Of the three large ephydrid flies of Yellowstone’s thermal springs, Ephydra thermophila numerically dominates acidic springs because only it can tolerate their water. Alkaline spring effluents are shared by Ephydra bruesi and Paracoenia turbida. E. bruesi is excluded from alkaline high productivity springs, probably because its larval maturation time is long, relative to the short life of patches of larval habitat. Consequently, such springs support only P. turbida. Proportions of the two species in alkaline low-productivity springs are apparently determined by the proportions of available larval food occurring in still versus flowing water. P. turbida is superior in still water, and E. bruesi wins in flowing water. The analysis leads to predictions (i) that E. bruesi should be relatively abundant in low-productivity springs with pulsating flows, and (ii) that E. bruesi adults should prefer ovipositing in low-productivity effluents, while P. turbida adults should be less particular.

Choristoneura lambertiana ponderosana Obraztsov is commonly found infesting its main host, Pinus ponderosa Laws., in Colorado. It is also known from Wyoming, South Dakota, and Montana. Pinus flexilis James is a host in Montana, and in Colorado ponderosa pine dwarf mistletoe, Arceuthobium vaginatum subsp. cryptopodum Hawksworth and Wiens, is also utilized as a food plant. Adults fly and oviposit in midsummer; newly hatched larvae overwinter in hibernacula and emerge in the spring to feed on new foliage. Pupation takes place in the feeding area. There is one generation per year.

The important species of predacious ants in Europe and North America belonging to the Formica rufa L. group, and their association with forest insects, is discussed. The absence of desirable species in Quebec is stated, and a brief description of an aggressive western North American species (F. obscuripes Forel) is given. The method used in collecting large colonies of this species in Manitoba, of transportation to Quebec, and of the eventual release and establishment is described. It is concluded that F. obscuripes is increasing in number in Quebec, and should be considered as permanently established.

A method was developed to terminate pupal diapause in Rheumaptera hastata through experimentation using controlled abiotic factors. Male and female pupae exposed to 0 °C at 75–100% moisture content for 90–120 days terminated diapause within 8–19 days following treatment. This method reduces diapause by 4 months compared with natural conditions. Light had a minimum effect on diapause termination; therefore, pupae should be exposed to constant darkness during the treatment period, followed by exposure to a 20L:4D photoperiod to obtain a high percentage of adult emergence.

Adults and pupae of the Colorado potato beetle were controlled by treatment with methyl bromide at levels that did not injure new potatoes at 25°C. At lower temperatures the tolerance of the new potatoes was slightly reduced. A dosage schedule that will control adults and pupae without injury to the potatoes is given.

The V. arenaria queen was able to heat her nest shortly after it was constructed, and expended up to 550 cal per hour per gram of biomass to accomplish this. In contrast, the V. maculata colony was not heated until it was 11 days old, by which time the brood consisted of about 15–20 large larvae which probably played a major role in the heat production process. When both colonies were about 2 weeks old, energy expenditures of more than 400 cal/h could be maintained for several hours, and the nest temperature could be elevated as much as 4°C above the ambient. During these periods the larvae probably accounted for as much as 66–71% of this energy expenditure. In addition to playing an active role in heating the nest, the larvae apparently provide the queen with a food source while she is producing heat during non-foraging periods.

A rearing technique was developed to study various aspects of the biology of Zetzellia mali (Ewing) in the laboratory. The rate of development of Z. mali feeding upon the phytophagous mite Aculus schlechtendali (Nalepa) was determined at 9°±1°C and 14°±1°C (56% R.H.), 19°±1°C (33%, 56%, 76%, and 97% R.H.), and 24°±1°C (51% R.H.). The average preovipositional and ovipositional periods for 16 female Z. mali were 1.5 and 9.4 days respectively and an average of 1.7 eggs per day were laid by these females. Z. mali was found to be arrhenotokous with unmated females producing only male offspring and mated females producing 2.6 females: 1 male offspring. Diapause in Z. mali was broken at 24°±1°C, 16L:8D) with egg deposition beginning after 11 days (51% and 76% R.H.) or 12 days (33% and 96% R.H.) when the adults feed upon the winter eggs of Panonychus ulmi (Koch).

