Biology and Management of Mango Mealy Bug, Drosicha Mangiferae (Green)

Abstract

The present investigation on Biology and management of mango mealy bug, Drosicha mangiferae (Green) was carried out for two consecutive years during 2004-05 and 2005-06 in order to explore the biology and developing better management option against this pest on mango. Mango (Mangifera indica L.) is the king of fruits from tropical world. India ranks third in mango production in the world. Uttar Pradesh is the main mango growing state in India, sharing about 34% of total mango production having the largest area of 0.27 million hectare. All parts of the tree are attacked by different insect pests, leading to direct or indirect losses in fruit yield depending on their severity of attack, which affects the production drastically. More than 400 insect pests have been listed attacking this king of fruits. Out of these, mango mealy bug, D. mangiferae is the most important sucking insect pest causing damage at various stages of mango crop in an overlapping manner. The female bug lays eggs in the soil in many egg sacs. The nymphs hatch and crawl up to the tree and suck the vital sap from tender parts including leaves, twigs and inflorescence resulting in poor fruit setting. The mango mealy bug, D. mangiferae comes under the order Hemiptera, Family Margarodidae (Coccidae), in which complete metamorphosis (e.g., egg, nymph, pupa and adult) is found in male life cycle whereas in case of female, incomplete metamorphosis (e.g., egg, nymph and adult). In another series of experiments, efforts were made to evolve effective method for preventing ascent of young nymphs, which were made to evolve effective method for preventing ascent of young nymphs, which soon after hatching start climbing the tree trunk. Polythene sheet 30 em wide (400 guage) was proved to be the most effective barrier in preventing the ascent of mango mealy bug nymphs. There was a predator found to be very encouraging, a single predator could devour on an average as many as 10 second ins tar nymphs or 6 third instar nymphs per day. The data show that chemical insecticides, viz. imidacloprid 17.8 SL @ 0.015%, dimethoate @ 0.005%, monocrophos 36% SL @ 0.04 and chlorpyriphos @ 0.05% gave effective control even at the lower dosages. The bio-efficacy of NSKE @ 5% and Beauveria bassiana @ 1.0 x 109 cfu/ml was also fairly satisfactory.The minimum avoidable loss was recorded in imidacloprid @ 0.005% leading to higher profit margin of Rs. 375,200/ha. Thus, the cost benefit ratio (C: BR) was high in all the treatments except imidacloprid 17.8 SL @ 0.005% (1 : 20.90). It was followed by dimethoate 20 EC@ 0.05% (1 : 17.49), monocrotophos 36% SL@ 0.04 (1 : 15.65), methyl parathion@ 2% (1 : 14.62), chlorpyriphos 20EC@ 0.05% (1 : 13.59), NSKE@ 5% (1 : 10.75), B. bassiana @ 1.0 X 109 cfu/ml (1 : 14.39), ozoneem@ 0.15% (1 : 9.40), due to their high cost.