Spodoptera frugiperda (Lepidoptera: Noctudiae) is an insect pest that attacks many crops around the world and causing large reductions in the crop yield, including Graminaceous crops, especially maize. This pest introduced Egypt from Sudan, was recorded for the first time in Egypt in 2019 at Aswan Governorate on corn plants, and recently recorded in Assiut Governorate in 2021. In this study, the presence of S. frugiperda was detected in the Nile Delta of the northern part of Egypt, since it was transferred from the Upper Egypt governorates. Identification was made by observing the symptoms of infection on the investigated corn plants and the morphological characteristics of insect stages, such as holes on leaves and stems with larval feces, and presence of a white Y-shape on the head and 4 crescent-shaped black spots on all abdominal segments, except for the eighth segment, where they are square shaped. Further, the pupa has a pair of straight thorns at the end, while the adult insect has a row of small scales near the apical margin of the wing and the color of the wing changes from grayish brown to rusty brown. This study proves the presence S. frugiperda in northern part of Egypt, and because this pest has been detected, identified and its dispersal and crop destruction has been confirmed in many governorates of Egypt, it is necessary to update the geographical maps of its local distribution, to apply the recommended control approaches as a way to minimize its impacts on the agricultural crops. Further studies on its biology, host range, and food preference have to be taken in account.

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The present laboratory study focused on studying the biology of a recent invasive insect pest in Egypt, fall armyworm; Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) on leaves of two host plants, maize and castor bean. This pest species has recently invaded Egyptian fields causing unexpected damage to maize crop, so, biology of S. frugiperda was studied under laboratory conditions to estimate its larval instar durations, total larval period, pupal weight, pupal duration, adult emergence%, sex ratio, male and female longevity and fecundity. Obtained results showed that mean incubation period of egg were 2.75 and 3.06 days, while larval durations were 16.26 and 22.03 days and pupal duration lasted 9.93 and 10.40 days, respectively, after rearing on maize and castor bean leaves, respectively. Means of total egg production were 1836.67 and 1562.33 eggs/female by rearing on these two hosts, respectively. Pre-oviposition; oviposition and postoviposition periods were 3.36, 6.77 and 2.20 days, for females fed during larval stage on maize leaves, opposed to 4.97, 5.80 and 2.50 days when reared on castor bean leaves. Adult longevities were longer by feeding larvae on castor bean leaves than on maize leaves. Also, results indicated that FAW growth indices were higher by feeding on maize leaves than on castor bean leaves. So for rearing S. frugiperda, maize leaves may be used as preferred, but castor bean leaves can be also, successfully used in case of the absence of the former host plant.