Tropentag, September 10 - 12, 2025, Bonn "Reconciling land system changes with planetary health"

Performance of Trichogramma spp. on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) eggs at laboratory

¹Agricultural Research Corporation (ARC), Crop Protection Research Center, Sudan
²Julius Kühn Institute (JKI), Federal Research Institute for Cultivated Plants, Inst. for Biological Control, Germany

Abstract

The fall armyworm (FAW), Spodoptera frugiperda (Smith), is a significant pest threatening crops like maize across Africa. Globally, measures to combat S. frugiperda have predominantly relied on chemical interventions, yet the effectiveness of such methods is waning due to the development of pesticide resistance, necessitating sustainable pest management alternatives. The genus Trichogramma has gained widespread recognition for its application in managing Lepidopteran pests across various crops. This study evaluates the efficacy of five Trichogramma species as biological control agents against FAW egg under laboratory conditions. Freshly collected eggs of the FAW, obtained from a laboratory rearing at the JKI, were exposed to adults of the various Trichogramma species. The number of parasitized eggs on filter paper (10 per replicate) were counted as soon as they turned black as indication of successful parasitism. The number of adult Trichogramma that hatched from a single FAW egg was also determined. Results showed that the parasitism rate was 86.7 % for Trichogramma achaeae, 73.3 % for T. bourarachae, 73.3 % for T. dendrolimi, 73.3 % for T. nerudai and 76.7 % for a species originally collected from Tunisia (T. spp (Tunisia)), respectively. The number of adult Trichogramma emerging from a single FAW egg was found to be 2.6 wasps for T. achaeae, 2.6 wasps for T. bourarachae, 2.6 wasps for T. dendrolimi, 2.2 wasps for T. nerudai and 2.5 wasps for T. spp (Tunisia). The study also included an experiment in which different number of eggs of FAW were exposed to adults of two Trichogramma species. Results here showed that the parasitism was 59.0 % for T. bourarachae and 97.6 % for T. spp (Tunisia) on average. In another experiment in which two-day-old eggs of FAW were exposed to adults of Trichogramma spp, the observed parasitism was 56.7 % for T. bourarachae and 100 % for T. spp (Tunisia). In general, the results indicated that all tested Trichogramma species were able to successfully parasitize the FAW eggs. Their potential use in integrated pest management programmes to control FAW infestation should be further investigated.

Keywords: Biological control, IPM, parasitism, Spodoptera frugiperda, Trichogramma spp

Contact Address: Hayder Abdelgader, Agricultural Research Corporation (ARC), Crop Protection Research Center, P. O. Box 126, Wad Medani, Sudan, e-mail: abdelgaderhyahoo.com