A Latin square design field experiment using treatment, site, and occasion as main effects was set up in spring 1981 to assess the responses of Trypodendron lineatum (Olivier) and Gnathotrichus sulcatus (LeConte) to traps baited with the pheromones lineatin and sulcatol alone and in combination with each other and with ethanol plus α-pinene. Addition of sulcatol to either lineatin or lineatin plus ethanol plus α-pinene resulted in significantly reduced catches of T. lineatum. Addition of ethanol plus α-pinene to sulcatol or lineatin resulted in significantly greater catches of both sexes of G. sulcatus and T. lineatum. These results suggest that separate traps be set out for each species in mass trapping suppression programs in timber processing areas and that ethanol and α-pinene be included with the pheromone to maximize catches of both of these ambrosia beetle species.

The species Dytiscus vittiger Gyllenhal, 1827 is transferred from the genus Agabus Leach sensu lat. to Ilybius Erichson. The species is recorded from the western arctic regions of North America for the first time. A full description of the species and comparisons with other North American members of the genus are provided.

The genus Oethecoctonus of North America is revised. Three species are recognized, of which two are new to science: O. ophrynopus and O. pleuralis. O. oecanthi (Riley), the type-species of the genus, is redescribed and figured. A generic diagnosis of Oethecoctonus and key to North American species are given. The higher classification and world distribution of Oethecoctonus species are discussed.

Eighteen piercing and sucking insects were identified as feeders on green pods of mustard crops, Brassica juncea (L.) Coss. in Saskatchewan. Of these, the false chinch bug, Nysius ericae (Shilling), Lygus spp., and the western damsel bug, Nabis alternatus Parshley, were found to carry the yeast Nematospora coryli Peglion internally. N. ericae was capable of transmitting this organism to seeds in healthy green mustard plants.

The food intake of fourth, fifth, and sixth instar spruce budworm, Choristoneura fumiferana Clemens, was investigated by feeding larvae for 24 h artificial diet incorporating amaranth dye. Amaranth was selected because it followed Beer's law over a wide concentration range, mixed well with the meridic diet, could be extracted in ice-cold water, was not absorbed by larval tissue, had minimal feeding deterrence as well as marginal adverse chronic effects on the larvae, and finally had negligible effect on ingestion rate over a 24 h period. The results indicated that 6th instars consumed 20 times and 5th instars 3 times as much as 4th instars, but when compared on a body weight basis the ingestion rate was similar in all three instars. Temperature and photoperiod influenced the rate of food intake. The application of these findings in assessing defoliation to the forests as well as estimating dosage of pesticides for control of this species are discussed.

Genetic variation among western spruce budworms from 14 sites of high-density infestation in central Idaho and western Montana was examined using electrophoresis. Relationships were assessed through cluster analysis of genetic distance values and by study of shared rare alleles. Three genetically similar groupings appeared among budworms over the 14 sites. The genetic data and analysis of historical records of outbreaks over the area indicate that dispersal may play a significant role in the spread of some infestations.

Females of a European parasite, Microctonus bicolor Wesm. tested with adults of crucifer-infesting flea beetles from Manitoba, oviposited readily in Phyllotreta striolata (F.) and occasionally in Phyllotreta cruciferae (Goeze), but not in Psylliodes punctulata Melsh. Immature parasites developed and emerged from both P. striolata and P. cruciferae. M. bicolor is unlikely to provide economic control of P. cruciferae, which is the most important of the rapeseed-infesting flea beetles in the southern part of the prairie provinces. Further releases of M. bicolor should be in more northerly rapeseed-growing areas where there are higher population densities of P. striolata than at the original release site in southern Manitoba.

Directional cone-orifice traps were suitable for monitoring population densities of five Lepidoptera species, provided the captured moths were removed from the traps on a regular basis of at least once a week throughout the flight period. Omni-directional traps with circular screen barriers in the entrance area and a slow-release insecticide in the receiver to kill the captured moths functioned well over extended periods of unattended use. These traps would be useful for monitoring and mass trapping purposes. Similar traps without the circular screen barriers were less efficient but, due to their simplicity, they would also be suitable for monitoring purposes. The optimum quantity of pheromone per dispenser was the same for the directional cone-orifice and omni-directional traps.

Empoides Vilbaste, 1968 is synonymized with Empoa Fitch, 1851, which is treated as a subgenus of Typhlocyba Germar, 1833, with 9 new combinations. The male genitalia are illustrated. The gillettei complex, consisting of 14 Nearctic species with identical male genitalia, is analyzed using 90 series taken on identified hosts. T. bella and T. unifasciata n. spp. are described from eastern Canada, and three new synonymies based on colour variation are presented: Empoa acericola Christian, 1953 and E. caryata Christian, 1953 = E. gillettei Van Duzee, 1917, and E. elmata Christian, 1953 = T. saffrana McAtee, 1926. A key to the species of the gillettei complex is included.

Populations of the bromegrass seed midge, Contarinia bromicola Marikovskiy and Agafonova, were sampled in bromegrass plots in Saskatchewan in the years 1974 to 1980 inclusive. Two peaks of midge adult numbers were observed, the first at bromegrass heading time in early June and the second about 20–25 days later at bromegrass flowering. Parasitism by a species of Tetrastichus (Eulophidae) varied from 30% to 75%. Carbofuran (0.14 kg A.I./ha) or dimethoate (0.56 kg A.I./ha) spray, applied just before emergence of adult midges at flowering time, significantly reduced numbers of midges and parasites resident in the plants in both of two field tests; a second generation of midge larvae, following invasion by midge adults, was significantly reduced by residual treatment effect in only 1 of the 2 years.

Prosimulium fuscum and P. mixtum larvae and adults may be readily separated on the basis of unique complements of electromorphs at the 6-phosphogluconate dehydrogenase locus. The species are closely related and share common electromorphs at 10 other polymorphic and monomorphic loci. Numerical analysis of 24 morphological characters from larvae shows cephalic fan ray number and the length of the postgenal bridge plus hypostomium can be used to identify most individuals to species. A possible environmental component in determination of morphotype may prevent correct identification of all larvae. Lack of utility of other characters currently used in keys to separate the species is discussed.

Simulated windrow experiments revealed that 32.0 ± 8.4% or 3rd-instar Agromyza frontella (Rondani) larvae completed development and formed puparia in alfalfa hay during field curing; 1st- and 2nd-instar larvae suffered almost complete mortality. Under a management schedule where first harvest was at 10% bloom, adult emergence was 45% higher from soil under windrowed hay than from soil under strips immediately raked. Development of A. frontella in hay being field-cured is discussed in relation to crop pest management and crop management options.

Experiments were conducted on Fraser fir, Abies fraseri (Pursh) Poir, seedlings or cut terminals. Results indicate that Oligonychus ununguis (Jacobi) responds most favorably to temperatures approximating 26 °C and to relative humidity levels approaching 50 to 60%. Developmental time, time to 50% mortality, net reproductive rate, mean generation time, intrinsic rate of natural increase, finite rate of increase, and days for populations to double were computed for each temperature and relative humidity regime. Simulated rainfall severely limits population density on Fraser fir seedlings.

This note deals with European Orthotylini species Pseudoloxops coccineus (Meyer) now known to occur in Canada. It was first discovered in Ontario 20 years ago, and is now reported for the first time. Additional distributional records are given for a European Mirini, Camptozygum aequale (Villers), first reported from the Nearctic region by Wheeler and Henry (1973). The two species were probably introduced accidentally into this country with nursery stock importations of Fraxinus excelsior and Pinus sylvestris, respectively.