Bioassay of five leaf extracts against Petrobia harti Ewing (Acari: Tetranychidae)

Abstract

The report has been made to find the effect of leaf extracts of five different medicinal plants on ovicidal activity against Petrobia harti Ewing (Acari: Tetranychidae) infesting Oxalis corniculata L. through bioassay under laboratory conditions at 25±5°C, 65±5% relative humidity (RH) and a photoperiod of 12:12 (L:D). Monocrotophos (36wsc) was used as a chemical standard, causing 0.35% of egg mortality. The leaf extract of Clerodendron inerme and Tagetes erecta at 1.5% concentrations registered mean mortality of 92.50% and 82.63% respectively on P. harti. The ovicidal activity of Azadirachta indica extract was most effective on hatching of eggs than others and Cymbopogon martini extract was less effective in comparison to others. This experimental report was made to find out suitable alternatives for pest control purpose. In this regard the use of botanical pesticides are appearing to be good alternative and quite promising.