The tachinid parasitoid Chetogena scutellaris (Wulp) was reared from southern armyworm, Spodoptera eridania (Cramer), a new host record. When reared in cabbage looper, Trichoplusia ni (Hübner), (a new host) and in fall armyworm, Spodoptera frugiperda (J. E. Smith), in the laboratory, C. scutellaris developed successfully ca. 30% of the time. Success of parasitism depended on the numbers of eggs...

1. In the AÊ land islands of SW Finland, the parasitoid Cotesia melitaearum (Wilkonson) is a specialist on the Glanville fritillary butter ̄y, Melitaea cinxia (L.), which uses two host plants, Plantago lanceolata (L.) and Veronica spicata (L.). 2. Extensive survey data on the butter ̄y and parasitoid populations collected in 1994±97 were used to examine possible associations of parasitoid coloniz...

Plants attacked by herbivorous insects emit volatile compounds that attract predators or parasitoids of the herbivores. Plant fitness increases when these herbivorous insects are parasitized by solitary parasitoids, but whether gregarious koinobiont parasitoids also confer a benefit to plant fitness has been disputed. We investigated the relationship between parasitoid load of the gregarious Co...

Under commercial poinsettia production conditions we compared two patterns of parasitoid release for the aphelinid whitefly parasitoid Eretmocerus eremicus Rose and Zolnerowich. We compared the currently used pattern of a fixed weekly release number (3 females per plant per week) to an experimental pattern in which more parasitoids were released early in the crop (wks 1-8), followed by a lower ...

Discrete-time models are the traditional approach for capturing population dynamics of a hostparasitoid system. Recent work has introduced a semi-discrete framework for obtaining model update functions that connect host-parasitoid population levels from year-to-year. In particular, this framework uses differential equations to describe the hosts-parasitoid interaction during the time of year wh...

We investigate the effect of parasitoid phenology on host-parasitoid population cycles. Recent experimental research has shown that parasitized hosts can continue to interact with their unparasitized counterparts through competition. Parasitoid phenology, in particular the timing of emergence from the host, determines the duration of this competition. We construct a discrete-time host-parasitoi...

Chelonus inanitus (Braconidae) is a solitary egg-larval parasitoid which lays its eggs into eggs of Spodoptera littoralis (Noctuidae); the parasitoid larva then develops in the haemocoel of the host larva. Host embryonic development lasts approx. 3.5 days while parasitoid embryonic development lasts approx. 16 h. All stages of host eggs can be successfully parasitized, and we show here that eit...