The effect of temperature on development of the carrot rust fly, Psila rosae (F.), was determined at constant temperatures in the laboratory. The relationship between rate of development and temperature was essentially linear from 10° to 17.5°C but began to diverge from linearity between 17.5° and 20°C. Estimated threshold temperatures (t) and thermal constants (K) for development of overwintered pupae were 2.3°C and 319 degree-days (dd) for first emergence and 1.8°C and 368 dd for 50% emergence. For laboratory-reared stages, t and K values were 4.1°C and 102 dd for egg hatch, 2.0°C and 642 dd for development from egg to mature larvae, and 3.0°C and 107 dd for pupation. Development in the laboratory from egg (less than 24 h old) to adult was completed in 59, 70, and 81 days at 20°, 17.5°, and 15°C respectively; no threshold or thermal constant was estimated because few or no individuals completed development to adult at 12.5° or 10°C within expected times, presumably because diapause was induced at these temperatures.

Four sampling methods for Ooencyrtus kuvanae (Howard) populations were compared for efficiency using coefficients of variation. On this basis, none of the sampling methods was uniformly superior to any other, but a cluster of 0.01 ha subplots was chosen as the best method because of the aggregation of both gypsy moth egg masses and parasitoids. From the estimated population variance per egg mass it was calculated that 150 egg masses should be sampled per plot to provide an error bound of 0.2 parasitoid per egg mass (α = 0.1). An analysis of variance indicated that variation among study areas was the largest source of variation, and that among day, within day, and plot configuration variation were significant. Estimates of parasitoid activity are most reliable during the period between 1300 and 1600 h EST. Activity of parasitoids was reduced on overcast days. In August, the distribution of O. kuvanae approximates that of the negative binomial but with too many individuals in the high frequency classes. In a compromise between cost and accuracy, the sampling scheme selected consists of thirty 0.01 ha subplots per plot sampled between 1300 and 1600 h EST on sunny days. This sampling scheme was found satisfactory using field evaluation.

A 5-year study of a bivoltine strain of the European corn borer, Ostrinia nubilalis (Hübner), showed that first-generation moths deposited more eggs on early-planted corn, whereas second-generation moths oviposited more frequently on late-planted corn. The second generation was much larger than the first generation and caused the greater reduction in yield, regardless of whether the yields were based on physiological losses or a combination of physiological losses and dropped ears. It was shown that delay of harvest beyond the time that moisture content of the corn was sufficiently low for machine harvesting could result in severe yield losses from broken stalks and dropped ears during autumn storms.

The alfalfa blotch leafminer, Agromyza frontella (Rondani), typically develops through three complete generations a year. It overwinters as a partially developed pupa that completes its development in mid-May. Three distinct adult flight periods occur: mid-May to mid-June, late June to late July, and early to late August. Eggs are deposited singly in alfalfa leaflets beneath the lower epidermis and on hatching, the larvae move toward the upper leaflet surface where they feed on the mesophyll and develop through three instars to form blotch mines, each representing about 27% of the leaflet area. The mature larvae emerge from the mines and drop to the soil to form light brown puparia, mainly in the top 2.5 cm of soil.

Duration of each stage decreased with rise in temperature up to 25° but none of the stages survived 30°C. Developmental rates plotted against temperature gave highly correlated linear relationships for all stages. The theoretical threshold for the egg, larva, and pupa was 7°, 3°, and 4°C, respectively; thermal requirements for these stages were 55, 123, and 333°D, respectively.

Survival of the larvae was higher in leaflets with solitary mines than in those with multiple mines; only 25% of the leaflets with two mines gave rise to two mature larvae. Three larvae seldom survived in a single leaflet.

A thermal summation model based on heat units above 9°C accurately predicted peak hatch of eggs, an event critical to management of the alfalfa weevil, Hypera postica (Gyll.), in southern Ontario. The model also gave accurate predictions for maximum numbers of the larval and pupal stages, as well as other significant events such as cocooning and adult emergence.

