Studies on the population dynamics of Bemisia tabaci Genn. (Homopt., Aleyrodidae) in Cukurova, Turkey
1989
Oezguer, A.F. (Cukurova Univ., Adana (Turkey). Faculty of Agriculture) | Sekeroglu, E. | Ohnesorge, B. | Goecmen, H.
Populations of adult B. tabaci were studied by aid of sticky yellow traps and populations of immatures on leaf samples as well as on the foothills of the Taurus mountains as in different crops in the Cukurova plain. The investigations yielded the following results: the bulk of the B. tabaci population hibernates outside the Cukurova plain on the foothills on Cistus spp. which are the main winter hosts. In spring, from April onwards B. tabaci migrates into the cultivated area. Fields which are situated near the hibernation sites are infested first and in relatively highest density. Fields located farther off follow with a delay of 2-5 weeks. Several vegetable - e.g. potato, watermelon, cucumber - and weeds - e.g. Convolvulus sp. and Xanthium pensylvanicum - are used by B. tabaci as spring hosts. Cotton is colonized directly from the winter host. There was no relationship between the severity of cotton infestation and the distance between cotton fields and fields of spring crops. Apparently B. tabaci does not need the presence of spring crops in order to cause severe outbreaks in cotton. Population density remains low until end of July as well in cotton as in other crops, thereafter it starts to increase. This increase coincides with the closing of the canopy and repetitive irrigation. In August-September large numbers of adults are present throughout Cukurova as well on the foothills. During this time, the main oviposition on the winter host starts
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