The fall armyworm, Spodoptera frugiperda, a moth originating from the American continent, has recently invaded most African countries, where it is seriously threatening food security as a pest of cereals. The current management methods rely heavily on the use of synthetic insecticides but there is a need for more sustainable control methods, including biological control. Surveys were conducted in two West African countries, Ghana and Benin, to determine the native parasitoid complex and assess parasitism rates of S. frugiperda. Samples of S. frugiperda eggs and larvae were collected in maize fields located in 56 and 90 localities of Ghana and Benin, respectively, from July 2018 to July 2019. Ten species were found parasitizing the pest, including two egg parasitoids, one egg–larval, five larval and two larval–pupal parasitoids. The two most abundant parasitoids in both countries were two Braconidae: the egg-larval parasitoid Chelonus bifoveolatus and the larval parasitoid Coccygidum luteum. Parasitism rates were determined in three Ghanaian regions and averages varied from 0% to 75% between sites and from 5% to 38% between regions. These data provide an important baseline for the development of various biological control options. The two egg parasitoids, Telenomus remus and Trichogramma sp. can be used in augmentative biological control and investigations should be conducted to assess how cultural practices can enhance the action of the main parasitoids, C. luteum and Ch. bifoveolatus, in the field. Understanding the parasitoid complex of S. frugiperda in Africa is also necessary before any development of classical biological controls involving the introduction of parasitoids from the Americas.

Biological control is one of the best options for the sustainable management of the invasive maize pest Spodoptera frugiperda in Africa. However, there is limited knowledge of the efficacy of native natural enemies of S. frugiperda and their potential use in integrated pest management. The endoparasitoid wasp Coccygidium luteum is one of the natural enemies of S. frugiperda in Africa. This study assessed, under laboratory conditions, the effect of C. luteum on the leaf consumption rate of its host. Fifty first instar S. frugiperda larvae were exposed to C. luteum for oviposition and the maize leaf consumption rate of parasitized larvae was assessed and compared to 50 unparasitized larvae from the same cohort. Coccygidium luteum completed a generation, from egg to adult emergence, in 16.7 days. The leaf consumption rate of parasitized S. frugiperda larvae declined gradually compared to unparasitized larvae and the overall consumption reduction by parasitized S. frugiperda larvae was 89%. Our findings show that C. luteum could reduce damage caused by S. frugiperda to maize farms but, prior to its use in biological control programmes, further studies are needed to assess potential parasitism rates in field conditions and develop a cost-effective mass production system.

The life cycle of the invasive alien insect pest, fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), was studied using a colony established from field-collected larvae. Eggs, neonate larvae, and newly emerged adult moths were used in experiments to investigate the basic biology of the FAW. Adult females laid up to 1184 eggs with a mean of 46922 eggs per female. The incubation period of eggs and percentage hatchability were 2-3days and 8087, respectively. The mean larval lengths from the first to the sixth instar were 4.63, 6.60, 9.76, 15.86, 25.13, and 27.81mm, respectively. The mean larval weights were 0.003, 0.019, 0.045, 0.050, 0.060, and 0.067g, respectively, for the six instars. The mean width of the head capsule of the sixth instar larva was 2.76mm. The total larval duration throughout the six instar stages was 1618days, while the mean pupal weight was 0.250.001g and 0.350.011g for males and females, respectively. The mean pupal length was 14.30.16mm for males and 17.20.14mm for females. Pupal duration ranged from 8 to 14days, with a mean of 10.350.26days, while the pupal emergence rate ranged from 60 to 94, with a mean of 80.251.28. The life cycle of males lasted 3344days and that of females lasted 3649days under laboratory conditions. Adult copulation occurred between 8 and 11 pm, with the peak occurring at 9 pm. This study provides baseline information about the biology of the FAW. Apart from being an important reference point for future research on the FAW, the data provided would aid FAW management decision-making.