STUDIES ON SOME PIERCING-SUCKING INSECT SPECIES INFESTING CERTAIN OIL CROPS IN EGYPT

Abstract

Three piercing-Sucking insect groups i.e, aphids, leafhoppers and whiteflies were studied on three oil seed crops in Egypt namely soybean, sunflower and peanut at Seds Agric. Exp. Res. Station, Beni­ Suef Governorate during two successive years 1996 and 1997.

Surveys of different piercing-sucking insect species were

•conducted in three localities namely Beni-Suef•. Fayoum and Mounfia

Governorates throughout one season, 1996.

Population densities and seasonal abundance of aphids, jasside and whiteflies and their associated predators on soybean. sunflower and peanut were estimated throughout two successive seasons (1996 and 1997).

Biological aspects of Bemisia Iabaci on three host plant species were conducted under glass-house conditions, i.e. duration of immature stages, total duration of immature stage, percentage of apparent and intrinsic mortalities duration of adult stage (pre-ovipostion, ovipostion and post-ovipostion periods), fecundity, longevity of male and female and sex ratio.

Some agricultural practices, such as effect of planting date and effects of adding mineral fertilizers, nitrogen and potassium on the population densities of piercing-sucking insects infesting the three oil seed crops were studied.

Key words: survey, biology, population densities. agricultural practices, sowing dates, mineral fertilizers, aphids, leafhoppers, whiteflies, soybean, sunflower and peanut