Effects of botanical extracts on the developmental and reproductive traits of fall armyworm (Spodoptera frugiperda)

Fall armyworm (Spodoptera frugiperda) is a polyphagous pest of many crops, especially cereals, necessitating eco-friendly control strategies. The present study assessed the impact of natural plant extracts on its life-history traits. The results showed that larval mortality was highest (73.18%) when treated with Azadirachta indica oil extract, followed by Datura stramonium (63%), Eucalyptus tereticornis (45%), and the lowest mortality (12%) was observed in the control. Pupal mortality was also highest (26.66%) in treatments with A. indica oil extract, while no pupal mortality was recorded in the control group. The pre-oviposition period was longest after treatment with A. indica (6.01 days), followed by E. tereticornis (5.01 days) and D. stramonium (4.52 days). The oviposition period lasted 6.02 days with A. indica treatment, 5.19 days with E. tereticornis, and 5.02 days with D. stramonium, whereas the longest oviposition period (8.02 days) was recorded in the untreated group. The post-oviposition period was shortest with A. indica (1.58 days), followed by E. tereticornis (1.38 days) and D. stramonium (1.09 days). The adult lifespan of S. frugiperda was significantly reduced in all treatments: A. indica (10.85 days), D. stramonium (11.98 days), and E. tereticornis (13.12 days), compared to the control (14.52 days). The average number of eggs laid per female was 205.52 ± 10.52 with E. tereticornis, 180.52 ± 9.52 with D. stramonium, and 114.52 ± 10.52 with A. indica. The mean egg hatching rates were 40% with E. tereticornis, 28% with D. stramonium, and 20% with A. indica, respectively.