Abstract

Laboratory studies were conducted to evaluate the contact toxicity of spirotetramat 150 OD against honeybees in Tamil Nadu Agricultural University, Coimbatore during 2007 - 2008. Spirotetramat 150 OD at 45, 60 and 75 g a.i.ha-1 caused 3.33, 10.00 and 20.00 per cent mortality, respectively to Indian bees after 6 HAT, and it increased to 10.00, 16.67 and 30.00 per cent, respectively after 24 HAT. But chloronicotinyl compounds, imidacloprid and acetamiprid and conventional insecticides, monocrotophos and methyl demeton caused increased mortality of 46.67, 43.33, 56.67 and 63.33 per cent, respectively. Similar trend was observed in Italian bees, little bees and stingless bees. Hence, spirotetramat was considered to be relatively safer to honeybees than imidacloprid, acetamiprid, monocrotophos and methyl demeton.

Keywords: Honeybees, spirotetramat, safety, chloronicotinyl, tetranic acid