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Annual Review of Entomology Jan 2024The larval stages of click beetle (Coleoptera: Elateridae) species, several of which are serious agricultural pests, are called wireworms. Their cryptic subterranean... (Review)
Review
The larval stages of click beetle (Coleoptera: Elateridae) species, several of which are serious agricultural pests, are called wireworms. Their cryptic subterranean habitat, resilience, among-species differences in ecology and biology, and broad host range, as well as the lack of objective economic injury thresholds, have rendered wireworms a challenging pest complex to control. Significant progress has been made in recent years, introducing a new effective class of insecticides and improving species identification and our understanding of species-specific phenology, chemical ecology (i.e., adult sex pheromones and larval olfactory cues), and abiotic and biotic factors influencing the efficacy of biological control agents. These new developments have created opportunities for further research into improving our risk assessment, monitoring, and integrated pest management capabilities.
Topics: Animals; Coleoptera; Larva; Insecticides; Ecosystem; Agriculture
PubMed: 37562049
DOI: 10.1146/annurev-ento-120220-123249 -
Journal of Chemical Ecology Apr 2024In most species of moths, the female produces and releases a volatile sex pheromone from a specific gland to attract a mate. Biosynthesis of the most common type of moth...
In most species of moths, the female produces and releases a volatile sex pheromone from a specific gland to attract a mate. Biosynthesis of the most common type of moth sex pheromone component (Type 1) involves de novo synthesis of hexadecanoate (16:Acyl), followed by modification to various fatty acyl intermediates, then reduction to a primary alcohol, which may be acetylated or oxidized to produce an acetate ester or aldehyde, respectively. Our previous work on the moth Chloridea virescens (Noctuidae) showed that females produce 90% of the major pheromone component, (Z)-11-hexadecenal (Z11-16:Ald), via a direct and rapid route of de novo biosynthesis with highly labile intermediates, and ca. 10% from an indirect route that likely mobilizes a pre-synthesized 16-carbon skeleton, possibly, (Z)-11-hexadecenoate (Z11-16:Acyl) or hexadecanoate (16:Acyl). In this paper, we use stable isotope tracer/tracee techniques to study the dynamics of the precursor alcohol (Z)-11-hexadecenol (Z11-16:OH) and stores of Z11-16:Acyl and 16:Acyl to determine their roles in biosynthesis of Z11-16:Ald. We found: (i) that intracellular Z11-16:OH is synthesized at roughly the same rate as Z11-16:Ald, indicating that translocation and oxidation of this moiety does not rate limit biosynthesis of Z11-16:Ald, (ii) intracellular Z11-16:OH consists of two pools, a highly labile one rapidly translocated out of the cell and converted to Z11-16:Ald, and a less labile one that mostly remains in gland cells, (iii) during pheromone biosynthesis, net stores of Z11-16:Acyl increase, suggesting it is not the source of Z11-16:Ald produced by the indirect route, and (iv) no evidence for the gland synthesizing stored 16:Acyl prior to (up to 2 days before eclosion), or after, synthesis of pheromone commenced, suggesting the bulk of this stored moiety is synthesized elsewhere and transported to the gland prior to gland maturation. Thus, the pheromone gland of C. virescens produces very little stored fat over its functional lifetime, being optimized to produce sex pheromone.
Topics: Sex Attractants; Animals; Moths; Female; Aldehydes; Fatty Acids; Alcohols
PubMed: 38374478
DOI: 10.1007/s10886-024-01478-x -
IScience Oct 2023Sex pheromones impart maximal attraction when their components are present at optimal ratios that confer balanced olfactory inputs in potential mates. Altering ratios or...
Sex pheromones impart maximal attraction when their components are present at optimal ratios that confer balanced olfactory inputs in potential mates. Altering ratios or adding pheromone analogs to optimal mixtures may disrupt balanced olfactory antagonism and result in reduced attraction, however, tests in natural populations are lacking. We tested this hypothesis in sea lamprey (), a fish whose male sex pheromone attracts females when two critical components, 3-keto petromyzonol sulfate (3kPZS) and petromyzonol sulfate (PZS), are present at certain ratios. Here, we report a pheromone analog, petromyzonol tetrasulfate (3sPZS), reduced female attraction to 3kPZS but not to PZS. 3sPZS mixed with additional PZS synergistically disrupted female attraction to the male pheromone and reduced spawning by 97% in a high-density population. Our results provide evidence of balanced olfactory antagonism in a vertebrate and establish a tactic to disrupt spawning of sea lamprey, a destructive invader of the Laurentian Great Lakes.
