Biology and morphometric study of okra shoot and fruit borer Earias vitella (F.)

Investigations on biology of shoot and fruit borer (Earias vitella) on okra revealed that the freshly laid eggs were spherical, bluish green and finally become brownish. These measured 0.52± 0.02 x 0.51± 0.02 mm. The incubation period was 3.35± 0.76 days, and larval stage passed through four instars. The first, second, third and fourth instar was 2.16± 0.71, 1.43± 0.50, 2.26± 0.73 and 3.30±1.02 days, respectively with the total larval period of 9.13± 1.71 days. These were measured 1.77± 0.28, 2.60± 0.40, 6.45± 0.56 and 14.15± 2.12 mm long respectively and 0.27± 0.03, 0.36± 0.08, 1.24± 0.07 and 3.23± 0.51 mm, respectively in breadth. The pre-pupa lasted for 1.43± 0.50 days. The male and female pupa measured 9.78± 0.46 mm and 3.14± 0.31 mm, 10.14± 0.69 mm and 3.37± 0.09 mm, respectively, with duration of 7.90± 0.92 and 7.53± 0.50 days, respectively. The adult male measured 9.13± 0.41 mm in length and 21.02± 0.98 mm in breadth with expanded wings. Whereas, female 10.71± 1.14 mm in length and 22.30± 1.48 mm in breadth with expanded wings. The preoviposition, oviposition and post-oviposition periods were 1.50± 0.68, 6.00± 1.33 and 4.30± 1.53 days, respectively. The fecundity was 265.00± 86.75 eggs/ female. The total lifecycle of male was 30.51± 6.00 days, while in female it was 32.60± 5.59 days.