A life table was constructed for Z. mali and the intrinsic rate of increase (rm) was determined to be 0.109 female offspring/female/day. The mean generation time (T) was calculated to be 21.0 days and the net reproductive rate (R0) during this time was 10.04. The theoretical stable age distribution of the laboratory population of Z. mali at 19°±1°C, 56% R.H. was 59% eggs, 15% larvae, 7% protonymphs, 6% deutonymphs, and 13% adults.

Comparison of the intrinsic rates of increase and prey consumption of Z. mali and other species of predaceous mites indicate that Z. mali is not as efficient a regulating agent of phytophagous mites as the phytoseiids.

Mericia ampelus (Wlk.) was one of seven species of insect parasite reared from larvae of bertha armyworm, Mamestra configurata Wlk., that were collected in August 1972. At that time large populations of the host species were damaging plants of rape, Brassica spp., in numerous localities in western Canada (Wylie and Bucher 1977). As M. ampelus had not been reared before from M. configurata, studies were made in 1973–75 to determine the parasite's distribution and abundance, to obtain information on its biology and behaviour, and to assess its impact on populations of M. configurata.

The predator fauna of alfalfa, Medicago sativa L., was studied at Ithaca, N.Y., during 1966–69. Predators are separated into species that completed their life cycle on alfalfa (primary), species whose adults took prey from the plants but bred elsewhere (secondary), and species not observed to capture prey on alfalfa (incidental). Seasonal occurrences and prey records are given for the 19 primary species and the secondary species whose prey were identified.

Three species complexes (pallidiventris, chlorea, and geniculata) of Pristiphora Latreille are recognized from China. Two new species of Pristiphora from Nanking (Nanching), China, are described: P. sinensis n. sp., which is closely related to the Holarctic species P. geniculata (Hartig); and P. nankingensis n. sp., which belongs in the chlorea complex with P. fausta (Hartig), P. chlorea (Norton), and P. borneensis Forsius. P. formosana Rohwer and P. sauteri Rohwer from Taiwan (Formosa), together with P. zella Rohwer, P. pallidiventris (Fallén), and P. denudata Konow, belong in the pallidiventris complex. The lancets of the southeast Asian species of Pristiphora not illustrated by Benson (1963) are shown. Keys to adult females of species in the pallidiventris and chlorea complexes, and the separation of adult males and females of P. geniculata and P. sinensis n. sp., are presented. P. denudata is considered to be a valid species, not a subspecies of P. pallidiventris.

A Howardula sp. nematode parasite of the tobacco flea beetle, Epitrix hirtipennis (Melsheimer), was able to utilize the adult male to disseminate juveniles. At 27°C the mean total number of juveniles released per beetle was 369 for female beetles and 377 for males at an average rate of ca. 37 per day from both sexes. A cooler temperature retarded the onset of dissemination but did not affect the rate of release. Fifty-nine per cent of the free-living nematodes survived for 5–6 days, but none survived beyond 13 days. Seventy-nine per cent of the free-living nematodes were female.

Some time ago Dr. L. Masner of Ottawa sent me four female specimens of, as far as we knew, the first specimens of the genus Anopedias Först, to be seen outside Europe. He asked me to deal with them, since I had recently (1974) revised the European species.

In tests conducted in the McKinley River drainage, Alaska, seudenol combined with α-pinene attracted the most eastern larch beetles, Dendroctonus simplex LeConte. The next most attractive treatments included tamarack log sections infested with either unmated female D. simplex or unmated female Douglas-fir beetles, Dendroctonus pseudotsugae Hopkins, Neither frontalin nor trans- verbenol with α-pinene was attractive. Addition of niethylcyclohexenone (MCH) to the seudenol + α-pinene treatment repressed its attraction by 83%. Sex ratios of simplex responding to logs infested with female simplex or pseudotsugae were equal or favored females, but favored males in the case of seudenol + α-pinene. Addition of MCH shifted the sex ratio in favor of females. Two other scolytid species, Orthotomicus caelatus (Eichhoff) and Ips perturbatus (Eichhoff), were trapped, but were too few to relate to treatments. Two species of clerids were caught on traps: Thanasimus undatulus Say and Thanasimus dubius (L.); the latter is a new Alaskan record.