PubMed: 37810212
DOI: 10.1016/j.isci.2023.107744 -
Insects Jun 2024Chestnuts ( Siebold and Zucc.) are one of the major agroforestry products in Korea, and is a major pest of the chestnut fruit. Pheromone-based mating disruption (MD)...
Chestnuts ( Siebold and Zucc.) are one of the major agroforestry products in Korea, and is a major pest of the chestnut fruit. Pheromone-based mating disruption (MD) has emerged as a promising eco-friendly approach to reduce population levels and ultimately mitigate fruit damage. Field trials were conducted over two years (2022-2023) in two commercial chestnut orchards in Central Korea that were infested with . Compared with the control treatment, the MD treatment effectively reduced the number of male captured in the MD treatment plots. Male catch inhibition (MCI) rates ranged from 70.5% to 82.7% in 2022 and from 87.8% to 95.1% in 2023. The MD efficacy (%) was calculated based on the total number of chestnut fruits collected and the number of fruits damaged by . In 2022, the MD efficacy of the single-dosage treatment (TS, 50 g/ha) was 63.9% in Orchard A and 73.6% in Orchard B. In 2023, the MD efficacies of the double-dosage treatment (TD, 100 g/ha) and the two-application treatment (TT, 50 g/ha in June and August) were 60.2% and 77.9% in Orchard A and 50.9% and 64.8% in Orchard B, respectively. This study confirms the efficacy of pheromone-based MD in reducing the numbers in chestnut orchards and damage to chestnut fruits.
PubMed: 38921160
DOI: 10.3390/insects15060445 -
Animals : An Open Access Journal From... Sep 2023Problem behaviours in cats, such as urine marking, scratching, fear, and problems of cohabitation between cats, can present a potential welfare problem for those...
Problem behaviours in cats, such as urine marking, scratching, fear, and problems of cohabitation between cats, can present a potential welfare problem for those affected cats and have a negative impact on the human-animal bond. The aim of this study was to develop a Cat Behaviour Issues Assessment Scale (CABIAS) for caregivers to assess these common problem behaviours in cats, and to investigate aspects of the validity and reliability of the CABIAS. The CABIAS uses an index score as a scoring system combining aspects of the frequency and intensity of the problem behaviour. An electronic survey was developed, and 384 households, each with two participants able to observe the cat's behaviour, were recruited for the study. The participants were asked to record their cat's behaviour independently at weekly intervals over a 6-week period. A FELIWAY Optimum diffuser (containing a commercial feline pheromone complex) was provided to half of the participants, to be used during part of the study. The participants were subdivided into four groups according to whether a problem behaviour was present (or not) and whether the pheromone diffuser was provided (or not). The results demonstrated that the index scores for each problem behaviour had very high inter-rater reliability. There was a high correlation between the index scores and the impact the problem behaviours had on the caregivers. In those cats with a declared problem behaviour where the product was used, a reduction in index scores was observed over the duration of the study. The CABIAS was shown to exhibit satisfactory validity, reliability, and sensitivity to change in the current study, suggesting that it may be valuable as a tool for assessing and monitoring scratching, inter-cat cohabitation, urine marking, and fear in cats. The CABIAS could be used by veterinarians and behaviourists to assess these problem behaviours in individual cats and monitor responses to treatment. The CABIAS could also be considered as a research tool to assess the efficacy of interventions aimed at improving these problems.
PubMed: 37760392
DOI: 10.3390/ani13182992 -
Scientific Reports Feb 2024In the Americas, the fall armyworm (Spodoptera frugiperda) exists in two genetically distinct strains, the corn (C) and rice (R) strains. Despite their names, these...
