careful monitoring to ensure optimal fruit development.

Barometric pressure decrease induces density-dependent changes in foraging behaviour in a parasitoid fly.

Barometric pressure is an environmental factor involved in the modulation of a variety of activities in insects. Generally, a drop in barometric pressure precedes the arrival of weather conditions that can affect insect activities and life expectancy. We simulated different scenarios of pressure drop in a modified hermetic chamber and studied their influence on the host-seeking behaviour of the larvae of the robber fly Mallophora ruficauda using air stationary olfactometers. In addition, we studied whether larval density modulates orientation to the host under the same scenarios of pressure drop. We found that motivation to search for hosts is affected by the same slope of pressure drop in both low- and high-density larvae. However, larval density modulates the onset of the responses to pressure decrease, as low-density larvae stop searching for hosts more quickly than high-density larvae. This result reflects an avoidance strategy according to which low-density larvae would have a reduced host range and higher risk of mortality and fewer chances to find a suitable host under adverse pressure conditions. Low-density larvae, known to prefer healthy hosts, do not search for parasitized hosts under normal pressure conditions nor under a range of pressure drops, strongly suggesting that host selectivity is not modulated by barometric pressure. This study paves the way to a better understanding of the changes in crucial insect behaviours induced by weather conditions, and provides more knowledge about the risk factors likely to affect insect survival in the context of foraging ecology.

Entomological Abundance and Difference in Insect Activity in Various Crime Scene Conditions

Entomological Abundance and Difference in Insect Activity in Various Crime Scene Conditions

Synchronised monitoring of plant and insect diversity: a case study using automated Malaise traps and DNA-based methods.

The occurrence and distribution of insects and their possible associations with plant species are largely unknown in Germany and baseline data to monitor future trends are urgently needed. Using newly-designed automated Malaise trap multi-samplers, the occurrence of insect species and their potential associations with plants was monitored synchronously at two contrasting field sites in Germany: an urban botanical garden and a forest research station. Taxa were identified by metabarcoding of the insects and the plant traces present in the preservative ethanol of the Malaise trap samples. For comparison, a botanical survey was conducted in the vicinity of the traps. Across both sites, we identified a total of 1290 exact sequence variants (ESVs) assigned to Insecta, of which 205 are known to be pollinators. In the botanical garden, we detected the occurrence of 128 plant taxa, of which 41 also had one of their known insect pollinator species detected. Insect species richness was highest in May, mainly attributed to an increase in Diptera. These results present a case study of the applicability of automated sampling and DNA-based methods to monitor the timings of flowering and corresponding activity of plant-visiting insects.

Expression and Functional Characterization of Oryzacystatin II Protein from Oryza sativa L. Indica Rice and Its Potential Role as a Bioinsecticide Against Major Insects of Rice.

Rice (Oryza sativaL.) is a crucial staple food crop globally, facing significant challenges from various pests that affect crop productivity and quality. Conventional pesticide usage has limitations, necessitating the development of sustainable pest management strategies. This study focuses on the expression, purification, and functional characterization of Oryzacystatin II (OC-II), a protein derived from O. sativaL. Indica rice, with the intent to evaluate its potential as a bioinsecticide against rice pests. The OC-II gene was expressed and purified, and purification confirmed its molecular weight (∼12 kDa) and protein sequence through LC-MS/MS analysis and Western blotting. The IC50 value of OC-II was calculated as 0.06 μM, and the inhibition was identified as a competitive inhibition. The protein exhibited efficient control of both pests at the nymph and adult stages, with lower probing marks observed on treated plants. The inhibition of cathepsin B enzyme activity in insects further confirmed the bioactivity of the OC-II protein. Molecular docking and molecular dynamics simulations provided insights into the interaction between the OC-II protein and cathepsin enzymes reported in BPH and WBPH. Further investigations can focus on optimizing production methods and exploring the specificity and efficacy of the OC-II protein against other crop pests to enhance its practical applications.

