Botanical insecticides on Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae) and its parasitoids in string beans cultivated in a plastic greenhouse

Abstract

The string bean (Phaseolus vulgaris L.) is one of the most cultivated vegetables in plastic greenhouses in the central region of the state of Rio Grande do Sul. Liriomyza huidobrensis (Dip.: Agromyzidae) is one of the most important insect pests occurring in this culture. This research was conducted to evaluate the effect of aqueous extracts of plants and the commercial product DalNeem on L. huidobrensis and its parasitoids, as well as to analyse the population fluctuation of L. huidobrensis and parasitoids of this insect pest. The experiment was carried out on string beans cultivated in a greenhouse, where in each of the four central lines of culture, five plots were established with five plants per plot. The experimental design was random blocks with four replications. DalNeem was the treatment that best controlled L. huidobrensis. On the other hand, the treatments did not affect the parasitoids Chrysocharis bedius (Hym.: Eulophidae) or Opius sp. (Hym.: Braconidae). In plants without the use of these treatments, the population of L. huidobrensis exhibited a sharp decline with the increase of the parasitoids C. bedius, Opius sp., Eucoilinae (Hym.: Figitidae) and Diptera.

Keywords

• Azadirachta indica
• Chrysocharis bedius
• Mosca-minadora
• Phaseolus vulgaris L.
• Plantas inseticidas