(STUDIES ON THE BIOLOGICAL CONTROL OF THE POTATO TUBER-MOTH PHTHORIMAEA OPERCULELLA (ZELLER)- (Lepidoptera : Gelechiidae

Abstract

The title :Studies on the Biological control of th•e Potato Tuber- moth Phthorimaea operculella Zeller (Lepidoptera : Gelechiidae).

The aim of this study was to throw more light on the biological control of the potato tuber moth, Ph. operculella , therefore the plan of research was as follows:

I - Survey of the different stages of the insect under field conditions.

An intensive survey was undertaken for two successive seasons (1996/1997 & 1997/1998) at El-Shohada locality, Menoufiya Governorate.

The examined vergetable crops were mainly potato (cultivars: Nicola & Diamant) crops, tomato, pepper; eggplant, and potato tuber in stores. The results of this part of study could be summarized as follows:

l-As for winter plantation of potato crop var. Nicola, the rate of infestation by the potato tuber- moth was light (10- 16 insect/ I 00 leaf) during January then it increased till reaching the highest levels during Februaey month (18 - 20 insect 1100 leaf), while the rate of infestation for Diamant variety at the same plantation was ranged between 6 - 14 insect /100 leaf.

2- As for the summer plantations (1996/1997 & 1997/1998) the rate of infestation by the potato tuber- moth was very high in comparison with winter plantation. There were a high significant differences in the two plantations for both varieties along the two experimental period, where the rate of infestation for Nicola variety ranged between 0.7- 2.54 insect I leaf and 0.9 - 2.78 insect/ leaf for two studied