In the Americas, the fall armyworm (Spodoptera frugiperda) exists in two genetically distinct strains, the corn (C) and rice (R) strains. Despite their names, these strains are not associated with host plant preferences but have been shown to vary in pheromone composition and male responses. Recently, S. frugiperda was detected in Africa as an invasive species, but knowledge about variation in strain types, pheromone composition and inter-strain mating of populations of the pest in the continent has not been fully examined. Therefore, this study aimed to investigate variations, if any in the pheromone composition of female moths, male moth responses, and mating between C and R mitotypes of S. frugiperda populations in Kenya, as well as their geographic distribution. Strains (mitotypes) of S. frugiperda were identified using mitochondrial DNA (mtDNA) markers, and their pheromonal composition determined by coupled gas chromatography-mass spectrometric (GC-MS) analysis. Male moth responses to these compounds were evaluated using GC-electroantennographic detection (EAD), electroantennogram (EAG), and wind tunnel assays. Oviposition assays were used to determine whether R and C mitotype moths could mate and produce eggs. The results showed that both the R and C mitotypes were present, and there were no statistically significant differences in their distribution across all sampled locations. Five pheromone compounds including (Z)-7-dodecenyl acetate (Z7-12:OAc), (Z)-7-tetradecenyl acetate (Z7-14:OAc), (Z)-9-tetradecenyl acetate (Z9-14:OAc), (Z)-11-tetradecenyl acetate (Z11-14:OAc) and (Z)-11-hexadecenyl acetate (Z11-16:OAc), were detected in the pheromone glands of female moths of both mitotypes, with Z9-14:OAc being the most abundant. The relative percentage composition of Z9-14:OAc was similar in both mitotypes. However, the R mitotype had a 2.7 times higher relative percentage composition of Z7-12:OAc compared to the C mitotype moth, while the C mitotype moth had a 2.4 times higher relative percentage composition of Z11-16:OAc than the R mitotype moth. Male moths of both mitotypes exhibited similar responses to the pheromone compounds, showing the strongest responses to Z9-14:OAc and Z7-12:OAc in electrophysiological and behavioural assays. There was mating between R and C mitotypes with egg production comparable to mating within the same mitotype. Our results revealed that differences between the two S. frugiperda mitotypes are characterized by female moth pheromone composition rather than male moth responses to the pheromones, and that this does not prevent hybridisation between the mitotypes, which may have implications for their management.
Topics: Animals; Female; Spodoptera; Sex Attractants; Pheromones; Moths; Kenya
PubMed: 38360933
DOI: 10.1038/s41598-024-53053-9 -
Plant Biotechnology Journal Jul 2023Previous work has demonstrated that plants can be used as production platforms for molecules used in health, medicine, and agriculture. Production has been exemplified...
Previous work has demonstrated that plants can be used as production platforms for molecules used in health, medicine, and agriculture. Production has been exemplified in both stable transgenic plants and using transient expression strategies. In particular, species of Nicotiana have been engineered to produce a range of useful molecules, including insect sex pheromones, which are valued for species-specific control of agricultural pests. To date, most studies have relied on strong constitutive expression of all pathway genes. However, work in microbes has demonstrated that yields can be improved by controlling and balancing gene expression. Synthetic regulatory elements that provide control over the timing and levels of gene expression are therefore useful for maximizing yields from heterologous biosynthetic pathways. In this study, we demonstrate the use of pathway engineering and synthetic genetic elements for controlling the timing and levels of production of Lepidopteran sex pheromones in Nicotiana benthamiana. We demonstrate that copper can be used as a low-cost molecule for tightly regulated inducible expression. Further, we show how construct architecture influences relative gene expression and, consequently, product yields in multigene constructs. We compare a number of synthetic orthogonal regulatory elements and demonstrate maximal yields from constructs in which expression is mediated by dCas9-based synthetic transcriptional activators. The approaches demonstrated here provide new insights into the heterologous reconstruction of metabolic pathways in plants.
Topics: Animals; Nicotiana; Sex Attractants; Plants, Genetically Modified; Insecta
PubMed: 37032497
DOI: 10.1111/pbi.14048 -
Scientific Reports Nov 2023Sexual signals often function in species recognition and may also guide mate choice within a species. In noctuid moths, both males and females may exercise mate choice....
