cotton whitefly life cycle
When feeding on cotton at 30Â°C, a life cycle is completed in 17 days, whereas in the field development and fecundity vary according to host plants and season, and can last 25-70 days. Chemical control: Tobacco whitefly populations in Egypt and Israel have developed high levels of resistance to most currently-used pesticides, including organophosphates, pyrethroids and insect growth regulators. Cotton and tomato are especially damaged in the Middle East. Common names: Tobacco whitefly; cotton whitefly; sweetpotato whitefly; silverleaf whitefly. The IGR’s job is to break the cycle by stopping the nymphs from becoming … Anonymous, 2004. Their overall effect (especially in the field) may sometimes be limited due to the rapid development of the pest which often overtakes that of its enemies. Adults (but not the feeding nymphs) suffer heavy mortality during khamsin periods, and development ceases below 12Â°C. Plant resistance: Certain tomato cultivars suffer fewer attacks than others, probably due to a thick coat of glandular trichomes. Females live for a fortnight in summer, several months during winter, producing 80-300 eggs. This has led to the implementation of a resistance-management program in Israel, within which the use of pesticides with different modes of action is rotated during the season in cotton fields. EPPO Bulletin 34: 281-288. Steve Francia, Gerling, D. and Mayer, R.T. (Eds) 1996. Dynamics of biotypes B and Q of the whitefly Bemisia tabaci and its impact on insecticide resistance. 1994, Managing resistance in Bemisia tabaci in Israel with emphasis on cotton. However, little information is available on the impact of most of these predators under field conditions. To complete its development the pest requires 225 to 370 day-degrees. El Kady, H. and Devine, G.J. Host plants: These pests have a wide host range, occurring on more than 500 plant species assignable to over 60 plant families. Dispersal between plants in the field or for long distances is by drifting on winds. Intercept, Andover, UK. Studies on biology of cotton whitefly, Bemisia tabaci were carried out under screen house conditions on cotton (variety H-1117 and hybrid RCH 134 BG II). 227-415. 2003. Otherhost plants include weeds, which often serve as alternate hosts when commercial crops are not available. It is estimated that since 1991 annual crop value losses exceed $500 million in the USA alone. Advances in Virus Research 69: 249-311. Other pesticides in use are neem compounds, various oils and petroleum. Antignus, Y. All adult whiteflies are small, approximately 1.0 mm in length, with a yellow body and two pairs of white wings covered with a white waxy powder. Cultural control: Barriers, including row covers, repellent mulches (such as peanuts), screens with very fine mesh, yellow polyethylene sheets or those that absorb UV (âUV-deficientâ) can reduce infestations. A recent approach is the creation of transgenic tomato plants resistant to TYLCV. Although recognized as pests for at least 80 years, they attained major pest status only in the last two decades, possibly through the indiscriminate use of pesticides. and Brown, J. K. 1999. and de Barro, P.J. and De Barro, P. 2010. Several Aphelinid parasitoids in the genera Encarsia and Eretmocerus, attack the pest and often control it. As females prefer to place their eggs on the young, apical foliage, its nymphs are age-distributed vertically on the host plant, the older stages being located on the older and lower leaves. Pest survival is constrained by climatic factors. The North American form is known as Biotype A. Biotype B, the silverleaf whitefly, initially named Bemisia argentifolii Bellows and Perring, is thought to have originated in the area encompassing Sudan, Israel and Yemen, whence it invaded North America. style based on spf13 A practical guide to identifying members of the Bemisia tabaci species complex: And other morphologically identical species. The Hebrew University of Jerusalem, This site is Pesticide Science 42: 113-122. USDA, ARS, Beltsville, USA. Ultraviolet-deficient greenhouse environment affects whitefly attraction and flight-behavior. 2014. In addition, it is the only whitefly vector of geminivirus virus diseases, reducing yield of certain crops by 20-100%. Bemisia tabaci. At rest the wings are held in a Î (inverted V) position. They differ from each other by causing different plant disorders, by transmiting different virus diseases, by supporting different parasitoids, by different flight patterns and by molecular markers. 2014. Insecticide resistance in Egyptian populations of the cotton whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae). Horowitz, A.R., Forer, G, and Ishaaya, I. Some entomophatogenic fungi infect B. tabaci, but their overall effect in the field or in greenhouse is not known. Due to the excretion of honeydew plant leaves can become sticky and covered with a black sooty mold.
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