A blacklight trap was established at 3790 m in 1978 and at 3505 m, 3657 m, 3790 m, and 3810 m, in 1979, on the alpine tundra in Colorado. Weekly catches from 6 July to 4 August 1978, and 26 June to 14 September 1979, resulted in ca. 3500 individuals of over 48 species of moths. These results establish that a greater diversity of moths exists and greater nocturnal flight activity occurs than was previously supposed for alpine tundra communities. The implications for pollination and insect foraging are discussed.

The wheat bulb fly, Delia coarctata (Fallén), a widespread Eurasian species, is recorded for the first time from Quebec, New Brunswick, Prince Edward Island, Nova Scotia, and Maine. Unlike most Anthomyiidae, this species overwinters in the egg stage in the soil. Hatching occurs in early spring, and young larvae attack the roots of fall-germinated grasses. The primary host is couch grass, Agropyron repens (Linnaeus). In Europe, however, D. coarctata is an important pest of winter wheat, and workers in North America are alerted to its potential economic importance here. Adults may be distinguished from other root maggot flies by a combination of characters which includes the plumosity of the arista, the setation of the thorax and legs, the colour of the wings and legs, and most importantly, the details of the male and female terminalia.

Two species of the genus Sesioplex Viereck of North America are revised. One new species, californicus, is described, the other, depressus Viereck, is redescribed. The limits of the genus are redefined and a key to adults is provided. The important taxonomic features of both species are illustrated by line drawings.

A new species of the genus Quedius Stephens, Q. repens spec, nov., is described from Oregon. It belongs to the Limbifer-group and represents the third species of this species group known from the Pacific coast area.

Additional data on taxonomy, bionomics, and geographical distribution of many species are presented.

Mature male Pseudohylesinus nebulosus (LeConte) walking on Douglas-fir logs were strongly arrested and stridulated at a female gallery or artificial galleries with female frass, but not at artificial galleries without frass. This response diminished after the female had accepted a male in the gallery. Mature males emitted distinctive chirps for stress, attraction, and rivalry, all of which were different from chirps of immature males, and pushed intruding males from the gallery. In contrast, reproductively immature adult males were only weakly arrested both at artificial galleries and those of feeding females, and were not aggressive toward other males. Only stress chirps of immature males were distinguishable from chirps in other contexts. These observations suggest that adult reproductive maturation includes development of close-range olfactory and acoustic signals and territorial behavior.

Although wood species was a statistically significant influence on percentages of eggs that hatched and larvae that tunneled into wood, these percentages were > 85% on most woods tested. Of eight test woods, yellow-poplar sapwood was preferred for egg-laying and was best for larval survival and growth. Slash pine was also favorable for egg-laying, survival, and growth. Beetles laid more eggs on Douglas-fir plywood and sweetgum than on shortleaf pine, but larvae did not survive in the plywood, and tunneled extensively without appreciable growth in sweetgum; larvae survived and grew well in shortleaf pine. The beetle life cycle is at least 2 years in favorable woods and may be 3–5 years in unfavorable woods.

On 20 April 1978, Mr. Paul Thompson, Program Co-ordinator, Food Production & Inspection Branch, Agriculture Canada, found a dead grasshopper in a meadow near the Canadian National Steamship Terminal at Port aux Basques, Newfoundland. The insect was identified by Dr. D. K. McE. Kevan, Department of Entomology, Macdonald College, Ste. Anne de Bellevue, Quebec, as an adventive male lubber grasshopper, Brachystola magna (Girard). This is the first record of the lubber grasshopper in ~ewfoundland

Multiyear benefits or carryover effects of single treatments of Bacillus thuringiensis (B.t.) have been suggested in a few reports. Morris (1977) noted that over 2 to 3 years after treatment both defoliation by and oviposition rates of the spruce budworm (Choristoneura fumiferana) were lower in B.t.-treated plots than in untreated plots. Smirnoff et al. (1974) suggested that “metabolic perturbations” in survivors of B.t. treatments affected fecundity and numbers the following year. With other insects, Ruelle et al. (1977) suggested multigenerational effects in the browntail moth, Euproctis chrysorrhoea, and Pruett et al. (1980) described an “exceptional” case with the Siberian silkworm, Dendrolimus sibericus, where over-wintering larvae harbored sublethal infections of B.t., which spread to subsequent generations.