Pheromone

Insects heavily rely on the olfactory system for food, mating, and predator evasion. However, the caste-related olfactory differences in Apis cerana , a eusocial insect, remain unclear. To explore the peripheral and primary center of the olfactory system link to the caste dimorphism in A. cerana , transcriptome and immunohistochemistry studies on the odorant receptors (ORs) and architecture of antennal lobes (ALs) were performed on different castes. Through transcriptomesis, we found more olfactory receptor genes in queens and workers than in drones, which were further validated by RT-qPCR, indicating caste dimorphism...

Many gregarious insect species use aggregation and alarm pheromones. The bed bug, Cimex lectularius L., emits an alarm pheromone (AP), a 70/30 blend of (E)-2-hexenal and (E)-2-octenal, when threatened. Bed bugs avoid temperatures above 43 °C, which are lethal to bugs and used commercially as spatial heat treatments to manage infestations. However, the interaction of bed bug AP in heat avoidance has not been investigated. The goal of this research was to: 1) determine if bed bugs emit AP as an alarm response to heat exposure, and 2) quantify the behavioral responses of conspecifics to AP emitted by heat-exposed bed bugs...

Animals employ different strategies to establish mating boundaries between closely related species, with sex pheromones often playing a crucial role in identifying conspecific mates. Many of these pheromones have carbon-carbon double bonds, making them vulnerable to oxidation by certain atmospheric oxidant pollutants, including ozone. Here, we investigate whether increased ozone compromises species boundaries in drosophilid flies. We show that short-term exposure to increased levels of ozone degrades pheromones of Drosophila melanogaster, D...

Spraying urine on vertical objects by raising the tail is a commonly observed functional behavior for chemical communication in Felidae species, including domestic cats (Felis silvestris catus). The sprayed urine is recognized as a chemical signal for territorial ownership of their habitats. Previous studies reported that sprayed urine emits a more pungent odor than urine excreted from a squatting position. However, little is known about how sprayed urine acts as a strong scent mark in the environment. Here, we showed that sprayed urine originates only from bladder urine without any secretions, such as anal sac secretions, but it can effectively emit volatile organic compounds (VOCs) when smeared on vertical objects due to its strong adhesion...

Ant behavior relies on a collection of natural products, from following trail pheromones during foraging to warding off potential predators. How nervous systems sense these compounds to initiate a behavioral response remains unclear. Here, we used Caenorhabditis elegans chemotaxis assays to investigate how ant compounds are detected by heterospecific nervous systems. We found that C. elegans avoid extracts of the pavement ant ( Tetramorium immigrans ) and either osm-9 or tax-4 ion channels are required for this response...

BACKGROUND: The odours of different body parts and structures, such as external genitalia, female urine, ventral tail radix, infraorbital sinus and interdigital sinus, have a strong attractiveness for rams. The sinus interdigitalis is considered an important trail gland for sexual behaviour, as its odour is included in the list of strongly attractive structures for male animals during the breeding season, being important in pheromone production. OBJECTIVES: In the present study, the effects of sex and breeding season on the morphological and histological structure of the interdigital gland were investigated in Hamdani crossbred sheep (Ovis aries)...

Studies of adaptive radiations have played a central role in our understanding of reproductive isolation. Yet the focus has been on human-biased visual and auditory signals, leaving gaps in our knowledge of other modalities. To date, studies on chemical signals in adaptive radiations have focused on systems with multimodal signalling, making it difficult to isolate the role chemicals play in reproductive isolation. In this study we examine the use of chemical signals in the species recognition and adaptive radiation of Hawaiian Tetragnatha spiders by focusing on entire communities of co-occurring species, and conducting behavioural assays in conjunction with chemical analysis of their silks using gas chromatography-mass spectrometry...

Decisions made over long time scales, such as life cycle decisions, require coordinated interplay between sensory perception and sustained gene expression. The Caenorhabditis elegans dauer (or diapause) exit developmental decision requires sensory integration of population density and food availability to induce an all-or-nothing organismal-wide response, but the mechanism by which this occurs remains unknown. Here, we demonstrate how the ASJ chemosensory neurons, known to be critical for dauer exit, perform sensory integration at both the levels of gene expression and calcium activity...

Moth insects rely on sex pheromones for long distance attraction and searching for sex partners. The biosynthesis of moth sex pheromones involves the catalytic action of multiple enzymes, with desaturases playing a crucial role in the process of carbon chain desaturation. However, the specific desaturases involved in sex pheromone biosynthesis in fall armyworm (FAW), Spodoptera frugiperda, have not been clarified. In this study, a Δ11 desaturase (SfruDES1) gene in FAW was knocked out using the CRISPR/Cas9 genome editing system...

In this work, we identified the trail pheromone of the ant Crematogaster scutellaris. We combined gas chromatography-mass spectrometry analysis of extracts from the hind tibia, the location of the respective glands, with automated trail following assays. The study found tridecan-2-ol to be the strongest discriminator between hind tibia and other body part extracts. Tridecan-2-ol elicited trail-following behaviour at concentrations of 1 ng/µL. A separation of the enantiomers showed responses to (R)-tridecan-2-ol already at 0...

