BIOACTIVITY OF SOME FORMULATIONS OF NEEM SEED EXTRACTS AGAINST THE WHITEFLY BEMISIA-TABACI (GENN)

The bioactivity of different formulations of neem seed extracts agains t the whitefly Bemisia tabaci (Genn.) was assayed in semifield trials during 1992. Tomato plants variety UC-97 were cultivated in pots and l eft to natural infestation with whitefly in an open field and sprayed with various concentrations of each extract. The high concentrations o f all the extracts tested exhibited obvious activity. Also, the differ ent treatments reduced the population density of the adult whiteflies compared with the control. The percentage reduction in the population reached its maximum level one hour after treatment with any tested ext ract.