-
Journal of Economic Entomology Aug 2023Pest insect surveillance using lures is widely used to support market access requirements for traded articles that are hosts or carriers of quarantine pests. Modeling...
Pest insect surveillance using lures is widely used to support market access requirements for traded articles that are hosts or carriers of quarantine pests. Modeling has been used extensively to guide the design of surveillance to support pest free area claims but is less commonly applied to provide confidence in pest freedom or low pest prevalence within sites registered for trade. Site-based surveillance typically needs to detect pests that are already present in the site or that may be entering the site from surrounding areas. We assessed the ability of site-based surveillance strategies to detect pests originating from within or outside the registered site using a probabilistic trapping network simulation model with random-walk insect movement and biologically realistic parameters. For a given release size, time-dependent detection probability was primarily determined by trap density and lure attractiveness, whereas mean step size (daily dispersal) had limited effect. Results were robust to site shape and size. For pests already within the site, detection was most sensitive using regularly spaced traps. Perimeter traps performed best for detecting pests moving into the site, although the importance of trap arrangement decreased with time from release, and random trap placement performed relatively well compared to regularly spaced traps. High detection probabilities were achievable within 7 days using realistic values for lure attractiveness and trap density. These findings, together with the modeling approach, can guide the development of internationally agreed principles for designing site-based surveillance of lure-attractant pests that is calibrated against the risk of non-detection.
Topics: Animals; Insect Control; Moths; Models, Statistical; Pheromones
PubMed: 37312603
DOI: 10.1093/jee/toad112 -
BioRxiv : the Preprint Server For... Apr 2024Females that mate multiply make postmating choices about which sperm fertilize their eggs (cryptic female choice); however, the male characteristics they use to make...
Females that mate multiply make postmating choices about which sperm fertilize their eggs (cryptic female choice); however, the male characteristics they use to make such choices remain unclear. In this study, we sought to understand female sperm use patterns by evaluating whether females adjust sperm use (second male paternity) in response to four main factors: male genotype, male courtship effort, male pheromone alteration, and male postmating reproductive morphology. Our experiment was replicated across four different lines, in a full factorial design, including a pheromone manipulation in which second males were perfumed to resemble heterospecific () males. We found that females prefer longer sperm-regardless of mating order-in almost all contexts; this observed pattern of 'long-sperm precedence' is consistent with female postcopulatory choice of high-fitness male traits. Nonetheless, we also found that this general preference can be plastically altered by females in response to effects including perfuming treatment; this differential female sperm use is between otherwise identical males, and therefore solely female-mediated. Furthermore, our finding that females exercise choice using diverse criteria suggests a possible mechanism for the maintenance of variation in sexually selected male traits.
PubMed: 38712086
DOI: 10.1101/2024.04.25.591180 -
IScience Jul 2023The brown rat () is one of the major animals both in the laboratory and in urban centers. Brown rats communicate various types of information using pheromones, the...
The brown rat () is one of the major animals both in the laboratory and in urban centers. Brown rats communicate various types of information using pheromones, the chemicals that mediate intra-species communication in minute amounts. Therefore, analyses of pheromones would further our understanding of the mode of life of rats. We show that a minute amount of 2-methylbutyric acid (2-MB) released from the neck region can ameliorate fear responses both in laboratory rats and in wild brown rats. Based on these findings, we conclude that 2-MB is an appeasing pheromone in the brown rat. A better understanding of rats themselves would allow us to perform more effective ecologically based research on social skills and pest management campaigns with low animal welfare impacts, which might contribute to furthering the advancement of science and improving public health.
PubMed: 37426349
DOI: 10.1016/j.isci.2023.107081 -
Scientific Reports Apr 2024In this work, we identified the trail pheromone of the ant Crematogaster scutellaris. We combined gas chromatography-mass spectrometry analysis of extracts from the hind...
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 0.001 ng/µL and only at a 1000-fold higher concentration for (S)-tridecan-2-ol, suggesting that only the R enantiomer is used by C. scutellaris in its natural environment. We also found strong behavioural responses to 2-dodecanol, a substance that was not detectable in the hind tibia extract of C. scutellaris, but which has been reported to be the trail pheromone of the related species C. castanea. We discuss the contribution of these results to the 'dissection and reconstruction' of strategies and mechanisms underlying the social organization of ants.
Topics: Animals; Pheromones; Ants; Behavior, Animal; Feeding Behavior
PubMed: 38570567
DOI: 10.1038/s41598-024-58383-2 -
PeerJ. Computer Science 2023The ant colony algorithm (ACA) is a heuristic algorithm that resolves the optimality problem by simulating an ant's foraging process, which finds the shortest path. The...
