Ecological Studies on Certain Lepidopterous Insects Attacking Potato Plants at Dakhlia Governorate

Abstract

Experiments in the field conducted to evaluate population density and effect of temperature and relative humidity of five lipedoptereous insect species attacking potato plants during the two successive seasons 2017 -2018 at Meniat El-Naser region Dakhlia Governorate. The results showed that Phathorimia operculella (Zeller) had four peaks in summer plantation and the highest peak was found in the first week of May, while in the winter plantation this insect recorded two peaks and the high peak was found during 4 th week of October, during tested seasons 2017 and 2018. Data revealed that Euzophora osseatella Treitske characterized by two peaks in the two potato plantations. The results revealed that, Tuta absoluta Povolony had three peaks in each summer and winter potato plantations, respectively. The obtained data assured that Spodoptera littoralis (Boisd) had three peaks in the summer and winter plantations and the highest peak were found during late of March, throughout summer plantation and in the winter plantation during 3 rd week from September month. Three peaks during summer seasons plantation were recorded on Spodoptera exiguae (H) while in winter seasons plantation recorded two peaks during the two tested years. Population density during the tested successive years, data obtained of "temperature degrees" and "relative humidity" resulted that, the correlation degree differed from slightly positive or negative to highly significant positive.