FECUNDITY OF SUGARCANE TOP BORER; TRYPORYZA (SCIRPOPHAGA) NIVELLA (FAB.) AT SOME DISTRICTS OF WESTERN UTTAR PRADESH

Present investigation was carried out to study the fecundity of sugarcane top borer; Tryporyza nivella (Fab.) on sugarcane (Saccharum officinarum Linn.) at selected four sites in two experimental years. Some adults of Tryporyza nivella were collected from selected sites during first experimental year; April 2011 to March 2012 and they were released in self prepared net houses at selected sites for study. Fecundity of selected pest was carefully investigated with the help of hand lens at selected sites. Same study was carried out in laboratory conditions during second experimental year; April 2012 to March 2013 for which a sampling was made for collection of selected pest from all selected sites. In all collected insects, some healthy adults were put in polythene and transferred in plexiglass containers in laboratory and reared in B.O.D. chamber. Some pairs of healthy males and females were transferred in rearing cages for mating. The observations were closely recorded with the help of stereomicroscope with camera lucida, electron microscope and hand lens in laboratory conditions. During first experimental year, the fecundity of female Tryporyza nivella was recorded 212.75, 202.0, 208.8 and 211.45 eggs per female at first, second, third and fourth sites respectively however; the total fecundity was calculated about 215.34 eggs per female. During second experimental year; the fecundity was noted 67.4, 126.1, 142.6, 178.9 and 65.0 eggs per female at 40, 35, 32, 27 and 22 ?C in the laboratory conditions. Fecundity increased with decreasing temperature till 27 ?C than it decreased. Female Tryporyza nivella did not deposit her eggs below 22 and above 40 ?C.