Biorational approach for management of whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), on cotton crop

Whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), has become a key pest of transgenic cotton crop in Pakistan. As insecticides are losing effectiveness, there is dire need to work on microbial and bioinsecticides for early season management of whitefly. The current study was designed for the evaluation of Beauveria bassiana and Metarhizium anisopliae and synthetic insecticides against whitefly to find out their effectiveness under laboratory and field conditions. Under laboratory conditions, significantly higher mortality (74-84%) was observed in treatments of synthetic insecticides (spirotetramat, flonicamid, pyriproxyfen and buprofezin) and bioinsecticides (Beauveria bassiana and Metarhizium anisopliae) against laboratory reared whitefly populations. However, when applied against whitefly at three locations under field conditions, these products (insecticides and entomopathogenic fungi) reduced the population ranging from 14-63% for nymphs and 16-62% for adults of whitefly. Synthetic insecticides, insect growth regulators (spirotetramat and pyriproxyfen) were found effective as nymphicidal action, whereas flonicamid and diafenthiuron were better as adulticidal action. Bioinsecticides showed the least effectiveness under the field conditions. This study is the first report of field evaluation from Pakistan and would help in application of entomopathogenic fungi as alternative technique for pest management in future.