The cecidomyiid Endaphis sp. is a locally common endoparasite of the aphid Euceraphis gillettei on alder in coastal British Columbia. The midge represents the first known protelean parasite of aphids that may develop gregariously inside the host. Field and laboratory observations are presented on the parasite’s life history and host instar preference. Mechanisms enabling the partitioning of the available “host space” between Endaphis sp. and the aphidiid parasite Praon sp. are discussed.

Larch sawfly larvae, Pristiphora erichsonii (Hartig), naturally reject single needles of newly elongated shoots and consume only tufted foliage from 1 year or older short shoots of tamarack, Larix laricina (Du Roi) K. Koch. Forest entomologists have recognized this unusual feeding behavior for over a century, but not until now has the mechanism been understood. In the bioassasy of unpurified single needle methanol extracts (concn. 1 g needle/ml), 88.5% of the larvae were feeding on the control end of the bioassay twig (solvent only) after 4 h. This was significantly different from a similar bioassay of tufted foliage extract (t-value significant at 0.02 level) and a non-treated control bioassay (distilled water on both ends of bioassay twig) (t-value significant at 0.01 level). In the bioassay of a purified extract of single tamarack needles (TLC fraction 7), 81% of larvae were feeding on the untreated end (t-value significant 0.02). Thin-layer chromatography fraction 7, of eight fractions delineated, alone induced significant feeding inhibition.

Metopolophium dirhodum (Walker), a grain aphid, contained 25.58% dry matter, of which 31.65% was fat, 2.58% sugar, and 39.44% protein. Foliage of the host for M. dirhodum, oats (Avena sativa L.), contained one-third the amount of dry matter, less than one-third as much fat, slightly less sugar, and about three-fifths the amount of protein as M. dirhodum. Phosphorus content was the same in M. dirhodum and its host, whereas oat foliage contained five times as much potassium, and twice as much calcium and magnesium as M. dirhodum. The limiting amino acid in both grain aphid and oat foliage was methionine. Protein scores, which are estimates of protein quality, were slightly lower for oat foliage than for M. dirhodum but both are valuable sources of food for predatory insects and other animals.

Growth and survival rates for larvae and pupae of Aedes vexans (Meigen) were measured in the laboratory at constant temperatures of 10°, 15°, 20°, 25°, and 30 °C. Growth rates in all stages increased with temperature except for 1st stage larvae which developed marginally faster at 25°C than at 30°C. The shortest stage at all temperatures was the 2nd, followed in most cases by the 3rd, 1st, and 4th larval stages, and then pupae; pupae and 4th stage larvae took markedly longer to develop at low temperatures. Average survival rate was about 99% every 3 h for larvae and 98% for pupae. At 10° and 15°C, 1st and 2nd stage larvae survived no better than later stages, but at the higher temperatures survival to the 3rd stage larva was better than 90% but decreased markedly in the 3rd and 4th stages. Overall survival was highest at 25°C. Mosquitoes reared at 10°C did not pupate, while those reared at 30 °C pupated but adults did not emerge.

These laboratory data were used in a computer program whose output under field temperature regimes was compared with events in the field. The program works in 3 h time-steps. Rate of development varies with temperature and utilizes a modification of the algorithm of Stinner et al. (1975); the modification removes time as the independent variable in the development equation. Mortality rates are constant at 1% every 3 h for larvae and 2% for pupae. The program’s predictions for graduation from one stage to the next in the field population were all within about 13 h of the observed times and at the start of the pupal stage after 400 h, the output was running 13 h slow. The program appears to run slow at median temperatures below 10 °C and fast at median temperatures above 14°C. Events in the laboratory rearings are offered as possible explanations for these discrepancies. Predicted population size was close to that observed until the late 4th stage larva, from which point it deviated markedly. Pupal mortality in the field was much higher than in the laboratory.

An open arena, airflow olfactometer was developed and used to test the response of adult Cyrptolestes ferrugineus (Stephens) to various volatile stimuli. Beetles of mixed age and sex oriented positively upwind to the odor of beetles, frass, pentane extracts of frass, and pentane extracts of Porapak Q-captured volatiles from beetles or frass. Both sexes responded to the odor of beetle populations of mixed sex as well as to the odor of males, indicating that males produce a true population aggregation pheromone Only females responded to the odor of females. C. ferrugineus may utilize the aggregation pheromone in conjunction with fungal odors to locate suitable habitats.

