EFFICACY OF SOME PLANT EXTRACTS AND THE COMMERCIAL BIOCIDE, DOLPHIN ON POTATO TUBER WORM, Phthorimaea operculella (ZELLER.) (LEPIDOPTERA: GELECHIIDAE) UNDER FIELD AND STORAGE CONDITIONS

Field and laboratory experiments were conducted at Aga district ,Dakahlia Governorate during two successive seasons 2009 and 2010 to evaluate the efficiency of some plant extracts (demises ) and plant oils(mint oil- fennel oil -cumin oil) in comparison with the biocide (dolphin )against Phthorimaea operculella(Zeller.) . The obtained results showed that the mint oil was the most effective against P. operculella larvae (74.2, 75.9%), followed by fennel oil (62.7, 74.2%) ; cumin oil (62.6, 69.1%) and demises plant extracts (61.5, 60.5%). While, dolphin caused a relatively high mortality rate of PTM larvae( 82.6 81.4 %) during2009 2010 seasons. The results indicated that the bioactivity of the tested materials were concentration-dependent, whereas, the inhibition rates of moths resulted from eggs or pupae or moths infestation increased obviously with the rise of concentration. Meanwhile, the bioactivity of all were relatively the most to moths infestation all tested materials than eggs and pupae.