Biology and biometrics of fall armyworm, Spodoptera frugiperda (J.E. Smith) on fodder maize

Abstract

Hlk178672758">The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an extremely polyphagous insect pest that can severely impact the yields of different types of maize, namely grain maize, sweet corn, baby corn and fodder maize. FAW can cause significant losses to fodder maize, which is critical for the animal feed industry. Considering the importance of this pest on fodder maize, an experiment was conducted to evaluate the biology and biometrics of S. frugiperda under laboratory conditions and results revealed that the mean incubation period, larval duration, pupal duration, total developmental period, adult longevity of females, adult longevity of males, and total life-cycle duration of females and males when reared on R1-R6 stage of fodder maize were 2.58±0.01, 15.30±0.11 (with instar durations of 2.20±0.12, 2.70±0.004, 2.51±0.06, 2.98±0.17, 1.91±0.01 and 3.00±0.03 days for instars I-VI), 7.76±0.15, 25.64±0.02, 8.74±0.04, 7.05±0.02, 34.38 plusmn;0.03 and 32.69±0.008 days, respectively. The egg hatchability, percent pupation, growth index and adult emergence were 84.30±0.40 percent, 77.12±1.96 percent, 5.04±0.03 and 87.44±0.74 percent, respectively when reared on R1-R6 stage of fodder maize. The pre-oviposition, oviposition and post-oviposition periods were 2.16±0.03, 2.76±0.01 and 3.92±0.007 days, respectively on R1-R6 stage of fodder maize. The mean fecundity was 695.30±8.34 eggs per female and the male-to-female sex ratio was 1:1.28 and when reared on R1-R6 stage of fodder maize. The results on biometrics of S. frugiperda evidenced that the mean measurement of larval head capsule length, larval head capsule width, larval body length, larval body width and larval weight of S. frugiperda on R1-R6 stage of fodder maize varied from 0.14 to 2.91 mm, 0.12 to 2.64 mm, 0.62 to 30.2 mm, 0.13 to 2.79 mm and 1.57 to 419.7 mg for I, II, III, IV, V and VI larval instars, respectively. The average length, width and weight of pupae measured to be 12.09 mm, 3.79 mm and 291.18 mg, respectively.