Effect of organic sources of nutrients on development of Thrips tabaci lindeman (Thripidae: thysanoptera) in onion

Laboratory experiments were carried out to study influence of organic sources of nutrients on developmental biology of the Thrips tabaci Linde man (Thripidae: Thysanoptera) at Tamil Nadu Agricultural University, Coimbatore during 2009–2010. The nymphal period shortened by 2 days on plants receiving NPK alone, whereas extended by 4 days in the treatments viz., NPK + FYM + biofertilizers + neem cake and NPK + vermicompost + biofertilizers + neem cake. Few nymphs got transformed into pupae due to the treatment: NPK + FYM + biofertilizers + neem cake. Minimum survival (50%) was attained in treatment NPK + FYM + biofertilizers + neem cake. Highest nymph settling response was found when NPK alone was applied.