Understanding Insect Behavior and Physiology for Effective Pest Management

Effective pest management is crucial for sustainable agriculture and public health, necessitating a deep understanding of insect behavior and physiology. This paper explores the intricate mechanisms that govern insect activities and their interactions with the environment, which are pivotal in developing targeted and efficient pest control strategies. By delving into the sensory and neural processes that drive insect behavior, we uncover how insects locate food, mates, and habitats, providing insights into disrupting these processes to control pest populations. Additionally, the study examines the physiological adaptations that enable insects to thrive under various environmental conditions, such as resistance to pesticides and adaptation to climate changes. Understanding these adaptations is essential for designing novel, more sustainable pest management techniques. The paper also discusses the role of chemical ecology in pest management, focusing on pheromones and other semiochemicals used in integrated pest management (IPM) programs. By combining behavioral studies with physiological research, this paper aims to highlight the synergy between these fields, offering a comprehensive approach to developing innovative and effective pest control methods. The ultimate goal is to contribute to the advancement of pest management practices that are not only effective but also environmentally sustainable and economically viable.

Identification and Functional Characterization of an Odorant Receptor Expressed in the Genitalia of Helicoverpa armigera

Olfaction is critical for guiding the physiological activities of insects, with antennae being the primary olfactory organs. However, recent evidence suggests that other tissues may also participate in olfactory recognition. Among these, the genitalia of moths have received attention due to their roles in mating and oviposition. Sensilla and odorant receptors (ORs) in moth genitalia highlight the potential olfactory function of these structures. In this study, we examined the olfactory sensing capacity of the genitalia in Helicoverpa armigera by analyzing their structure in males and females and characterizing the expressed ORs. Scanning electron microscopy uncovered many sensilla distributed throughout the male and female genitalia. Transcriptome sequencing identified 20 ORs in the genitalia, with HarmOR68 exhibiting significant responses to methyl esters: methyl benzoate and salicylate. Our findings provide theoretical evidence that H. armigera genitalia may have significant olfactory perception functions.

Hydrolandscape Method of territory Zoning: Concept and Application Experience

The paper describes the method and algorithm for creating the sketch-maps of hydrolandscapes to solve practical tasks of forecasting and controlling the number of mass species of blood-sucking insects such as gadflies and mosquitoes. The hydrolandscape method consists in dividing the regions into zones by content, distribution and conservation of moisture as the most important ecosystemic component. The method evaluates the influence of insufficient or excessive moisture content on the life activity of amphibiotic insects. Landscapes similar by moisture content, relief, mesoclimate, soils, vegetation and groups of blood-sucking insects are combined into hydrolandscapes. This method has been applied for different regions of the North-West of Russia (the Novgorod, Leningrad and Pskov Regions), as well as for the Komi Republic. The paper illustrates this experience. Using the hydrolandscape method, the specialists can forecast the species composition and relative abundance of blood-sucking insects in remote areas before they get developed by humans.

Pollination services in the North China Plain measured using buckwheat sentinel plants; is there a deficit?

The transition of food systems for healthy diets and sustainable food systems calls for greater production of fruit and nuts, i.e. pollinated crops. The North China Plain (NCP) is a cereal dominated area that needs to transition to a more sustainable food system with a nutritionally more diverse output. Buckwheat pairs high nutritional quality with low input requirement, but it is pollination dependent. There is little knowledge on the pollinator communities and pollination service in the NCP. We selected Quzhou county as a study region on the NCP, and used potted plants of buckwheat (Fagopyrum esculentum M.) to measure pollination in three treatments: insect exclusion, open pollination, and honeybee supplementation. Measurements were made at 24 sites across the county in 2021 and 2022. At each site, we directly observed the activity of flower-visiting insects and measured the pollination rate, seed set, seed abortion rate and yield-related indicators. Most flower visits were made by hoverflies (Syrphidae) and flies from the families Muscidae, Sarcophagidae, and Calliphoridae. Compared with open pollination, insect exclusion reduced buckwheat pollination rate and seed set by more than 90 %. Without honeybee supplementation, the pollination rate in different experimental sessions was reduced by 12–21 %, and the seed set was reduced by 22–33 %. Honeybee supplementation increased harvest index and seed weight per plant with factors of 1.6 and 2.0, respectively. Hence, a pollination deficit would exist if only natural pollinators were relied upon. Managed honeybees provide an efficient means for enhancing pollination of buckwheat in the North China Plain.