Characters of male genitalia and sternal coloration are used to supplement the variable characters of head shape and tegminal colour pattern in determining the species of the world Prosapia. Five new species are described: chiapana, hemelytra, ignifera, and isobar from Mexico, and fortior from Panama. One new combination is created: Prosapia miles (Fowler). Four subspecies are considered valid species: ignipectus (Fitch), inferens (Walker), ripalis Fennah (new status), and teapana Fennah (new status). P. simulons (Walker) (1858) is synonymized with fasciaticollis (Stål) (1864), and bicincta (Say) (1830) is synonymized with fraterna (Uhler) (1864). An illustrated key to males of the 14 world species is provided.

The known species of the Indo-Australian genus Heortia are reviewed. The genus and its species are characterized; its distribution and relationships are discussed; the species are keyed and figured and their genitalia are described. H. iridia n. sp., from Celebes [Sulawesi], and H. dominalis restricta n. subsp., from New Britain and Rooke Island, are described.

A key for classifying the frass of 24 species of cossid, sesiid, and cerambycid borers describes the presence, texture, form, size, and color of such frass components as excrement pellets, wood chips, finely pulverized wood, granular wood pieces, fibrous shreds, and excelsior-like shreds. Descriptions are based largely upon fresh frass produced by mid- to late-instar larvae. Host tree species, stem diameter, and portion of tree infested are used in conjunction with frass descriptions to identify the borers.

In 1975, 19.4% of 6950 marked apple maggot adults, Rhagoletis pomonella, which were released in the center of a 7 × 7 array of unsprayed apple trees were recaptured on Pherocon® AM traps. The distribution of the marked flies was not uniform as most of the flies were recaptured near the release point. The distribution of native flies which migrated into the test area from adjacent infested apple trees was also non-uniform.

Oocytes of queen bumble bees from southern Alberta were partly developed when the queens emerged from hibernation in the spring. Early emerging species had less autumnal ovariole development and fed longer in spring before establishing a nest than did later emerging species. The main increase in oocyte size was synchronous with the finding of a suitable nest. The mean length of the largest oocyte for workers for all species was small, less than 0.7 mm, clearly indicating that workers contribute few males to the population.

A method for the direct isolation of useful genetic strains was shown effective in the onion maggot. This method circumvents the extensive preliminary investigations called for by current concepts in genetic population control. From genomes treated with 1.5 kr of gamma radiation, the system showed that 17% of those tested carried chromosomal rearrangements potentially useful in genetic population reduction.

Field tests were made of the fungal inoculation method of Reid et al. which assesses the potential of individual lodgepole pine trees (Pinus contorta Dougl var. latifolia Engelm.) to resist attacks by mountain pine beetle (Dendroctonus ponderosae Hopk.). Four hundred and eighty-four trees were inoculated with one of the beetle’s mutualistic blue-staining fungi (Europhium clavigerum Robinson and Davidson), tree responses were determined, and the potential of each tree to resist D. ponderosae was predicted. Two months later, after mountain pine beetles had attacked some of these same trees, most of the predictions based on the fungal assay system proved to be incorrect. Most of the trees which were attacked and which had been rated potentially resistant did not prevent successful bark beetle reproduction. These results, contrary to those of Shrimpton and Reid, suggest that some improvement is needed in the fungal assay method of assessing resistance of lodgepole pine to mountain pine beetle. Measures of tree resistance based on success of mountain pine beetle reproduction showed no difference in the proportion of non-resistant trees between epidemic and endemic areas.