Development, reproduction and predation by two predatory thrips species Aeolothrips intermedius Bagnall and Franklinothrips vespiformis Crawford (Thysanoptera: Aeolothripidae) by feeding with two prey species

摘要

The aim of the present research study was to study development, reproduction and prey consumption by two predatory thrips species, Aeolothrips intermedius Bagnall (Thys., Aeolothripidae) and Franklinothrips vespiformis Crawford (Thys., Aeolothripidae) by feeding with two prey species, the western flower thrips Frankliniella oceidenialis (Pergande) (Thys., Thripidae) as well as the two spotted spider mite Tetranychus urticae Koch (Aeari: Tetranychidae). The experiments were conducted in the laboratory under standard climatic conditions. The results showed that A. intermedius neither developed nor the females could lay eggs by feeding on F. occidentalis larvae or T. urticae stages. On the other hand, F. vespiformis females laid a mean daily number of 0.67 eggs with both prey species. In the 18-day experimental period, the predatory females laid a mean number of 10.92 eggs by feeding on F. occidentalis larvae or 10.58 eggs with T. urticae stages as prey. The predators showed significanl differencesregarding prey consumption on F. occidentalis larvae, where A. intermedius consumed daily a mean number of 2.26 while F. vespiformis 4.71 larvae. The predator A. intermedius consumed a mean total number of 20.83 while F. vespiformis 66.50 larvae during the entire study period. There was found no significant differences between the two predators regarding prey consumption on T. urticae stages. The use of the predatory thrips F. vespiformis in Euphorbia milii plantations under actual cultural conditions resulted in significant reduction of F. occidentalis larvae as compared to control. During a seven-week experimental period after release of F. vespiformis, there was recorded only one F. occidentalis larva/flower as compared to 14 larvae/flower in the control.