Whitefly (Aleurolobus Barodensis Mask.) population fluctuations in diverse conditions of Sugarcane Crop in Medak district of Andhra Pradesh, India

Experiments were conducted in three sugarcane farmers’ fields of 10–15 kms radius in the vicinity of Zaheerabad and Ganapathy sugar factories in three locations of Medak district to evaluate the whitefly population fluctuations. The distance from one locality to another was 50–70 kms. The population of white fly nymphs and adults was recorded at fortnightly intervals during the crop season in 2006 and 2007 from April to December by randomly selecting twenty tillers/leaves from each field of an area of one hectare from each location. The data were correlated to the weather factors (temperature, humidity and rainfall). The results revealed that population of white fly(nymphs and adults) varied significantly (P <0.05) among observed intervals and locations. The whitefly appeared during the 2^nd fortnight of June in Zaheerabad and Sangareddy areas whereas it was observed in July in Medak area. The peak mean population was recorded in 1^st fortnight of August- September in Zaheerabad (7.96/leaf) and 14.94/leaf in Sangareddy area. Sangareddy area showed maximum white fly population compared to Zaheerabad area. The population reached the peak of 16.94/leaf by October. It was observed that relative humidity had positive and significant (p,0.05) correlation with the white fly population and the population increased to 42.3%, 35.9% and 43.8%in Zaheerabad, sangareddy and medak areas and the trend of white fly appearance was almost same in 2006 and 2007.