Identification of the Female-Produced Sex Pheromone of the Leafminer Holocacista capensis Infesting Grapevine in South Africa.

Hong-Lei Wang,Erik J Van Nieukerken,Christer Löfstedt,Henk Geertsema

doi:10.1007/s10886-015-0611-9

Hong-Lei Wang, Erik J Van Nieukerken + Show 2 more

Open Access

https://doi.org/10.1007/s10886-015-0611-9

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Abstract

We report the first identification of a sex pheromone in a heliozelid moth, Holocacista capensis van Nieukerken & Geertsema. This leafminer recently infested grapevine in South Africa. Compared to solvent extraction of pheromone glands, solid phase microextraction (SPME) proved to be highly effective for collection of the pheromone from calling females. The volatiles collected by SPME were analyzed by gas chromatography with electroantennographic detection (GC/EAD). Three compounds eliciting electrophysiological activity from the male antenna were identified as (Z)-5-tetradecenal, (Z)-7-tetradecenal, and (Z)-9-hexadecenal by coupled gas chromatography–mass spectrometry (GC/MS). GC/MS analysis of dimethyldisulphide (DMDS) derivatives of fatty acyl moieties in pheromone gland extracts confirmed the presence of the corresponding putative pheromone precursors with double bonds in the same position and with Z geometry. Field trapping experiments in a South African vineyard confirmed that both (Z)-5-tetradecenal and (Z)-7-tetradecenal are essential for the attraction of male H. capensis, whereas addition of (Z)-9-hexadecenal to the blend did not affect the attractiveness. The composition of the pheromone is discussed in relation to the phylogeny of this family of moths.

Highlights

Leafmining Lepidoptera, such as the globally problematic citrus leafminer Phyllocnistis citrella Stainton (Gracillariidae) (Heppner and Dixon 1995), and species of the genus Phyllonorycter that attack apple (Maier 2001; Minarro and Jacas 2011) constitute serious economic problems
solid phase microextraction (SPME) proved to be highly effective for the collection of the pheromone from live female adults, even when sampling from a small number of individuals
We identified the sex pheromone of H. capensis as a binary blend of Z5-14:Ald and Z7-14:Ald

Summary

Introduction

Leafmining Lepidoptera, such as the globally problematic citrus leafminer Phyllocnistis citrella Stainton (Gracillariidae) (Heppner and Dixon 1995), and species of the genus Phyllonorycter that attack apple (Maier 2001; Minarro and Jacas 2011) constitute serious economic problems. A heliozelid leafminer has sometimes occurred in high densities in the table grape growing area near Paarl (Western Cape, South Africa), where the presence of this insect is of concern in relation to export of table grapes. This leafminer, considered to be a native South African species, has been described as the new species Holocacista capensis van Nieukerken & Geertsema. The moth, which is only about 1.5 to 2 mm long, occurs in several generations throughout the growing season, including the late summer when the grapes are harvested

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