Status of Bemisia tabaci (Gennadius) in Context of its Biology and Ecology in Cotton Agroecosystem

Cotton is an important cash crop and extensively cultivated in different parts of the world. Many factors are responsible for its low productivity and production but the magnitude of insect pests that damage cotton crop from sowing to maturity, is most important. Introduction of Bt cotton lead to drastic reduction in bollworms incidence but sucking insect pests such as whitefly, mealybug, jassid and thrips aphids has increased. Among these, whitefly, Bemisia tabaci is most serious pest of cotton. At present, it is globally distributed and known to infest several plant species. It causes damage to cotton crop by direct feeding and contamination of lint by honey dew and sooty mould. It transmits a deadly cotton leaf curl virus. B. tabaci has strong relationship with abiotic factors like temperature, humidity and precipitation. Temperature has positive correlation and relative humidity has negative correlation with whitefly. A combination of temperature and relative humidity is highly important for its multiplication in cotton. For a multi-voltine and multi-crop pest like B. tabaci estimating rates of mortality in the field is extremely complex and difficult. So, life table studies are important to predict pest outbreaks and to develop pest management strategies.