A field experiment was conducted at the experimental farm attached to EI-
Khanater, Horticulture Research station, Qalubia Governorate during two successive
seasons of (2000 and 2001) to study the population density of PTM in five potato
varieties Field trials were carried out to estimate the number and duration of potato
tuber moth phtbotimeee opercu/ella (Zeller) in the field and at storage. It appears that
the reliable appearance of Potato tuber moth phthorimaea opercu/ella (Zeller) moths
took place during March until June in the field but at storage appears from July to the
beginning of September .. The effect of some bioicides and Sumithion against PTM in
storage was also studied. Results obtained showed that, Most susceptible variety to the potato tuber moth (PTM) was Picasso
followed by Nicola, Agria, and Santana variety while Desira variety was the least
susceptible one. The tested compounds arranged, according to the average effect percent
reduction of infestation as follows: Sumithion, ( Granulosis virus (GV) + Dieple 2-X ),
dieple2-X and GV descendingly