A rearing method, based upon an artificial diet, has proved successful in establishing laboratory colonies of 36 species of the genus Euxoa. The diet is described, along with methods for controlling disease, particularly by the use of antimicrobial agents.Many of the 36 species of Euxoa have not been reared before and their habits and life histories are little known. The data derived from their development under laboratory conditions and which can be related to seasonal distribution are recorded. Particular emphasis is given to the overwintering stage and to the occurrence of an aestivating stage.

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), has reached outbreak status at most locations in the southern Canadian prairies. Solid-stemmed wheat, Triticum aestivum L., cultivars, which are less susceptible to damage, remain the primary management option. This article quantifies the effect of wheat stem sawfly damage on grain yield and quality at harvest and determines how cultivar selection affects harvest losses. Solid-stemmed cultivars were compared with hollow-stemmed cultivars and with blends of a 1:1 ratio of each. The hollow-stemmed cultivars with the exception of'McKenzie', which had intermediate levels of stem cutting, were all significantly more susceptible to stem cutting than solid-stemmed cultivars. Cultivar blends had lower damage but were still significantly higher than the solid-stemmed cultivars. The solid-stemmed 'AC Eatonia' and 'AC Abbey' had the lowest levels of stem cutting and ranked second and third overall for yield in 2001 and 2002. McKenzie ranked first, which reflects its yield potential in combination with its partial resistance to stem cutting. Lower cutting in AC Eatonia, AC Abbey, McKenzie, and the blend of AC Abbey/ McKenzie was significantly correlated with lower grain losses. Grain lost at harvest has major economic implications if sawfly pressure is moderate to high and susceptible cultivars predominate.

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During an outbreak of army cutworm in southern Alberta in the spring of 1990, the overall incidence of parasitism by the polyembryonic parasitoid, Copidosoma bakeri (Howard), was 61% in samples from seven fields. The incidence of parasitism in samples of army cutworms collected on five dates from a single location, during the spring of 1991, increased from about 20% in the early samples to about 50% in the later samples. Cutworms parasitized by C. bakeri feed for a longer time than unparasitized ones; therefore estimates of the incidence of parasitism by C. bakeri, based on samples of late-instar cutworms, are misleadingly high. Parasitized cutworms also grow considerably larger than unparasitized ones and may have a supernumerary instar. Larger hosts support larger broods of C. bakeri and apparently a successful strategy of C. bakeri is to prolong host development so as to maximize an acquired resource. Because cutworms parasitized by C. bakeri feed more and longer than unparasitized cutworms, a high rate of parasitism can exacerbate crop damage and complicate control recommendations. The life cycles of army cutworm and C. bakeri are asynchronous and it is likely that high rates of parasitism are dependent on the presence of intermediary hosts.

Inundative release of Trichogramma brassicae Bezdenko for control of European corn borer was tested in experimental plots in 1991 and 1992 in southern Alberta, Canada, to determine its effectiveness as a potential method of control in sweet corn. The tests were conducted in 1-ha plots, in three different fields of irrigated sweet corn each year, at a release level of about 196 000 wasps per ha. The reduction in European corn borer damage in the release plots ranged from 85 to 87% in 1991 and from 45 to 95% in 1992. The reduction in damage was not significantly different in fields with 25 and 49 release points. General area degree-day accumulation for postdiapause development was not adequate to determine the timing of release for individual fields because European corn borer phenology varied among fields. Total moth catch in pheromone traps, however, was directly related to the number of plants damaged by European corn borer, and releases near the time of peak trap catch produced the greatest reduction in damage.