Telenomus remus Nixon is an egg parasitoid used against fall armyworm, Spodoptera frugiperda (J. E. Smith), in various countries of the Americas. The feasibility of rearing T. remus at lower cost and greater efficiency on a novel host, Ephestia kuehniella Zeller, was addressed in a two-part study. The first part of the study compared acceptance of eggs of E. kuehniella, fall armyworm, and E. kuehniella with a kairomone from the accessory gland of fall armyworm females. Acceptance was assessed as residence time on eggs and parasitism rates. Females of T. remus spent more time and showed higher parasitism rates on eggs of fall armyworm followed by those of E. kuehniella with kairomone, and E. kuehniella. The second part of the study compared the suitability of eggs of fall armyworm versus eggs of E. kuehniella for development of T. remus. Suitability was assessed by comparing various fitness components between parasitoids reared on fall armyworm and E. kuehniella. Compared to T. remus reared on eggs of fall armyworm, those reared on eggs of E. kuehniella had longer egg to adult developmental times, shorter longevities, and reduced egg loads and adult sizes. In contrast, significant differences were not evident in levels of fluctuating asymmetry (lengths of hind tibiae and distances between apices of stigmata and hamular folds of forewings) between T. remus reared on eggs of fall armyworm or E. kuehniella. Longevity was not significantly correlated with adult size, or the correlation was poor, whereas egg load and adult size were significantly correlated in females reared both on fall armyworm and E. kuehniella.
Novel partiti-like viruses are conditional mutualistic symbionts in their normal lepidopteran host, African armyworm, but parasitic in a novel host, Fall armyworm