A.K. Choudhary, P.K. Amrate and A. Chatterjee
Abstract
Population data of sugarcane leaf hopper, Pyrilla perpusilla and its natural enemies, i.e., Tetrastichus pyrillae Craw and Epiricania melanoleuca Fletcher were investigated at AICRP on Sugarcane, Zonal Agriculture Research Station, Powarkheda, Hoshangabad, Madhya Pradesh, India for six year (2007-12). During 2012, an unusual incidence of pyrilla, i.e., up to 17.0 individuals per leaf (summer) and 25.60 individuals per leaf (rains) was recorded, which was 16.37 and 17.58 higher than averaged pyrilla population of 2007-11. T. pyrillae and E. melanoleuca activity was also higher and recorded up to 55.88 per cent and 5.33 viable cocoons per leaf (summer) and 81.16 per cent and 14.87 viable cocoons per leaf (rains), respectively. Seasonal meteorological parameters revealed that the winter was prolonged during 2012 and average minimum temperature up to March was 2.54oC lower than of 2007-11, this encourages better crop canopy and survival of carry over population of pyrilla during hot summer and ultimately resulted in unusual incidence during 2012. The population of 2007-11 revealed that pyrilla and its natural enemies remained low during first phase (summer). During 2nd phase (rains), the peak population of pyrilla (13.49 per leaf), was observed at 35th SMW, whereas T. pyrillae (56.75 per cent) and E. melanoleuca (13.64 cocoons per leaf) at 36th SMW, respectively. The meteorological parameters revealed that temperatures ranges from 24- 31oC, relative humidity from 65 to 97 per cent and interrupted rainfall is most suitable for built up of peak pyrilla infestation in sugarcane.