Attractant for Vinegar Fly, Drosophila busckii, and Cluster Fly, Pollenia rudis (Diptera: Drosophilidae et Calliphoridae)

A field test carried out in an industrial greenhouse in Lithuania revealed the attractiveness of synthetic methyl salicylate (MeSa) to two dipteran species: the vinegar fl y, Drosophila busckii (Drosophilidae), and the cluster fl y, Pollenia rudis (Calliphoridae). The attractant for the former fl y species was especially effective, as sticky traps containing 0.25 ml of MeSa captured (814 ± 55) D. busckii flies/trap on average compared to (12 ± 4) flies/trap in control traps. The mean capture of P. rudis [(42 ± 4) flies/trap] was significantly higher in MeSa-baited traps compared to the control traps [(13 ± 4) flies/trap]. The presence of MeSa in emissions of many fruits suitable for D. busckii feeding allows to attribute this attractant to kairomones. In case of P. rudis, MeSa should be attributed to synomones (compounds beneficial for both receiver and sender), because adult flies feeding on flowers act as pollinators. This is the first report on the field-active attractant for D. busckii and the second for P. rudis.

LOW GENE VARIATION IN DROSOPHILA BUSCKII

ABSTRACT Study of allozyme variation in D. busckii at thirty loci gives the proportion of polymorphic loci =.166 and the proportion of loci heterozygous per individual =.044. D. busckii has a narrower seasonal and food niche than the other domestic species D. melanogaster which has more allozyme variation. It is suggested that the low gene variation in D. busckii might be due to adaptation of this species to a narrow niche.