EFFECT OF A NATURAL INSECTICIDE FROM NICOTIANA-GOSSEI ON THE WHITEFLYPARASITOID ENCARSIA-FORMOSA (HYMENOPTERA, APHELINIDAE)

The collateral effects of a biorational compound from Nicotiana gossei Domain on the parasitoid Encarsia formosa Gahan were determined in la boratory and greenhouse tests and compared with the effects of sprayin g with M-Pede or Margosan-O. Fewer parasitized whitefly pupae were kil led by spraying with N. gossei extract or Margosan-O than spraying wit h M-Pede. More E, formosa wasps were killed by spraying with M-Pede th an by spraying with N. gossei extract or Margosan-O and when confined to treated leaf surfaces 1 h after spraying. At 1.5 and 3 h after spra ying, both N. gossei extract and M-Pede killed more wasps than when sp raying with Margosan-O. When wasps were released into greenhouses 3 h after spraying, fewer whiteflies were parasitized on tomato leaflets t reated with biorationals than on leaflets treated with water. However, at 24 h after spraying tomato leaflets, parasitization was significan tly higher on those treated with N. gossei extract and Margosan-O. Few er wasps were found on leaflets treated with M-Pede. Although the 3 bi orational insecticides caused mortality of E. formosa, the N. gossei e xtract was less detrimental than M-Pede to the viability of E. formosa . N. gossei extract could be used successfully with E. formosa in inte grated pest management programs.