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ECOLOGICAL STUDIES ON CERTAIN HOMOPTEROUS INSECTS INFESTING BROCCOLI PLANTS AND THEIR ASSOCIATED PREDATOR INSECTS AT SHARKIA GOVERNORATE, EGYPT

Hashem M.S نويسنده , Abd-elsamed A.A نويسنده , saleh a.a نويسنده

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ECOLOGICAL STUDIES ON CERTAIN HOMOPTEROUS INSECTS INFESTING BROCCOLI PLANTS AND THEIR ASSOCIATED PREDATOR INSECTS AT SHARKIA GOVERNORATE, EGYPT Field experiments were carried out in broccoli fields at Minia El – Kamh, district, Sharkia Governorate, to investigate the seasonal abundances of certain homopterous insects (aphids, leafhoppers and whitefly) and their associated predatory insects during the two successive years 2006 / 07 and 2007/08. In addition, evaluated the effect of temperature and relative humidity on the population densities of these insects under field conditions. Obtained results revealed that aphid species were: Brevicoryne brassicae (Linnaeus) , Myzus persicae (Sulz), leafhopper species were : Empoasca decipiens (Poali) , Empoasca decedens (Poali) , and Balclutha hortensis (Linds.), the white fly was Bemisia tabaci (Genn.), also six predator species were found associated with these insects. These predators were: Coccinella undecimpunctata L. , Cydonia vicina isis Gr., Paederus alfierii (Koch.), Scymnus syriacus(Goeze) , Chrysoperla carnea (steph.) and Metasyrphus corollae F.. Population density of immature stages of B. tabaci occurred with two peaks at the end January and February in 2006/07 season and mid January and February in 2007/08 season. At the same time, there was one peak of adult stage in mid February in 2006/07 season and two peaks by the end of January and February in the second season. Two peaks for B.brassicae and M. persicae by the end of December and February in the first season also two peaks by mid December and February in the second season. Two peaks for E. decipiens were found by the end of November and February in the first and second seasons, respectively also two peaks for E. decedens were recorded by mid of December and February in both seasons. Occurrence of B. hortensis occurred only with one peak by the end November in the first and second seasons. One peak for predatory insects was found by mid March in the 2006/07 season, also one peak in the second season at end of February. Statistical analysis showed that temperature and relative humidity were significant with some insects and insignificant with the others. Keywords: Myzus persicae, Brevicoryne brassicae, Empoasca.decipiens, Empoasca decedens, Bemisia tabaci, Predators, Sharkia ,Egypt.

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