Beet armyworm (Spodoptera exigua) as a host for the ectoparasitic nematode, Noctuidonema guyanense

The beet armyworm, Spodoptera exigua (Hubner) (Lepidoptera: Noctuidae), is an economically important pest in the southeastern United States. An ectoparasitic nematode, Noctuidonema guyanense Remillet and Silvain (Nematoda: Acugutturidae), naturally attacks the adult stage of several Spodoptera species, but not the beet armyworm. We assessed the suitability of the beet armyworm as a host for N. guyanense in the laboratory. Nematodes of variable developmental stages were transferred from feral fall armyworm, S. frugiperda (J. E. Smith), moths to beet armyworm moths in the laboratory to test whether the latter species is a suitable host for N. guyanense. Nematodes transferred to moths of the beet armyworm became established, multiplied, and transferred to new hosts on which they reproduced as infested hosts mated. Our results confirm that the beet armyworm is a suitable experimental host for N. guyanense, and that it should be pursued as a candidate for inoculative and augmentative biological control studies in the field.