Reproductive Behaviour in Different Aged Adults of Fall Armyworm, Spodoptera frugiperda (J. E. Smith)

In insects, mating and oviposition are important reproductive behaviours that occur for a limited period in their lifecycle. The physiological age of an insect is crucial for reproductive maturity, mate selection and fitness. To study the effect of age on reproduction, an experiment was conducted to analyse the reproductive behaviour in different aged adults of Spodoptera frugiperda (J. E. Smith). The copulation duration varied significantly in different aged adults, with the highest duration of copulation (161.42 ± 16.53 min) in 1-day male (DM) x 3-day female (DF) mating combination and the lowest (85.00 ± 14.31 min) in 4 DM x 4 DF combination. A significant difference in fecundity, hatching percentage (fertility) and oviposition period was observed among the different mating treatments. Fecundity showed a decreasing trend along with the increasing age of the adults, with the highest fecundity (1769.60 ± 181.24 eggs) from 2 DM x 1 DF combination and the lowest (682.86 ± 82.04 eggs) from 4 DM x 4 DF mating combination. Overall, irrespective of male and/or female, an increase in age negatively impacted reproductive fitness. Therefore, any technique that delays the S. frugiperda breeding, such as pheromone-mediated mating disruption, might successfully control the pest. Practically our research information will be useful for the effective behavioural management of S. frugiperda by developing techniques like mating disruption strategies, thereby affecting its reproductive succession.