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Triarthria setipennis is a tachinid parasitoid of the European earwig (Forficula auricularia) and following introduction from Europe has become established in British Columbia and Newfoundland, where it provides low levels of control. Populations of T. setipennis were surveyed in central Europe during 1989-1991 and individual insects reared to identify available biotypes that may be more effective than biotypes already established in Canada. Additional information is provided on parasitoid biology; this could facilitate new introduction of T. setipennis which could be used to augment existing or introduced populations in Canada for the control of F. auricularia. Microclimatic conditions and sufficient territory space for pairs are important to elicit mating activity. Older males mated readily with newly emerged females. The gestation period of mated females is on average 19 days. Triarthria setipennis is ovolarviparous and lays its eggs close to potential hosts. Chemicals are involved in the host-finding and host-acceptance response of the females. Females lay on average 235 eggs. The oviposition period lasts 4-5 days. Once a first-instar larva contacted a host, it mounted it and tried to penetrate through the intersegmental skin between the head and thorax, or on the thorax or abdomen; this process takes less than 3 min. Only 16.7% of the parasitoids manage to penetrate the host successfully. The duration of larval development is variable, taking from 2 weeks to 2 months during June and July. Most pupae were obtained during August. Overwintering occurs in the pupal stage. In Germany and in the northwestern part of Switzerland there is one full and a partial second generation per year. The first generation of T. setipennis in southern Austria shows a long emergence period and the individuals differ markedly in colour. The highest rate of parasitism in the field was 46.9%

The exotic cabbage maggot (CM) infests canola on the prairies, feeding on roots in its larval stage, which disrupts the uptake of nutrients and water and provides an entry point for fungal plant pathogens. The European staphylinid, Aleochara bipustulata L., may be introduced for control of CM, but only if the risk to other species is low and if A. bipustulata has demonstrable potential to increase mortality already caused by natural enemies in Canada. Aleochara bipustulata could contribute to pest management as a predator of CM eggs and larvae, and as a parasitoid of CM puparia; however, it could affect non-pest species in the same two ways. A variety of invertebrates that share the soil of Brassica fields with immature CM were screened in laboratory no-choice assays to determine what adult A. bipustulata eat. In these assays, immobile or barely mobile invertebrates were accepted regularly and could be at risk. The majority of groups were seldom or never consumed. Also, a molecular assay developed to test for CM DNA in the guts of field-collected A. bipustulata revealed its high potential as a predator, and a similar assay developed for two carabid beetle species showed these to be seldom if ever consumed. Laboratory and field cage assays with other CM egg predators showed A. bipustulata has potential to disrupt other species, particularly the closely related A. bilineata Gyllenhal, as they seem to forage in similar microhabitats. Measurements of field-collected beetles indicate CM is unlikely to be the primary host in Europe, so introducing A. bipustulata to Canada may bring risks to non-target Diptera species. This was observed even though a series of laboratory experiments demonstrated CM is a superior and preferred host relative to the smaller, acalyptrate cheese skipper.

As a first step towards the development of an ecologically rational control strategy against western corn rootworm (WCR; Diabrotica virgifera virgifera LeConte, Coleoptera: Chrysomelidae) in Europe, we compared the susceptibility of the soil living larvae and pupae of this maize pest to infection by three entomopathogenic nematode (EPN) species. In laboratory assays using sand-filled trays, Heterorhabditis bacteriophora Poinar and H. megidis Poinar, Jackson & Klein (both Rhabditida: Heterorhabditidae) caused comparable mortality among all three larval instars and pupae of D. v. virgifera. In soil-filled trays, H. bacteriophora was slightly more effective against third larval instars and pupae, and H. megidis against third larval instars, compared to other developmental stages. In both sand and soil, Steinernema feltiae (Filipjev) (Rh.: Steinernematidae) was least effective against second instars. In conclusion, all larval instars of D. v. virgifera show susceptibility to infection by all three nematodes tested. It is predicted that early application against young larval instars would be most effective at preventing root feeding damage by D. v. virgifera. Applications of nematodes just before or during the time period when third instars are predominant in the field are likely to increase control efficacy. According to our laboratory assays, H. bacteriophora and H. megidis appear to be the most promising candidates for testing in the field.