Fast and effective monitoring and surveillance techniques are crucial for the swift implementation of control methods to prevent the spread of Huanglongbing, a devastating citrus disease, and its invasive psyllid vector, Asian citrus psyllid, Diaphorina citri, into South Africa, as well as to control the native vector, African citrus triozid, Trioza erytreae. Monitoring for citrus psyllid pests can be improved by using semiochemical odorants to augment already visually attractive yellow sticky traps. However, environmental variables such as temperature and humidity could influence odorant release rates...

BACKGROUND: Halyomorpha halys is one of the most damaging invasive agricultural pests in north America and southern Europe. It is commonly monitored using pheromone traps, which are not very effective as few bugs are caught, some escape and/or remain outside the trap on surrounding plants where they feed, increasing the damage. Other monitoring techniques are based on visual sampling, sweep netting and tree-beating. However, all these methods require several hours of human labour and are difficult to apply to large areas...

BACKGROUND: Lactobacillus acidophilus is lactic acid bacteria that produce bacteriocins. Bacteriocins are antimicrobial peptides or proteins that exhibit activity against closely related bacteria. The aim of this study was to determine the effect of L. acidophilus ATCC 4356 bacteriocin against Staphylococcus aureus. Material and Methods . We used four different phenotypic methods for antimicrobial activities against two standard strains: methicillin-resistant S. aureus (MRSA) ATCC 33591 and methicillin-susceptible S...

Male cerambycid beetles of the large subfamilies Cerambycinae and Lamiinae produce aggregation-sex pheromones that attract both sexes. The pheromones of many species are conserved among both closely related species (e.g., congeners) and more distantly related species (e.g., different subfamilies), including those endemic to different continents. This parsimony in pheromone structures suggests that multiple species may be attracted to traps baited with blends of pheromones, and such blends are finding use in delineating geographic ranges of native species and in surveillance programs for incursions of exotic species...

The southern pine beetle, Dendroctonus frontalis Zimmermann is an important mortality agent of Pinus in the eastern United States of America where it commonly shares hosts with the black turpentine beetle, Dendroctonus terebrans (Olivier), which infrequently kills trees. Unlike D. frontalis, which must kill its hosts to become established in the bark and reproduce, D. terebrans can occupy living hosts as a parasite. Olfactory mechanisms whereby D. frontalis initially locates hosts have not been demonstrated, whereas D...

Extracellular vesicles (EVs) are integral to numerous biological processes, yet it is unclear how environmental factors or interactions among individuals within a population affect EV-regulated systems. In Caenorhabditis elegans, the evolutionarily conserved large EVs, known as exophers, are part of a maternal somatic tissue resource management system. Consequently, the offspring of individuals exhibiting active exopher biogenesis (exophergenesis) develop faster. Our research focuses on unraveling the complex inter-tissue and social dynamics that govern exophergenesis...

The impact of organometallic chemistry on the terpene field only really blossomed in the 1960s and 1970s with the realisation that carbon-carbon bond formation under mild conditions could be achieved by using nickel or iron carbonyls as synthetic reagents. Concomitantly, the development of palladium derivatives capable of the controlled coupling of isoprene units attracted the attention of numerous highly talented researchers, including future Nobel laureates. We discuss briefly how early work on the syntheses of simple monoterpenes soon progressed to sesquiterpenes and diterpenes of increasing complexity, such as humulene, flexibilene, vitamin A, or pheromones of commercial value, in particular those used in perfumery (muscone, lavandulol), or grandisol and red scale pheromone as replacements for harmful pesticides...

The effects of climate change are becoming more apparent, predominantly concerning the impacts of ocean acidification on calcifying species. Many marine organisms rely on chemical signals for processes such as foraging for food, predator avoidance, or locating mates. The process of how chemical cues in marine invertebrates function, and how this sensory mode is affected by pH levels, is less researched. We tested the impact of reduced pH (7.6), simulating end-of-the-century predicted average ocean pH, against current oceanic pH conditions (8...

Quantitative real-time PCR (qRT-PCR) is a widely applied technique for accurately assessing the expression of target genes. In practice, the evaluation of gene expression requires appropriate reference genes. To screen reliable reference genes for evaluating gene expression via qRT-PCR in Mythimna loreyi , a notorious migratory pest across Asia, Africa, Europe, and Australia, we assessed the expression stability of 13 candidate reference genes in M. loreyi using the ΔCt method, BestKeeper, Normfinder, GeNorm, and the web-based comprehensive platform RefFinder...

"Calling behaviour" is a stereotyped rhythmic motor pattern displayed by female moths, by which they emit the sex pheromone to attract of conspecific males. Calling occurs through a squeezing mechanism based on the turtleneck-like folding and unfolding of the ovipositor cuticle during its telescopic extensions and retractions. This mechanism is under the control of the terminal abdominal ganglion (TAG). By combining anatomical and electrophysiological approaches, here we studied the morpho-functional organisation of the abdominal muscles and the activity of motoneurons from TAG nerve N4-N6 as correlated to the ovipositor movements during calling in the female spongy moth Lymantria dispar ...