Sexual signals often function in species recognition and may also guide mate choice within a species. In noctuid moths, both males and females may exercise mate choice. Females of the tobacco budworm Chloridea virescens prefer to mate with larger males, but the signal(s) underlying female choice remain unknown. Male hairpencil volatiles are emitted during close range courtship displays. However, previously identified male hairpencil volatiles, namely acetate esters, aldehydes, alcohols, and fatty acids, are not associated with female choice. Recently, two new hairpencil compounds were identified that elicit strong electrophysiological responses in female antennae: methyl salicylate (MeSA) and δ-decalactone. In this study, we investigated the effect of larval diet and adult feeding on MeSA and δ-decalactone content in hairpencils and determined whether these compounds are involved in female choice. We found that larval diet affected MeSA content in hairpencils, but not δ-decalactone. Conversely, adult feeding affected the level of δ-decalactone, but not MeSA: sugar-water feeding increased δ-decalactone content compared to plain water. In two-choice assays, females mated more with males that had higher amounts of δ-decalactone, and less with males with higher amounts of MeSA.
Topics: Female; Male; Animals; Sex Attractants; Pheromones; Sexual Behavior, Animal; Moths; Larva; Diet; Water
PubMed: 37957216
DOI: 10.1038/s41598-023-47041-8 -
Design of Polymer Carriers for Optimized Pheromone Release in Sustainable Insect Control Strategies.Advanced Science (Weinheim,... Mar 2024Semiochemicals such as pheromones play a major role in communication between insects, influencing their spatial orientation, aggregation, defense, and mating. The... (Review)
Review
Semiochemicals such as pheromones play a major role in communication between insects, influencing their spatial orientation, aggregation, defense, and mating. The rational chemical design of precision pheromone-releasing materials are increased the efficiency of pheromone-based plant protection agents. Decades of research is begun to unravel the complex communication structures regulated by semiochemicals, from the neuronal perception of specific chemical substances to the behavioral responses in hundreds of species, including many devastating pest insects. This article summarizes the most effective uses of semiochemicals in agriculture, the behavioral responses of selected target species, and controlled-release strategies based on formulations such as novel fibrous polymer carriers. This study helps scientists, decision-makers, farmers, and the public understand the importance of appropriate mating disruption techniques that reduce the need for broad-spectrum insecticides and limit their impact on non-target and beneficial insects.
Topics: Animals; Pheromones; Insect Control; Insecta
PubMed: 38145363
DOI: 10.1002/advs.202304098 -
ELife Dec 2023In and other insects, the seminal fluid proteins (SFPs) and male sex pheromones that enter the female with sperm during mating are essential for fertility and induce...
In and other insects, the seminal fluid proteins (SFPs) and male sex pheromones that enter the female with sperm during mating are essential for fertility and induce profound post-mating effects on female physiology. The SFPs in and other taxa include several members of the large gene family known as odorant binding proteins (Obps). Work in has shown that some genes are highly expressed in the antennae and can mediate behavioral responses to odorants, potentially by binding and carrying these molecules to odorant receptors. These observations have led to the hypothesis that the seminal Obps might act as molecular carriers for pheromones or other compounds important for male fertility, though functional evidence in any species is lacking. Here, we used functional genetics to test the role of the seven seminal Obps in fertility and the post-mating response (PMR). We found that is required for male fertility and the induction of the PMR, whereas the other six genes are dispensable. We found males lacking fail to form a mating plug in the mated female's reproductive tract, leading to ejaculate loss and reduced sperm storage, likely due to its expression in the male ejaculatory bulb. We also examined the evolutionary history of these seminal genes, as several studies have documented rapid evolution and turnover of SFP genes across taxa. We found extensive lability in gene copy number and evidence of positive selection acting on two genes, and . Comparative RNAseq data from the male reproductive tract of multiple species revealed that shows high male reproductive tract expression in a subset of taxa, though conserved head expression across the phylogeny. Together, these functional and expression data suggest that may have been co-opted for a reproductive function over evolutionary time.
Topics: Male; Female; Animals; Drosophila melanogaster; Odorants; Drosophila Proteins; Seeds; Fertility; Spermatozoa; Sexual Behavior, Animal
PubMed: 38126735
DOI: 10.7554/eLife.86409