Bio-ecology of mango fruit borer, Autocharis (=Noorda) albizonalis Hampson (Pyralidae; Lepidoptera) - a recent threat to mango growers in West Bengal, India.
Sahoo S. K., Jha S.
Author Affiliation: Malda Krishi vigyan Kendra, Uttar Banga Krishi Viswavidlaya, B.S.Farm, Ratua, Dist.-Malda, Pin - 732 205, West Bengal, India.
: 601-608
Abstract : The fruit borer, Autocharis (Noorda) albizonalis [Deanolis albizonalis], a predominating pest of mango, has recently appeared in serious proportion in the major mango growing areas of the West Bengal, India, particularly in the districts of Malda, Murshidabad, Nadia and Hooghly, causing 10-52% damage of fruits from the pin head stage to full maturity and it is likely to spread in the new areas. Field studies were conducted in West Bengal, India, during the 2003/04 cropping season, regarding the incidence pattern, bionomics and varietal preference of the pest. The insect passed through 5 larval instars in 11-13 days. The incubation, pre-pupal and pupal periods lasted for 2-3, 4.5-6 and 9-11 days, respectively. Approximately 2-3 overlapping generations were found only during the fruiting season and they passed the off-season as pre-pupae inside the cracks and crevices of the tree. Pupation was observed inside the dry branches and crevices of the bark of the mango plant. In the field, 1-3 mango fruits were damaged by a single larva. On the other side, more than one larva were also recorded in one mango seed. Longevity of the adult was 5-6 days in the female and 1-2.5 days in the male. The first generation larvae attacked the fruits during the second to third week of March and peak infestation was observed during first week of April and then population declined. The next peak infestation was observed during the second week of May, which again was followed by a decrease. Length and breadth of the first, second, third, fourth and fifth instar larvae were 4.9 and 1.08, 10 and 2, 12.3 and 2.2, 14.8 and 2.7 and 19.5 mm and 3.5 mm, respectively. Full grown larvae were with dark brown head, mandible heavily sclerotized and white body ornamented with red intersegmental bands. Wings of the adults were ashy wood in colour mixed with bluish pink metallic shine and middle portion of the fore with 2 black coloured spots. Males were identified from the female by the presence of brush-like dark brown hairs ventrally on the mesotibia and tarsus. Length and wingspan of the males and females were 14-15 and 23 mm and 10-13 and 21 mm, respectively. The fruit borer consumed both the flesh and seed of mango fruits, but preferred the seed. Damaged fruits became unfit for human consumption. Investigation regarding the preference of mango fruit borer to different cultivars showed that Langra and Fazli were most susceptible.