Biology of pod borer (Maruca vitrata) infesting Dolichos bean under laboratory conditions

The laboratory investigation on biology of pod borer, Maruca vitrata (Geyer) was carried out during the year 2016-17 at the Department of Agricultural Entomology, College of Agriculture, Dapoli, Dist. Ratnagiri. The laboratory studies on the biology of pod borer, M. vitrata recorded that the pre-oviposition, oviposition and post-oviposition period lasted for 3.4, 3.3 and 1.4 days, respectively. A female laid on an average 64.4 eggs singly or in batches on flower buds and tender pods. Incubation period lasted for 3.3 days with 79 percent egg hatching. The first instar larva was greenish white with head breadth 0.14 mm and body length 1.41 mm, but prior to pupation larvae changed its colour from deep white to green and pupated at the corner of petri plate. The larval development completed within 12.2 days through five instars, duration of each instar observed to be 2.3, 2.2, 2.2, 2.3 and 3.2 days, respectively. The full grown larva measured 1.6 mm in head breadth and 15.94 mm in body length. The pre pupal and pupal period lasted for 2.2 and 8.8 days, respectively. Longevity of male and female moths was 4.5 and 8.9 days, respectively. Male moth measured 11.08 mm in length, 2.15 mm in width and 24.46 mm in wing expanse. Female measured 11.90 mm in length, 2.22 mm in width and 25.32 mm in wing expanse. The sex ratio for male and female was 1: 1.17. The life cycle male and female was completed within 32.2 and 36.7 days, respectively.