The species of the genus Hyppa Duponchel are revised and a new species is described. Adults of all species are illustrated, as are male and female genitalia where known. A neotype is designated for Hadena ancocisconensis Morrison. The concept of Hyppa contrasta is modified from that of a southern Appalachian endemic to that of a common transcontinental species.

Mature larvae of Gonioctena leprieuri (Pic) and Gonioctena aegrota (Fabricius) are described and illustrated for the first time, based on specimens collected on Genista spp. (Fabaceae) in Spain. A key to known larvae of subgenus Spartoxena Motschulsky is provided. Diagnostic characters for the identification of species within this subgenus are shape of labrum, arrangement of microtrichia of epipharynx, shape of tarsal claws, and numbers of tubercles on abdominal segments. Notes on distributions and host plants are provided.

The species of the genus Entomacis Foerster in North America north of Mexico are revised. Nineteen species (12 new), including 8 species of the Holarctic-wide perplexa species group, are keyed, described, and figured. These taxa are E. ambigua (Brues), E. apopkaensissp. nov., E. arcticasp. nov., E. cellariasp. nov., E. cepasp. nov., E. eorariasp. nov., E. floridana (Ashmead), E. grandiclavasp. nov., E. longii (Ashmead), E. mellipetiola (Ashmead), E. parambiguasp. nov., and perplexa group members E. californica (Ashmead), E. microbipunctatasp. nov., E. notioxerasp. nov., E. oulasp. nov., E. parvasp. nov., E. perplexa (Haliday), E. sapratasp. nov., and E. subemarginata (Ashmead). Hemilexodes canadensis (Harrington) is synonymized under Entomacis mellipetiola (Ashmead) (syn. nov.). The status of Entomacis latipennis (Ashmead), E. filiformis (Ashmead), and Hemilexis jessei Mann is reviewed. New character complexes, particularly chaetotaxy, are emphasized for Diapriidae species taxonomy.

Hymenopterous parasitoids of filth flies (Diptera: Muscidae) were surveyed during 2 years on dairy farms in Ontario and Quebec near Ottawa, Ontario, using freeze-killed sentinel house fly (Musca domestica L.) pupae and naturally occurring fly pupae collected on site. Musca domestica and Stomoxys calcitrans (L.) (stable fly) represented 98.3% of the natural fly hosts from which parasitoids emerged. Muscidifurax raptor Girault et Saunders, Nasonia vitripennis Walker, Pachycrepoideus vindemiae (Rondani), Spalangia cameroni Perkins, S. nigra Latreille, Trichomalopsis viridescens (Walsh), and Urolepis rufipes (Ashmead) (Pteromalidae) were recovered from both sentinel and natural fly pupae. Another eight species, S. drosophilae Ashmead, S. endius Walker, S. haematobiae Ashmead, S. nigroaenea Curtis, S. subpunctata Förster, Trichomalopsis dubia (Ashmead) (Pteromalidae), Aphaereta pallipes (Say) (Braconidae), and Phygadeuon ?fumator Gravenhörst (Ichneumonidae), were recovered only from natural pupae. Over the 2 years, M. raptor comprised 90.7% of emerged parasitoids from sentinel pupae but only 17.0% of emerged parasitoids from natural pupae. From natural pupae, S. cameroni, S. nigra, and S. nigroaenea collectively comprised 60.3% of emerged parasitoids; P. ?fumator comprised 13.5% and the remaining nine species 9.2%. The recoveries of S. endius and S. nigroaenea represent new distribution records for Canada, and several new host records are identified based on structure of the host fly puparium. The parasitoid fauna is compared with that known for western Canada, and recommendations are made for both regions concerning potential natural enemy enhancement for filth fly control.

In past field studies, the greatest response of western balsam bark beetles, Dryocoetes confusus Swaine, to traps was obtained with blends of (+)-exo-brevicomin and (+)- or (±)-endo-brevicomin, which imitate the natural male-produced aggregation pheromone. We conducted a trapping experiment comparing low-release enanti ospecific blends (9:1 (+)-exo-brevicomin:(+)-endo-brevicomin or 9:2 (+)-exo-brevicomin:(±)-endo-brevicomin released at 0.3, 0.1, or 0.03 mg per day) with the standard commercial (±)-exo-brevicomin bait released at 1.2 mg per day. Multiple-funnel traps baited with the experimental blends caught more D. confusus than the unbaited traps, but only traps with the 9:2 (+):(±) blend released at 0.3 and 0.03 mg per day caught significantly more male and female beetles than those baited with the standard bait. Thus, trap sensitivity can be improved with the addition of (±)-endo-brevicomin. The sympatric bark beetle D. autographus Ratzeburg was captured in significant numbers in traps baited with (±)-exo-brevicomin. A subsequent trapping experiment showed that D. autographus responded to (+)- or (±)-exo-brevicomin, but not to (−)-exo-brevicomin, suggesting that (+)-exo-brevicomin is the principal aggregation pheromone component in this species.

The cabbage maggot, Delia radicum (L.), is a serious pest of cruciferous crops in temperate regions of North America and Europe. The effects of undersowing rutabaga, Brassica napus L. subsp. rapifera Metzg. (Brassicaceae), with white clover, Trifolium repens L. (Leguminosae), on second-generation cabbage maggot and its natural enemies were studied in Newfoundland in 1997 and 1998. In 1997, totals of 1311 and 724 eggs were recovered from bare and undersown plots, respectively. More eggs were present in bare plots than undersown plots on various specific dates. In 1997, rutabagas from bare plots weighed more than those from undersown plots, although damage ratings were similar, suggesting that competition, not cabbage maggot feeding, caused the yield differences. In 1998, there were few cabbage maggots present and little damage or yield reduction in either treatment. Similar numbers of cabbage maggot pupae were extracted and reared from each treatment in each year. In 1997, of the pupae reared from undersown plots, 48% produced cabbage maggot flies, 14% produced parasitic Hymenoptera, and 8% produced Aleochara bilineata Gyllenhal (Coleoptera: Staphylinidae); 19% of the pupae from bare plots produced cabbage maggot flies, 8% produced parasitic Hymenoptera, and 36% produced A. bilineata. More A. bilineata were captured in pitfall traps in bare plots than in undersown plots. The effect of clover on carabid beetles was species specific. There were more Bembidion lampros (Herbst) and Amara bifrons (Gyllenhal) in bare plots in 1997, and more Pterostichus melanarius (Illiger) in undersown plots in both years. Despite consistently lower egg numbers in undersown plots than in bare plots, the numbers of pupae in the two treatments were similar at the end of the season. We speculate that this may be due to differential, density-dependent mortality of immature stages of cabbage maggot caused by predators and parasitoids.