Biology of chilli fruit borer, H. armigera indicated that the female laid eggs singly or in batches of 2 to 3 on tender leaf and shoots of chilli plant. Eggs were hemispherical with flat base and prominently sculptured with numerous ridges running from one polar end to another. The egg laying capacity of the female varied from 742 to 1235 eggs. The hatching percentage was 53.20. The incubation period ranged from 2 to 5 days. The average length of first, second, third, fourth fifth and sixth instar larvae were 1.60 ± 0.22, 4.57 ± 0.59, 9.55 ± 1.32, 11.98 ± 2.33, 17.71 ± 1.27 and 25.93 ± 3.70 mm, while that the average breadth were 0.26 ± 0.05, 0.68 ± 0.13, 1.16 ± 0.26, 1.83 ± 0.29, 2.70 ± 0.31 and 3.72 ± 0.37 mm, respectively. The average larval duration of first, second, third, fourth fifth and sixth instar larvae were recorded as 2.88 ± 0.73, 3.46 ± 0.51, 3.91 ± 0.79, 3.73 ± 0.70, 4.55 ± 0.51 and 4.71 ± 0.72 days, respectively. The total larval period was completed in 23.14 ± 1.28 days, when reared on chilli. The pre-pupal period recorded as 1.48 ± 0.51 days. The average length and breadth of pupa measured as12.33 ± 0.80 and 3.69 ± 0.52 mm, respectively. The average pupal period was 12.67 ± 1.28 days. The male moth was of greenish-grey while female was of orange brown. The average length of male and female measured from 16.94 ± 0.83 and 20.31 ± 1.62, while breadth with expanded wingspan measured as 33.12 ± 0.82 and 34.23 ± 1.83 mm, respectively. The sex ratio (Male: female) was 1:2.08. The average pre-oviposition, oviposition and post- oviposition periods were 2.86 ± 0.85, 8.14 ± 0.85 and 1.52 ± 0.51 days, respectively. The male and female moth lived for 8.56 ± 1.04 and 10.80 ± 1.32 days, respectively. The average longevity of male recorded as 8.67 ± 1.06 days while that of female was 10.90 ± 1.22 days. The average fecundity of the female recorded as 1048.40 ± 193.58 eggs. The total life cycle of male was completed in 40 to 59 days (48.43 ± 2.44 days), while it was completed in 42 to 62 days (50.67 ± 2.13 days) during the present investigation.