Spatial and temporal patterns of Dendroctonus frontalis emerging from loblolly pine, Pinus taeda, were studied. Daily emergence was measured at 1.5-m intervals along the infested bole on nine trees Emerging beetles from three of the trees were collected and their sex identified. Topological estimates of daily emergence on all trees were computed and the spatial and temporal patterns of emergence were described using three and five parameter models. Emergence followed the same general pattern at each of the 1.5-m sampling intervals. Peak density of emergence occurred at ca. 0.25 of the process time span (day 7) and declined thereafter. Emergence density was highest at the 3.5-m interval and tapered gradually towards the top of the tree and abruptly towards the bottom. The process took ca. 28 days for completion. Emergence partitioned by sex followed the same general pattern as observed for the combined sexes. The cumulative sex ratio of emerging beetles was essentially 1:1 at each height interval.

Since the curves at the various height intervals were similar, emergence was described as an average process for the entire tree. The essential features of the process were retained in the average analysis. A probability distribution function defined for emergence permits calculation of the distribution of beetles from host trees provided the cumulative density is known. A frequency histogram illustrating the range in observed emergence density over a three year period was also included.

Adult populations of D. frontalis available for colonization were interpreted as a single process “allocation.” The allocation process was defined by two components, re-emergence and emergence, and had the following characteristics: (1) it is continous for each tree in the infestation, (2) it is distinct for each tree, (3) it is bimodal in intensity, and (4) the components may operate together or independently. The allocation concept was used to interpret the manner in which D. frontalis infestations have been observed to develop.

Adults of two new species of Trisetacus are described, T. strobi from foliage of Eastern White Pine and T. laricinae from buds of Tamarack.

The genus Alopecosa Simon is revised for North America. A general description for the group is given, and a key to species is presented. Seven species are represented in North America: A. aculeata (Clerck, 1757) from Alaska to Newfoundland and southward to Arizona; A. kochi (Keyserling, 1877) (= Tarentula gertschi Schenkel, 1951 syn. n., = Lycosa jollensis Schenkel, 1951 syn. n.) from southern B.C., southern Ontario, and western and northern U.S.A.; A. pulverulenta (Clerck, 1757) (= Tarentula aquilonaris Fox, 1940 syn. n.), recorded from the Nearctic on the basis of a female from Attu Island, Alaska; A. exasperans (O. Pickard-Cambridge, 1877) from the Canadian Arctic islands; A. mutabilis (Kulczynski, 1908) from northern Alaska; A. pictilis (Emerton, 1885) from Alaska to Labrador and New Hampshire; and A. hirtipes (Kulczynski, 1907) (= Tarentula hirta Kulczynski, 1908, syn. n., = Lycosa asivak Emerton, 1919, syn. n., = Tarentula hamiltoni Chamberlin & Ivie, 1947, syn. n.) from Alaska to northern Quebec.

A new species of Grylloblatta from the Coast Mountains of British Columbia and two new subspecies of Grylloblatta campodeiformis Walker from northern British Columbia are described and figured. The distribution of the species groups from the Rocky Mountain and Coast–Cascade Cordillera are indicated. An interpretation of the present distribution as a result of late Pleistocene and Holocene geological and climatic events is presented.

The palaearctic species Hemithea aestivaria (Hübner) (Lepidoptera: Geometridae: Geometrinae: Hemitheini), newly reported from British Columbia, is described, discussed and illustrated. The genus and species are new to the North American fauna.

The antiaggregation pheroraone MCH was ineffective in preventing spruce beetle infestation in felled spruce near Hope, Alaska. In October, most progeny were larvae but some were pupae and new adults. Densities of spruce beetle attacks and progeny on the shaded under side of stems were about twice those on the upper side, whereas attacks of Polygraphus rufipennis (Kirby) and Dryocoetes affaber (Mann.) on the upper side were 100 times those on the under side. Ips tridens engelmanni Swain was present in only 2% of bark samples. Entomophagous insects were scarce; only Medetera sp. and Coeloides sp. were found. Spruce beetle progeny were 45 times more abundant than attacking parents. Factors affecting the efficiency of sampling spruce beetle attacks and progeny are discussed.

