Effect of Entomopathogenic Nematode and Fungi on Mortality and Development of Spodoptera frugiperda (J. E. Smith) Larvae

The present study was conducted to evaluate the efficacy of entomopathogenic nematode, Steinernema carpocapsae Weiser and three entomopathogenic fungi (Metarhizium anisopliae (Metschn.) Sorokin, Trichoderma harzianum Rifai, and T. viride Pers.) against the second and fourth larval instars of Spodoptera frugiperda (J. E. Smith). The results showed that S. carpocapsae caused a pronounced mortality to second and fourth larval instars of S. frugiperda using a leaf dipping method at ۴ days post inoculation (dpi) with LC۵۰ values of ۵۲.۰۳ and ۴.۱۱ Infective Juveniles (IJs) mL-۱, respectively. On the other hand, the three tested entomopathogenic fungi caused a strong toxicity on larval instars of S. frugiperda. The fungus, T. harzianum, displayed the highest insecticidal activity on the second larval instar (LC۵۰= ۱.۱×۱۰۷ spores mL-۱) and M. anisopliae on the fourth larval instar (LC۵۰= ۱.۵×۱۰۷ spores mL-۱) after ۱۰ dpi. Our results showed that S. carpocapsae completely inhibited pupation and adult emergence from treated larvae at ۲۵۰ IJs mL-۱. The lethal effect of entomopathogenic nematode and fungi against S. frugiperda larval instars indicates that these biological control agents could be useful candidates in integrated pest management programs for this invasive insect.

کلیدواژه ها:

Fall armyworm ، Metarhizium anisopliae ، Steinernema carpocapsae ، Trichoderma harzianum.