Effects of plant volatiles on the feeding and oviposition of Thrips tabaci
Material and Methods
Analysis of the essential oils showed the proportion of their main compounds – the monoterpenes terpinen-4-ol and 1,8-cineole (Table 1).
T. tabaci was reared in the laboratory using the bean-pod method, modified from Loomans and Murai (1997). For the assessment of the antifeedant and insecticidal properties of the volatiles against T. tabaci females leaf disc bioassays were conducted as previously described by Koschier et al. (2002).
For assessment of the oviposition rate on treated (no-choice test) or the oviposition preference for treated or untreated leaf discs (dual-choice test), respectively, 2d-old females were singly allowed to oviposit on the leaf discs for 24 hours. After this time the number of eggs on the leaf discs was recorded. Thrips rearing and all bioassay units were maintained in climate chambers at 25 ± 1°C and 65 ± 5% relative humidity with a photoperiod of L16:D8