THE RELATIONSHIP BETWEEN THE IMMATURE STAGES OF SPODOPTERAL LITTORALIS AND PREDICTION OF THE FIRST GENERATION ON COTTON

Document Type : Original Article

Authors

1 Plant Protection Department, Faculty of Agriculture, Zagazig University, Egypt

2 Plant Protection Research Institute, Agricultural Research Centre, Dokki, Giza, Egypt

Abstract

The population density of immature stages (larvae 4. pupae) of .S.littoralls in clover fields was determined monthly from November to May during 1981-1992 seasons. 1.The number of immature stages of SJittorafis in clover fields during 1981-1992 showed that there were clear differences in population density between seasons and months according to the variation in environmental conditions. Also, it was found that number of immature stages of cotton leafworm was high in autumn (November and December) in clover fields where the moths prefer to lay more eggs than in cotton fields. 2.In winter (January, February and March) the insect population obvi‌ously decreased. 3.During Spring (April and May) the population of immature stages in‌creased gradually in April while in the following month of May the highest number was reported. The calculated number of April represents the true number ob‌tained through the investigated years. According to the true number of immature stages of cotton leafworm per clover field in November, it can be predicted with the level of ground stages in clover during May and subsequently the level of infestation of the first generation on cotton during June can be predicted. 4.From the relation between the number of immature stages during Ma‌rch, April and May and the number of egg-masses in cotton field in June during 1982-1992 seasons using partial regression, it was

Files

Share

How to cite

Statistics