Exochus atlanticus sp. n., Melo & Penteado-Dias, and Trieces broadi sp. n., Melo & Penteado-Dias, are described and illustrated in Brazilian fauna. The genus Exochus and the species E. ablatus, E. izbus, T. azipas, T. riodinis, T. wardae, T. upermia and T. wascia, are recorded for the first time from Brazil. Diagnosis and distribution information for each species are provided.

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Ancistrocerus waldenii waldenii (Viereck 1906) is newly recorded from West Greenland. This is a new northern limit for the species.

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...

BACKGROUND Orussus minutus is an uncommonly collected parasitoid sawfly known from the eastern United States. NEW INFORMATION We report specimens Orussus minutus Middlekauff, 1983, from Arkansas, Iowa, Minnesota, and Manitoba, which represent new state and province records and significantly expand the known range of the species west from previous records; provide collection information for un...