Vertical distribution of bemisia tabaci (Genn.) immatures and their parasitoids on unsprayed and sprayed cotton plants [electronic resource].

Includes references.

Field study of the vertical distribution of the cot/on whitefly Bemisia tabaci (Genn.) immatures and their larval and pupal parasitoidl was carried out at Sakha Agricultural Research Station, Kafr EiSheikh Governorate, Egypt during 2000 and 2001 cotton seasons. The results revealed that the highe.Yt numbers ofB. tabaci eggs and larvae were found on the upper level ofthe cotton plant during August in both seasons in the treated and untreated fields. The overall means of eggs and larvae on upper level were 166, 67, 496.2, 65.0//60 in' in 2000 and 12/.8, 37, 683 and 168.8/160 in' in 2001 on un/reuted and treated cotton plants, respectively. They represented 59.1,23.8,82 and 10.7% in 2000. and 72.5, 22./, 79.4 and 19.6% in 200i of the total immatures on upper level on untreated and treated callan plants, respectively. For pupae, the highest numhers were found on middle and lower levels during August and September. The overall means ofpupae on middle and lower levels represented 67.1, 89.8, 39.2, 67.2% in 2000, and 73.4, 75.1, 57 and 71.6% in 2001 of the total immatures on untreated and treated cotton plants, respectively. Two parasitoid species, Eretmocerus mundus Merct.

Summary in Arabic.

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