Comparative behavioral and EAG responses of female obliquebanded and redbanded leafroller moths (Lepidoptera: Tortricidae) to their sex pheromone components

Abstract

Abstract. Studies were conducted investigating the responses of female obliquebanded leafrollers, Choristoneura rosaceana (Harris) and redbanded leafrollers, Argyrotaenia velutinana (Walker) (Lepidoptera: Tortricidae), to components of their sex pheromone. Electroantennogram (EAG) recordings revealed significant responses from antennae of female moths of both species to the major pheromone component, (Z)-11-tetradecenyl acetate, at dosages ranging from 2 µg -2 mg. However, tested individually, the minor pheromone components of the obliquebanded leafroller, (E)-11-tetradecenyl acetate and (Z)-11-tetradecenol, elicited little or no antennal response from conspecific females. This result was consistent for redbanded leafroller females, which showed only weak responses to the minor component (E)-11-tetradecenyl acetate at a 2 mg dosage. For both species, species-specific blend ratios of the Z and E isomers of tetradecenyl acetate did not elicit a greater antennal response than the Z isomer alone. Virgin females of each species (2-4 d old) were placed into 1-liter plastic assay chambers with constant throughput of carbon-filtered air passed through 1-liter flasks containing rubber septa loaded with (Z)-and (E)-11-tetradecenyl acetates and (Z)-11-tetradecenol for trials with female obliquebanded leafrollers or with (Z)-and (E)-11-tetradecenyl acetates and dodecyl acetate for trials with female redbanded leafrollers. Exposure to pheromone-permeated air delayed the onset of calling by 1 h and terminated the calling period 1 h earlier for both species compared with solvent-control exposed females. Furthermore, the total proportion of calling females was reduced by half in chambers receiving constant throughput of pheromone-permeated air compared with solvent controls. Exposure to pheromonepermeated air also significantly reduced egg-laying in both species compared with clean-air controls. Furthermore, application of the major pheromone component, (Z)-11-tetradecenyl acetate, at dosages ranging from 2 µg-2 mg to wax-paper ovipositional substrates, deterred oviposition by females of both species. Our data suggest that application of synthetic sex-attractant pheromones for mating disruption of leafroller species may have deleterious effects on female moth behavior, which may contribute to pest control. Field investigations will need to be conducted to test this hypothesis. 187* Corresponding author; current address:

Sex pheromone recognition and characterization of three pheromone-binding proteins in the legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae)

“…Moreover, based on the higher expression of MvitPBP1 gene in male M. vitrata than that of the other PBP genes, MvitPBP1 gene might have a major role in male-female recognition. Furthermore, female-biased expression of both of MvitPBP2 and MvitPBP3 genes might indicate involvement in the autodetection of sex pheromone compounds, which has been demonstrated in other lepidopterans 47 48 49 50 .…”

Asian corn borer pheromone binding protein 3, a candidate for evolving specificity to the 12-tetradecenyl acetate sex pheromone

“…Alternatively, PBPs expressed in female antenna may play a role in the autodetection of pheromone compounds. Autodetection has been demonstrated by electroantennography in some Lepidoptera species (Gokce et al, 2007;Groot et al, 2005;Stelinski et al, 2006;Yang et al, 2009). Fig.…”

Autodetection in <i>Helicoverpa armigera</i> (Hubner)

“…However, the response of unmated males to pheromone blends has been well documented in earlier studies 24 . Autodetection was earlier reported from other moths such as Panaxia quadripunctaria 14 , Choristoneura rosaceana 25 and Grapholitha molesta (Busck) 26 . The role of sensilla trichodea in the perception of sex pheromones of females in H. armigera and other moths was reported by earlier workers 27,28 .…”

“…Exposure to pheromone-permeated ovipostional sites reduced egg laying in females of C. rosaceana and Aryrotaenia velutinana 25 . However, in the present study no change was observed in the oviposition behaviour of H. armigera.…”