The ant colony algorithm (ACA) is a heuristic algorithm that resolves the optimality problem by simulating an ant's foraging process, which finds the shortest path. The connotation of the ACA is to find the optimal solution. The Proportional Integral Derivative (PID) parameter tuning is an essential tool in the control field and includes three parameters, Kp, Ki, and Kd, to achieve the best control effect. Besides, tuning the PID parameters is closely related to finding the "optimal" solution that can be attained based on the feasible combination of the two. This article transforms the PID parameter tuning problem into an ACA that finds the optimal solution called ACA-based PID parameters tuning. Furthermore, PID control is simulated by setting the parameters of ACA, such as ant colony size, iteration times, nodes, paths, path evaluation criteria, pheromone concentration, heuristic function, weight factor, and decision function. Eventually, the two PID controller parameter tuning strategies are compared and analyzed, and the advantages and disadvantages of each are obtained. Compared with the 4:1 attenuation curve method, the proposed method can significantly reduce the MP score of the overshoot of the system, increase the time, and improve the dynamic and steady-state performance of the system, but reduce the steady-state error of the system. Therefore, the feasibility and effectiveness of the proposed method is verified.
PubMed: 38077540
DOI: 10.7717/peerj-cs.1660 -
Frontiers in Physiology 2023Odorant-binding proteins (OBPs) are expressed at extremely high concentrations in the chemo-sensilla lymph of insects and have long been thought to be crucial for...
Odorant-binding proteins (OBPs) are expressed at extremely high concentrations in the chemo-sensilla lymph of insects and have long been thought to be crucial for delivering the semiochemicals to the odorant receptors. They are represented by multiple classes: general odorant-binding proteins (GOBP1 and GOBP2) and pheromone-binding proteins. In the current study, we identified a total of 35 OBPs in the antennal transcriptome of , a worldwide pest that causes serious damage to various crops. A gene expression value (TPM, transcripts per million) analysis revealed that seven OBPs (PsauPBP1/2/3, PsauGOBP1/2, PsauOBP6, and PsauOBP8) were highly abundant in the antennae. Next, we focused on the expression and functional characterization of PsauGOBP2. Real-time quantitative-PCR analysis demonstrated that was predominantly expressed in the antennae of both sexes. Fluorescence binding assays showed that the recombinant PsauGOBP2 strongly binds to the female sex pheromone components 11-16: Ac (K = 4.2 μM) and 9-14: Ac (K = 4.9 μM) and binds moderately (6 µM ≤ K ≤ 13 µM) to the host plant volatiles phenylethyl acetate, β-myrcene, and dodecanol. Further 3D structural modeling and molecular docking revealed that several crucial amino acid residues are involved in ligand binding. The results not only increase our understanding of the olfactory system of . but also provide insights into the function of PsauGOBP2 that has implications for developing sustainable approaches for . management.
PubMed: 37637146
DOI: 10.3389/fphys.2023.1241324 -
Insects Feb 2024The tea black tussock moth (), a devastating pest in Chinese tea plantations, uses a ternary Type-II pheromone blend containing (3,6)--9,10-epoxyhenicosa-3,6-diene...
The tea black tussock moth (), a devastating pest in Chinese tea plantations, uses a ternary Type-II pheromone blend containing (3,6)--9,10-epoxyhenicosa-3,6-diene (3,6,epo9-21:H), (3,6,11)--9,10-epoxyhenicosa-3,6,11-triene (3,6,epo9,11-21:H), and (3,6)-henicosa-3,6-dien-11-one (3,6-21:11-one) for mate communication. To elucidate the P450 candidates associated with the biosynthesis of these sex pheromone components, we sequenced the female pheromone gland and the abdomen excluding the pheromone gland. A total of 75 DbP450s were identified. Function annotation suggested six CYPs were orthologous genes that are linked to molting hormone metabolism, and eight antennae specifically and significantly up-regulated CYPs may play roles in odorant processing. Based on a combination of comparative RNAseq, phylogenetic, and tissue expression pattern analysis, one CYP4G with abdomen specifically predominant expression pattern was likely to be the P450 decarbonylase, while the pheromone-gland specifically and most abundant CYP341B65 was the most promising epoxidase candidate for the sex pheromone biosynthesis. Collectively, our research laid a valuable basis not only for further functional elucidation of the candidate P450 decarbonylase and epoxidase for the sex pheromone biosynthesis but also for understanding the physiological functions and functional diversity of the CYP gene superfamily in the .
