Biology of rice hispa,Dicladispa armigera(Olivier) (Coleoptera: chrysomelidae)

Abstract

Biology of rice hispa, Dicladispa armigera (Olivier) was carried out under laboratory conditions at room temperature varying between 32.98 to 23.67°C, with a relative humidity 92.86 to 84.61 per cent. The adult beetle was shiny bluish black having short spines all over the body with fecundity of 81.2± 8.83 eggs per female. Incubation period was 5.03± 0.02 days with hatching 73.98± 1.94 per cent. There were four larval instars and total larval period was 13.05± 0.23 days (11–14 days) with 85.00 per cent survival. The average pupal period was 7.05± 0.21 days. The adult male was short lived 25.10± 3.02 days as compared to female 34.70± 1.81 days. The egg was 1.00± 0.005 mm in length and 0.45± 0.006 mm in width. The larva increased in body size with age as 1.43± 0.512.62± 0.007 mm in body length, 0.31± 0.008–0.50± 0.005 mm in body width and 0.06± 0.0030.09± 0.002 mm in length of cerci of first and fourth instar larva, respectively. The overall sex ratio of male to female was 1:1.26.