Environmental stresses on the egg laying capacity and survival period of a top borer, Tryporyza nivella (fab.), on sugarcane (Saccharum officinarum Linn.)

Top Borer (T. nivella) is a major ruinous pest of sugarcane. Larvae of T. nivella heavily destroy the newly growing leaves and top region of sugarcane plant. Adults of T. nivella were collected from selected sugarcane fields during experimental year; 01 April, 2012 to 31 March, 2013 for this study. After then, they were reared at different levels of humidity and temperature at laboratory conditions. To prepare the three different levels of humidity, concentrate H₂SO₄ was mixed with distilled water in three different proportions. Survival period of adults increases with decreasing humidity level. Survival period decreases with decreasing temperature range. The egg laying capacity of female adult decreases with decreasing temperature and increases with decreasing humidity. On the temperature below 20°C, the female did not lay eggs.