PubMed: 38392558
DOI: 10.3390/insects15020139 -
Animals : An Open Access Journal From... May 2024Chemical communication is an important mode of communication in the courtship and breeding processes of amphibians. In caudates, multiple components of sexual pheromones...
Chemical communication is an important mode of communication in the courtship and breeding processes of amphibians. In caudates, multiple components of sexual pheromones have been identified and functionally verified. One of these pheromone systems is plethodontid modulating factor (PMF). In anurans, the pheromone called amplexin was found in nuptial pads of ranids and was considered a member of the PMF system, yet its bio-function has not been tested. In this study, we obtained 18 amplexin transcript sequences from nuptial pads of (Amphibia, Ranidae) by transcriptome sequencing and found that the proteins translated by these transcripts are diversified, hydrophilic, and relatively stable. We also acquired a amplexin isoform with the highest expression level in the transcriptome analysis through the prokaryotic expression system. Using two different animal behavioral experimental settings, we have tested the bio-function of the recombinant PMF protein (rPMF) in 's reproduction and found that the rPMF does not attract females but shortens the duration of amplexus significantly. This is the first study to verify the function of the PMF pheromone in Anura, indicating the pervasiveness of chemical communication during breeding in amphibians.
PubMed: 38891597
DOI: 10.3390/ani14111550 -
PLoS Genetics Mar 2024Permanent heterozygous loci, such as sex- or mating-compatibility regions, often display suppression of recombination and signals of genomic degeneration. In...
Permanent heterozygous loci, such as sex- or mating-compatibility regions, often display suppression of recombination and signals of genomic degeneration. In Basidiomycota, two distinct loci confer mating compatibility. These loci encode homeodomain (HD) transcription factors and pheromone receptor (Pra)-ligand allele pairs. To date, an analysis of genome level mating-type (MAT) loci is lacking for obligate biotrophic basidiomycetes in the Pucciniales, an order containing serious agricultural plant pathogens. Here, we focus on four species of Puccinia that infect oat and wheat, including P. coronata f. sp. avenae, P. graminis f. sp. tritici, P. triticina and P. striiformis f. sp. tritici. MAT loci are located on two separate chromosomes supporting previous hypotheses of a tetrapolar mating compatibility system in the Pucciniales. The HD genes are multiallelic in all four species while the PR locus appears biallelic, except for P. graminis f. sp. tritici, which potentially has multiple alleles. HD loci are largely conserved in their macrosynteny, both within and between species, without strong signals of recombination suppression. Regions proximal to the PR locus, however, displayed signs of recombination suppression and genomic degeneration in the three species with a biallelic PR locus. Our observations support a link between recombination suppression, genomic degeneration, and allele diversity of MAT loci that is consistent with recent mathematical modelling and simulations. Finally, we confirm that MAT genes are expressed during the asexual infection cycle, and we propose that this may support regulating nuclear maintenance and pairing during infection and spore formation. Our study provides insights into the evolution of MAT loci of key pathogenic Puccinia species. Understanding mating compatibility can help predict possible combinations of nuclear pairs, generated by sexual reproduction or somatic recombination, and the potential evolution of new virulent isolates of these important plant pathogens.
Topics: Edible Grain; Basidiomycota; Genomics; Genome, Fungal; Reproduction; Plant Diseases
PubMed: 38498573
DOI: 10.1371/journal.pgen.1011207 -
Insects Dec 2023In insects, the chemical senses influence most vital behaviors, including mate seeking and egg laying; these sensory modalities are predominantly governed by odorant...
In insects, the chemical senses influence most vital behaviors, including mate seeking and egg laying; these sensory modalities are predominantly governed by odorant receptors (ORs), ionotropic receptors (IRs), and gustatory receptors (GRs). The codling moth, , is a global pest of apple, pear, and walnut, and semiochemically based management strategies limit the economic impacts of this species. The previous report of expression of a candidate pheromone-responsive OR in female codling moth ovipositor and pheromone glands raises further questions about the chemosensory capacity of these organs. With an RNA-sequencing approach, we examined chemoreceptors' expression in the female codling moth abdomen tip, sampling tissues from mated and unmated females and pupae. We report 37 ORs, 22 GRs, and 18 IRs expressed in our transcriptome showing overlap with receptors expressed in adult antennae as well as non-antennal candidate receptors. A quantitative PCR approach was also taken to assess the effect of mating on OR expression in adult female moths, revealing a few genes to be upregulated or downregulating after mating. These results provide a better understanding of the chemosensory role of codling moth female abdomen tip organs in female-specific behaviors. Future research will determine the function of specific receptors to augment current semiochemical-based strategies for codling moth management.
PubMed: 38132621
DOI: 10.3390/insects14120948