Bionomics of spotted stem borer, Chilo partellus (Swinhoe) Crambidae: Lepidoptera on maize

Abstract

Spotted stem borer, Chilo partellus (Swinhoe) is the major pest of maize causing a huge loss to its production. The Present investigation on the biology of this pest was carried out at Entomological laboratory, College of Agriculture J. A. U. Junagadh during 2017. The females of C. partellus lay eggs in masses and the egg laying capacity varied from 283 to 314 eggs per female. Incubation period varies from 3-7 days. Hatching percentage varied from 75.10 to 89.14 per cent. The total larval period ranged from 23 to 47days. During its larval period the caterpillar moulted five times and had six larval instars. The duration of each instar varied from 4-5, 3-7, 3-8, 4-9, 3-8 and 5-11 respectively. The fully developed larva undergoes pupation in the larval tunnel with an average pupal period of 9.16 ± 1.59 days. The longevity of female moth varied from 3 to 8 days and male varied from 4 to 8 days. The average duration of life cycle of the insect is 49.3 ± 6.2 days.