The Evaluation of Damage Caused by Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) on Cucumber Grown in Glass Greenhouse

摘要

The damage on cucumber ( Cucumis sativus L., F1 Kamaron) production caused by Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) was estimated in a glass greenhouse during the year 1999. Thirty two cucumber plants were separated in four groups; each group consisted of eight plants, which per two were covered with large cages made of muslin. 0, 5, 20 and 35 female adults of F.occidentalis were released correspondingly on every plant of these four groups. The thrips were released and grew up freely. The results of this research showed that, as the population of the thrips increased, it was observed an important decrease in the number of cucumbers per plant, the cucumber length, the cucumber mean weight and the total production per plant (kg). Initial thrips number consisted from one-day old adult females, resulted in linear correlated damages to all the production parameters studied.