Co-existence of aphis gossypii glov. And bemisia tabaci genn. on the different parts of cotton plant as influenced by some biotic and abiotic factors [electronic resource].

Includes reference.

The cotton aphid, Aphis gossypii Glov. and the whitefly, Bemisia tabaci Genn. are among the most serious sucking insects attacking cotton plant in A. R. of Egypt. The population density of the two insects co-existing on leaves, squares and bolls as well as its relation to associated predators, temperature and relative humidity was studied at Farm of Sakha Agric. Res. Station, Kafr El-Sheikh during 2002 and 2003 seasons. The obtained results indicated that the highest numbers of the two insects co-existed during August or early September on the three parts of cotton plant and this coincided with low population of the predators. Five predatory species; Chrysoperlla carnea Steph., Paederus alferii Koch., true spiders, Coccinella spp. and Scymnus spp. were found on the three parts of cotton plant. The first predator was the most dominant species ,while the last one was the least one. The leaves exhibited higher number of the two insects and predators than squares and bolls. Aphid population was higher in the first season than in the second one, while the reverse was found for whitefly and predators. The two insects mostly correlated insignificantly and highly significantly in the first and second season , respectively. The temperature was within the optimum range for the population activity of aphids and whitefly. The effect of relative humidity on the two insects was not stable and differed from season to another. The predators ( as a total count of the predatory species) affected whitefly more than aphid especially during the second season. The combined effect of the predators and the two weather factors was more pronounced only on the whitefly population on bolls in both seasons. However, these results are of great importance for developing programs of integrated control these insects in cotton fields.

Summary in Arabic.

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