Generation Study of Fall Armyworm, Spodoptera frugiperda (J. E. Smith) under Laboratory Condition on Maize

Aims: To understand its life stages and biological parameters for planning effective strategy for control measures to harness better yield and maximizing the profit. Place and Duration of Study: Department of Entomology, C. P. College of Agriculture, SDAU, Sardarkrushinagar in India during kharif, 2023-24. Methodology: The eggs were transferred into Petri dishes and were examined for hatching. After hatching, thirty larvae were reared individually and fed on fresh maize leaf bits which were changed daily. These procedures of rearing adults and larvae were repeated during the whole year and annual generations of the fall armyworm were observed. Results: Total nine generations of fall armyworm were recorded during one year on maize. The incubation period was recorded as 2-3, 2-4, 3-4, 3-5, 3-5, 3-4, 2-3, 2-3 and 2-3 days, larval period was noticed as 15-19, 17-22, 18-24, 23-35, 19-27, 16-23, 13-20, 11-17 and 14-19 days, pupal period was 8-12, 8-14, 10-15, 16-22, 13-17, 8-14, 8-12, 7-10 and 7-12 days and adult longevity was recorded as 4-8, 5-9, 5-12, 6-14, 4-10, 3-8, 3-6, 3-5 and 4-7 days in 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th and 9th generation, respectively. The length of first, second, third, fourth, fifth and sixth instars larvae were 1.63 ± 0.06, 2.78 ± 0.20, 6.77 ± 0.25, 15.10 ± 0.33, 21.23 ± 0.75 and 31.26 ± 0.67 mm, respectively. The breadth of corresponding instars were 0.23 ± 0.01, 0.35 ± 0.01, 0.90 ± 0.01, 1.92 ± 0.01, 3.26 ± 0.08 and 3.90 ± 0.22 mm, respectively. Total life cycle of S. frugiperda was recorded as 32-40, 35-42, 38-45, 56-68, 43-54, 32-45, 28-39, 25-34 and 30-37 days, in 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th and 9th generation, respectively.