skip to main content

Attention:

The NSF Public Access Repository (NSF-PAR) system and access will be unavailable from 11:00PM ET on Friday, December 15 until 2:00 AM ET on Saturday, December 16 due to maintenance. We apologize for the inconvenience.


Title: Geographic variation in sexual communication in the cotton bollworm, Helicoverpa armigera
Abstract BACKGROUND

Geographic variation in male response to sex pheromone lures has been studied in the field in a number of moth species. However, only a few studies have investigated geographic variation in female calling and sex pheromone under field conditions. For an effective field implementation of sex pheromone lures, it is essential to know the local sex pheromone blend and local timing of sexual communication. We investigated the level and extent of geographic variation in the sexual communication of the important agricultural pestHelicoverpa armigera(Lepidoptera, Noctuidae) in three continents.

RESULTS

We found there is no genetic variation in the calling behavior ofH. armigera. In the female sex pheromone, we found more between‐population variation than within‐population variation. In male response experiments, we found geographic variation as well. Strikingly, when adding the antagonistic compound Z11‐16:OAc to the pheromone blend ofH. armigera, significantly fewer males were caught in Australia and China, but not in Spain. This variation is likely not only due to local environmental conditions, such as photoperiod and temperature, but also to the presence of other closely related species with which communication interference may occur.

Conclusion

Finding geographic variation in both the female sexual signal and the male response in this pest calls for region‐specific pheromone lures. Our study shows that the analysis of geographic variation in moth female sex pheromones as well as male responses is important for effectively monitoring pest species that occur around the globe. © 2020 The Authors.Pest Management Sciencepublished by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

 
more » « less
NSF-PAR ID:
10456864
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Pest Management Science
Volume:
76
Issue:
11
ISSN:
1526-498X
Page Range / eLocation ID:
p. 3596-3605
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Abstract

    Patterns of mating for the European corn borer (Ostrinia nubilalis) moth depend in part on variation in sex‐pheromone blend. The ratio of (E)‐11‐ and (Z)‐11‐tetradecenyl acetate (E11‐ and Z11‐14:OAc) in the pheromone blend that females produce and males respond to differs between strains ofO. nubilalis. Populations also vary in female oviposition preference for and larval performance on maize (C4) and nonmaize (C3) host plants. The relative contributions of sexual and ecological trait variation to the genetic structure ofO. nubilalisremains unknown. Host‐plant use (13C/14C ratios) and genetic differentiation were estimated among sympatric E and Z pheromone strainO. nubilalismales collected in sex‐pheromone baited traps at 12 locations in Pennsylvania and New York between 2007 and 2010. Among genotypes at 65 single nucleotide polymorphism marker loci, variance at a position in the pheromone gland fatty acyl‐reductase (pgfar) gene at the locus responsible for determining female pheromone ratio (Pher) explained 64% of the total genetic differentiation between males attracted to different pheromones (male response,Resp), providing evidence of sexual inter‐selection at these unlinked loci. Principal coordinate, Bayesian clustering, and distance‐based redundancy analysis (dbRDA) demonstrate that host plant history or geography does not significantly contribute to population variation or differentiation among males. In contrast, these analyses indicate that pheromone response andpgfar‐defined strain contribute significantly to population genetic differentiation. This study suggests that behavioural divergence probably plays a larger role in driving genetic variation compared to host plant‐defined ecological adaptation.

     
    more » « less
  2. Abstract

    The sex pheromone system of ~160,000 moth species acts as a powerful form of assortative mating whereby females attract conspecific males with a species-specific blend of volatile compounds. Understanding how female pheromone production and male preference coevolve to produce this diversity requires knowledge of the genes underlying change in both traits. In the European corn borer moth, pheromone blend variation is controlled by two alleles of an autosomal fatty-acyl reductase gene expressed in the female pheromone gland (pgFAR). Here we show that asymmetric male preference is controlled bycis-acting variation in a sex-linked transcription factor expressed in the developing male antenna,bric à brac(bab). A genome-wide association study of preference using pheromone-trapped males implicates variation in the 293 kbbabintron 1, rather than the coding sequence. Linkage disequilibrium betweenbabintron 1 andpgFARfurther validatesbabas the preference locus, and demonstrates that the two genes interact to contribute to assortative mating. Thus, lack of physical linkage is not a constraint for coevolutionary divergence of female pheromone production and male behavioral response genes, in contrast to what is often predicted by evolutionary theory.

     
    more » « less
  3. Abstract Background

    The fall armyworm (FAW),Spodoptera frugiperda(J.E. Smith), is a global pest that feeds on >350 plant species and severely limits production of cultivated grasses, vegetable crops and cotton. An efficient way to detect new invasions at early stages, and monitor and quantify the status of established infestations of this pest is to deploy traps baited with species‐specific synthetic sex pheromone lures.

    Results

    We re‐examined the compounds in the sex pheromone glands of FAW females by gas chromatography‐electroantennogram detector (GC‐EAD), GC–mass spectrometry (MS), behavioral and field assays. A new bioactive compound from pheromone gland extracts was detected in low amounts (3.0% relative to (Z)‐9‐tetradecenyl acetate (Z9‐14:OAc), the main pheromone component), and identified as nonanal. This aldehyde significantly increased attraction of male moths to a mix of Z9‐14:OAc and (Z)‐7‐dodecenyl acetate in olfactometer assays. Adding nonanal to this two‐component mix also doubled male trap catches relative to the two‐component mix alone in cotton fields, whereas nonanal alone did not attract any moths. The addition of nonanal to each of three commercial pheromone lures also increased male catches by 53–135% in sorghum and cotton fields.

    Conclusion

    The addition of nonanal to pheromone lures should improve surveillance, monitoring and control of FAW populations. © 2023 The Authors.Pest Management Sciencepublished by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

     
    more » « less
  4. Abstract

    Binary communication systems that involve sex‐specific signaling and sex‐specific signal perception play a key role in sexual selection and in the evolution of sexually dimorphic traits. The driving forces and genetic changes underlying such traits can be investigated in systems where sex‐specific signaling and perception have emerged recently and show evidence of potential coevolution. A promising model is found inDrosophila prolongata, which exhibits a species‐specific increase in the number of male chemosensory bristles. We show that this transition coincides with recent evolutionary changes in cuticular hydrocarbon (CHC) profiles. Long‐chain CHCs that are sexually monomorphic in the closest relatives ofD. prolongata(D. rhopaloa,D. carrolli,D. kurseongensis, andD. fuyamai) are strongly male‐biased in this species. We also identify an intraspecific female‐limited polymorphism, where some females have male‐like CHC profiles. Both the origin of sexually dimorphic CHC profiles and the female‐limited polymorphism inD. prolongatainvolve changes in the relative amounts of three mono‐alkene homologs, 9‐tricosene, 9‐pentacosene, and 9‐heptacosene, all of which share a common biosynthetic origin and point to a potentially simple genetic change underlying these traits. Our results suggest that pheromone synthesis may have coevolved with chemosensory perception and open the way for reconstructing the origin of sexual dimorphism in this communication system.

     
    more » « less
  5. SUMMARY  
    more » « less