Female Moth Calling and Flight Behavior Are Altered Hours Following Pheromone Autodetection: Possible Implications for Practical Management with Mating Disruption.

Lukasz Stelinski,Cesar Rodriguez-Saona,Robert Holdcraft

doi:10.3390/insects5020459

Lukasz Stelinski, Cesar Rodriguez-Saona + Show 1 more

Open Access

https://doi.org/10.3390/insects5020459

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Abstract

Female moths are known to detect their own sex pheromone—a phenomenon called “autodetection”. Autodetection has various effects on female moth behavior, including altering natural circadian rhythm of calling behavior, inducing flight, and in some cases causing aggregations of conspecifics. A proposed hypothesis for the possible evolutionary benefits of autodetection is its possible role as a spacing mechanism to reduce female-female competition. Here, we explore autodetection in two species of tortricids (Grapholita molesta (Busck) and Choristoneura rosaceana (Harris)). We find that females of both species not only “autodetect,” but that learning (change in behavior following experience) occurs, which affects behavior for at least 24 hours after pheromone pre-exposure. Specifically, female calling in both species is advanced at least 24 hours, but not 5 days, following pheromone pre-exposure. Also, the propensity of female moths to initiate flight and the duration of flights, as quantified by a laboratory flight mill, were advanced in pre-exposed females as compared with controls. Pheromone pre-exposure did not affect the proportion of mated moths when they were confined with males in small enclosures over 24 hours in laboratory assays. We discuss the possible implications of these results with respect to management of these known pest species with the use of pheromone-based mating disruption.

Highlights

Insect sex pheromones are commonly used as a method of pest control with a technique termed “mating disruption” [1]
The earlier onset of calling behavior observed in females that were pre-exposed to pheromone 24 hours earlier was essentially indistinguishable from that observed with females that exhibited an accelerated onset of calling when under a direct stream of pheromone exposure (Figure 1A)
The proportion of females calling at 15:00–17:00 hour was not different between pheromone pre-exposed (24 hours and 5 days prior), directly pheromone-exposed, and control treatments (p > 0.05); and time of calling termination did not differ between treatments (p > 0.05) (Figure 1A)

Summary

Introduction

Insect sex pheromones are commonly used as a method of pest control with a technique termed “mating disruption” [1]. The technique can be highly successful; it is expensive and often requires application to large areas of crop for efficacy [2]. Mating disruption has been investigated and improved upon over several decades with long known examples of success, and with case studies in which the technique’s effectiveness has been highly variable [4]. Mating disruption is known to be density dependent with regard to efficacy and much less effective for certain species that occur under high population densities when pesticides are not co-applied [4,5,6]. In certain cases, mating disruption can be highly effective in a density-independent manner [6,7]

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