Mean durations (±S.D.) of zebra caterpillar larvae, Ceramica picta (Harris), stadia 1 to 6 were 3.5 ± 1.0, 2.9 ± 1.6, 3.3 ± 1.2, 3.0 ± 1.4, 3.4 ± 1.3, and 7.2 ± 1.1 days when fed sugarbeet foliage and reared at 27 °C. Mean lengths and weights of caterpillar larvae are presented for each day of development. Mean male pupal weight was 333.5 ± 34.4 mg and mean female pupal weight was 362.9 ± 53.0 mg. Fecundity is correlated with pupal weight. Foliage consumption increases in proportion to larval age, weight, and length. Mean total foliage consumption for instars 1 to 6 was 0.55 ± 0.27, 1.49 ± 0.82, 4.61 ± 2.98, 14.4 ± 8.50, 40.32 ± 14.55, and 210.88 ± 54.52 cm2. A method to estimate economic injury levels for zebra caterpillar on sugarbeet is discussed.

Two new species of Phytocoris Fallén are described: alpinus from Alberta and brooksi from Manitoba. Adults and male genitalia are illustrated.

Twelve female Aedes trivittatus were captured between 5 July and 8 September 1976 at Knowlton and St. Pie, Quebec Another female of this species and a male Culiseta inornata were caught on 28 September 1977 at Henryville These two species are new mentions in Quebec.

Data are presented which show that first brood codling moth larvae have a higher diapause rate (and are thus univoltine) if reared in apples crowded with other larvae than if they are reared in uncrowded apples. From this relationship, a theoretical mechanism is proposed to help explain the interaction of genetic and nutritional effects in determining the dominant voltinism strain in codling moth populations.

Oviposition and post-oviposition behavior of Telenomus fariai Costa Lima, when parasitizing the eggs of Triatoma phillosoma pallidipennis Stål, is described. Like other egg parasites T. fariai marks hosts by rubbing the ovipositor against the host and transferring a water soluble pheromone (chemical nature unknown) to its surface. Females that had never parasitized largely ignored the mark. Females that had parasitized generally did not oviposit on a marked host. The mark was fully effective for at least 3 days after being applied. The function of egg marking by T. fariai is discussed.

The conventional yellow citrus blackfly trap was tested to determine whether size, shape, and a translucent versus an opaque material had any significant influence on capture of adults. The trap shape (square, rectangle, triangle, and circle) had no influence on efficiency, though the total number of adults caught per trap had a positive correlation with its surface area. Translucent traps were more attractive to adult citrus blackfly than opaque traps. Fluorescent yellow traps with a reflectance of 550–553 nm had a greater attractiveness than yellow with equivalent reflectance.

Monoterpene production, inner bark carbohydrate concentrations, and fir engraver attacks on grand fir were monitored for 3 years following Douglas-fir tussock moth defoliation. Monoterpenes were reduced for 2 years following defoliation. Defoliation caused a reduction in total sugars the first year following defoliation and a reduction in starch the second year. Total sugars and the previous year’s starch concentrations were positively correlated with monoterpene production. The trees which produced the least amounts of monoterpenes were the ones successfully attacked by the fir engraver.

Traps were used to monitor the emergence and seasonal activity of apple maggot flies, Rhagoletis pomonella (Walsh), in unsprayed habitats, and in selected commercial blocks and farms in the New York apple pest management program to determine the need and timing of control sprays. An average of 69, 43, and 43% fewer sprays and 71, 47, and 57% less insecticides were applied for apple maggot control, respectively, in single blocks monitored in 1976, 1977, and farms monitored in 1977, than in representative orchards in the same areas using regular commercial control schedules.

Dosage–response relationships of seven insect growth regulators (IGRs) to last instar western spruce budworm, Choristoneura occidentalis Freeman, were determined by topical application, spray application, and diet incorporation bioassays. Mortality was defined as failure to emerge as a viable adult. In spray application experiments, four IGRs—ZR-512, ZR-619, ZR-1662, and Ro 10-3108—had LD50s of less than 70 g/ha (1 oz/acre). Relative lethal effectiveness, based on a simple model combining data from the three bioassays, was ZR-1662 > ZR-619 > ZR-512 > Ro 10-3108 > ZR-777 > ZR-587 > ZR-515. We concluded that several IGRs, applied to a population consisting primarily of last instars, would induce lethal effects at dosages comparable to dosages of several conventional insecticides.