Influence of weather parameters on population fluctuation of scale insect, Aulacaspic tubercularis (Newstead) in mango

The weekly survey was conducted on scale insect Aulacaspic tubercularis (Newstead) (Diaspididae: Hemiptera) at Indian Agricultural Research Institute, mango orchard and J.P Nagar orchard during the year, 2011–12 from 32^nd standard meteorological weeks (SMW) to 8^th standard meteorological week to assess the impact of weather influence on mango scale insect infestation. The scale insect, A. tubercularis both soft and armored scale species are common pest of mango crop, which deteriorate the quality and quantity of mango. Weather is an important parameter and changing weather will alter the distribution, abundance and management of mango scale insect. On the basis of iterative approach between weather and mango scale insect the favorable weather condition for high pest infestation were weekly mean maximum temperature 32–35°C, mean minimum temperature 24–26°C, mean morning relative humidity 85–95% and mean evening relative humidity 70–85%, respectively in both mango orchard. The buildup of mango scale insect showed a positive correlation with mean maximum temperature (r= 0.66), mean minimum temperature(r=0.81), mean relative humidity at evening (r=0.58) whereas negatively correlated with mean morning relative humidity (r= -0.02) at IARI, mango orchard. In J.P Nagar orchard, mango scale insect showed positive correlation in all weather parameter such as mean maximum temperature (r=65), mean minimum temperature (r=67), mean morning relative humidity (r=65) and mean evening relative humidity (r=62), respectively. The main focus of current research survey was to assess the favorable weather condition and correlation between weather and mango scale insect for prediction the pest severity and avoid the excess application of insecticides to protect mango crop from infestation of the pest.