The allatotropin/orexin system as an example of immunomodulatory properties of neuropeptides

The central nervous system (CNS) plays a critical role in signal integration in animals and allows the orchestration of life processes to maintain homeostasis. Current research clearly shows that inflammatory processes can also be modulated by the CNS via the neuroendocrine system. One of the neuropeptide families that participate in vertebrates in this process is orexins (OXs). Interestingly, our previous results suggested that a similar dependency may also exist between neuropeptides and immune system activity in insects. Due to the structural homology of orexin and allatotropin receptors and the functional similarity between these two neuropeptide families, the main aim of this research was to perform a complex analysis of the relationships between allatotropin (AT) and the insect immune response. Our results revealed functional similarities between vertebrate OXs and insect ATs. Similar effects were observed in the profile of the expression level of the gene encoding the AT precursor in the Tenebrio molitor nervous system and in the general action of Tenmo-AT on selected immune parameters of the tested beetles. Moreover, for the first time in insects, we confirmed the role of cytokines in the modulation of neuroendocrine system by determining the effect of Spätzle-like protein injection on the expression of genes encoding AT precursor and receptor. All these results are important for understanding the evolutionary basis of hormonal regulation of the immune response.

Artificial light at night drives diel activity patterns of synanthropic pipistrelle bats and their prey

The use of artificial light at night (ALAN) has increased drastically worldwide over the last decades. ALAN can have major effects on nocturnal communities, including insects and bats. Insects are attracted to street lights and few bat species take advantage of this by foraging on the attracted insects. ALAN potentially affects the temporal patterns of insect abundance and thereby bat foraging behaviour. In a natural dark environment, these patterns are usually bimodal, with an activity peak in the early evening and the morning. Little is known about how ALAN affects insect presence throughout the night, and whether the light spectrum plays a role. This is important, as these temporal changes may be a key driver of disturbances in bat-insect interactions. Here, we studied how white and red light affect insects' and bats' nightly activity patterns. The activity of insects and bats (Pipistrellus spp.) was recorded throughout the night at seven experimentally illuminated sites in a forest-edge ecosystem. ALAN disrupted activity patterns, with both insects and bats being more active throughout the night. ALAN facilitated all-night foraging in bats especially near white light, but these effects were attenuated near red light. The ability to forage throughout the night may be a key advantage causing synanthropic bats to dominate in illuminated environments, but this could also prove detrimental in the long term. As red light reduced disturbing effects of ALAN on insects and bats diel activity pattern, it opens the possibility of using spectral composition as a mitigation measure.

A global dataset of diel activity patterns in insect communities

Insect activity powers ecosystems and food production globally. Although insect activity is known to vary with the rise and setting of the sun, there is surprisingly limited empirical information on how insect abundance and richness varies across the 24-hour day–night (diel) cycle. Moreover, commonly used methods for sampling insects such as light traps do not provide suitable comparisons of community properties between diel periods. We present a dataset of 1512 observations of abundance and richness during diurnal and nocturnal periods in insect communities worldwide. The data were collected from 99 studies that systematically sampled insect communities during day and night, using sampling methods minimally influenced by diel variation, such as movement-based interception traps. Spanning six continents, 41 countries and 16 insect orders, the data can support investigations into the factors influencing insect diel preferences as well as the causes and consequences of temporal changes in insect biodiversity. The data also provides key baseline information on the diel activity patterns of insect communities for long-term ecological monitoring. These pursuits take on added significance considering contemporary ‘insect declines’ and increasing anthropogenic impacts on diurnal and nocturnal biodiversity.