ON THE NATURAL ENEMIES OF THE MAJOR PESTS INFESTING COTTON IN EGYPT | ||
| Egyptian Journal of Agricultural Research | ||
| Volume 71, Issue 1, March 1993, Pages 131-138 PDF (1.91 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejar.1993.455556 | ||
| Authors | ||
| MOHAMED S. T. ABBAS; YOUSEF A. A. EL-DEEB | ||
| Plant protection Research Institute, Agricultural Research Centre, Dokki, Giza, Egypt | ||
| Abstract | ||
| Population densities of the six predators Coccinella undecimpunctata, Chrysopa carnea, Onus albidipennis, paederus alfierii, Scymnus sp. and true spiders prevailing in contton fields were studied in Fayoum Governorate from May until September, 1988. The study was carried out weekly in 5 plots treated with different insecticides and in a control plot. The poputlation densitiy of the predators was high in july then decreased gradually until the end of the season. Due to insecticide treatments the numbers of predators / 100 hills in treated plots were always lower compared with those in the control plots. Two species of parasites were found attacking the cotton leafworm spodoptera littoralis ; the egg - larval parasite, Chelonus inanitus and the larval parasite, Microplitis rufiventris. In addition, three other species of parasites were found parasitising on the pink bollworm Pectinophora gossypiella .These were Bracon brevicornis, Exirestes roborator and Apanteles sp. The cotton ophid Aphis gossipii was observed during May , August and September without parasites parasitizing upon it. | ||
|
Statistics Article View: 19 PDF Download: 11 |
||
