Impact of weather variations on the incidence of mealy bug Drosicha mangiferae (Green) and leaf hopper Amritodes Amritodus atkinsoni (Lethier) in mango

Studies to evaluate the correlations between weather variations and population of mealy bug and leaf hopper in mango were carried out in district Kurukshetra during 2007-08 and 2008-09. The maximum incidence of mango mealy bugs (118.4 at the base of tree trunk and 72.8 on the tree trunk) was observed during first fortnight of March when maximum and minimum temperature, morning and evening relative humidity were 26.4 and 14.0 C, 90.3 and 53.7% respectively. The population of mealy bugs on twigs was found to be highest during second fortnight of March which coincided with the drastic decline in its population at the base of tree trunk and on the tree trunk. After second fortnight of April, males were not observed when maximum and minimum temperature, morning and evening relative humidity were 37.3C, 22.1 C, 61.6% and 18.9%, respectively. Leaf hoppers exhibited increasing trend from second fortnight of March (10.4 hoppers 10 leaves) to first fortnight of July (104.2 hoppers/10 leaves), thereafter the population decline was drastic (28.0 hoppers/10 leaves) during first fortnight of August when maximum temperature, minimum temperature, morning relative humidity and evening relative humidity were 33.8 C, 25.0 C, 86.7% and 79.4%, respectively. There was no incidence of leaf hopper before second fortnight of March and after the first fortnight of August. Incidence of mealy bugs/twig had a highly significant positive correlation with maximum temperature (0.964) and minimum temperature (0,938) and negative correlation with morning relative humidity ([long dash]0.740) and evening relative humidity ([long dash]0.910).