The spotted-wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), native to Eastern Asia, is an invasive alien species in Europe and the Americas, where it is a severe pest of horticultural crops, including soft fruits and wine grapes. The conventional approach to controlling infestations of SWD involves the use of insecticides, but the frequency of application for population management is undesirable. Consequently, alternative strategies are urgently needed. Effective and improved trapping is important as an early risk detection tool. This study aimed to improve Droskidrink® (DD), a commercially available attractant for SWD. We focused on the chemical and behavioral effects of adding the bacterium Oenococcus oeni (Garvie) to DD and used a new trap design to enhance the effects of attractive lures. We demonstrate that microbial volatile compounds produced by O. oeni are responsible for the increase in the attractiveness of the bait and could be later utilized for the development of a better trapping system. Our results showed that the attractiveness of DD was increased up to two-fold by the addition of commercially available O. oeni when combined with an innovative trap design. The new trap-bait combination increased the number of male and especially female catches at low population densities.

(1) Monitoring of Drosophila suzukii is based on the use of effective traps and baits. The current baits are insufficient to provide efficient monitoring. The use of bacteria as bio-catalyzers to produce bioactive volatiles may improve flies’ attraction. Thus, we conducted this work to improve Droskidrink® bait’s attractiveness using lactic acid bacteria. (2) Different baits that were based on the use of Droskidrink® were assessed for flies’ attraction in a Droso-Trap® in a vineyard. Oenococcus oeni, Pediococcus spp., and Lactobacillus spp. were used. The performance of the most attractive species, O. oeni, inoculated into Droskidrink® was assessed in laboratory tests. The responses of female flies to volatiles produced by Droskidrink® with O. oeni strains were recorded by electroantennography. (3) Preliminary field assessment of baits recorded O. oeni as the most attractive species. Three strain groups showed adaptation to test conditions. Volatiles extracted by the headspace of baits inoculated with O. oeni, elicited electroantennographic responses from fly antennae. (4) Droskidrink® inoculated with O. oeni is a highly attractive bait for monitoring. These findings will be useful for improving the attractiveness of D. suzukii commercial baits based on the utilization of LAB volatiles in a strain-dependent manner.

SUMMARYThe African fig fly, Zaprionus indianus Gupta, is a widely distributed polyphagous drosophilid fly of tropical origin. Its occurrence in Jordan was first reported on date palms from the Central Jordan Valley in June 2012. Studies on biological aspects of a fly population collected from Northern Jordan Valley were carried out under laboratory conditions at 25±1˚C, 75±10% RH, and 14 h photoperiod. Mashed banana fruits with dry active yeast of Saccharomyces cerevisiae were used for the first time as a diet for larval and adult stages. The data obtained showed that the average mating period was 2.5 days, the preoviposition period 2.7 days, the oviposition period 42. 7 days, incubation period 24.5 h, hatching of eggs was 91.7%, duration of larval stage 7.4 days, pupal stage 6.8 days, adult male life span 42.2 days, adult female life span was 37.7 days. The larval stage had the highest mortality followed by the pupal stage and then the egg stage. The life cycle lasted 13.9 to 23.2 days with an average of 17.9 days. Emerged adult flies showed a sex ratio of 1.0. The obtained results provided basic data that may help in the management of this pest in Jordan.