Host selection byHylemya antiqua (Meigen)

Abstract

Volatile components ofAllium cepa L, trapped in and recovered from Porapak Q, were separated by gas-liquid and thin-layer chromatography. Fractions eliciting oviposition fromHylemya antiqua (Meigen) were analyzed by combined gas chromatography-mass spectroscopy (GC-MS) and were found to contain saturated and unsaturated disulfides. Authentic samples of the identified components were obtained by synthesis and tested for oviposition response byH.antiqua. Three new attractants and oviposition stimulants forH. antiqua are methyl propyl disulfide,cis-propenyl propyl disulfide, andtrans-propenyl propyl disulfide. All were present in greater proportion in the volatiles from fresh onions than from stored onions. Dimethyl disulfide, methylcis-propenyl disulfide, and methyltrans-propenyl disulfide did not elicit significant oviposition fromH. antiqua.