Oviposition Preference of <i>Chelonus insularis</i> Females, a Parasitoid of <i>Spodoptera frugiperda</i> , Does Not Match Their Offspring's Performance

ABSTRACT Chelonus insularis (Cresson) (Hymenoptera: Braconidae) is an egg‐larval parasitoid of the fall armyworm (FAW), Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae). Previous studies reported that maize plants can affect the performance of FAW as well as that of its parasitoids. However, there is little information about whether plants affect the performance of egg‐larval parasitoids of FAW. It is also unknown whether C. insularis females can perceive cues from different maize cultivars and therefore preferentially parasitize hosts on which their offspring's performance is highest. In this study, we compared the preference and performance of C. insularis on three maize cultivars: the Mexican landrace Tuxpeño, the inbred B73 from the United States, and inbred isoline B73‐lox10, a B73 mutant deficient in the production of jasmonic acid, green leaf volatiles, and herbivore‐induced plant volatiles. Oviposition of C. insularis females and colonization preferences of FAW neonate larvae parasitized by C. insularis were assessed using three‐choice cage tests in a greenhouse. The offspring sex ratio, adult weight, development time, and longevity were used as indicators of parasitoid performance. C. insularis performance was highest on B73‐lox10 plants, lowest on Tuxpeño plants, and intermediate on B73 plants. However, females preferred FAW eggs laid on Tuxpeño plants, followed by those laid on B73‐lox10 and B73 plants. FAW neonate larvae parasitized by C. insularis preferentially colonized B73‐lox10 plants, although initially they colonized Tuxpeño and B73 plants, which were comparatively detrimental to the parasitoid's development. Overall, C. insularis females did not prefer parasitizing hosts on host plants on which their offspring's performance was highest. However, FAW larvae parasitized by C. insularis chose to colonize host plants on which the parasitoid's performance was highest. The results of this study provide information that could be useful for designing strategies for biological control of FAW.