High correlations between food consumption and excretion in terms of dry matter, calories, lipids, and nitrogen were obtained during the larval stages of Pseudaletia unipuncta (Haw.). The regression coefficients for this relationship in terms of dry matter did not differ significantly from those of calories; this leads to the hypothesis that the ratio of food consumption and excretion in terms of dry matter in a particular larval instar provides an estimate of caloric intake.

The genus Bohemiellina Machulka, 1941 (type-species paradoxa Machulka, 1941) is a separate genus closely related to Aneurota Casey, 1893 (type-species sulcifrons Casey, 1893), not a synonym of the latter. The holotype of Aneurota sulcifrons Casey, 1893 has been compared with a representative specimen of Bohemiellina paradoxa Machulka, 1941.

Diagnostic characters of Euxoa albipennis (Grt.), E. lillooet McD., E. declarata (Wlk.), and E. campestris (Grt.) are discussed. Euxoa rockburnei and E. declarata californica are described as new species and new subspecies, respectively. Adults and genitalia of the constituents of the series are illustrated and a key to species is presented.

Alternating temperatures resulted in higher intrinsic rates of increase (rm) than constant temperatures within the range of temperature favourable for growth and reproduction of the pea aphid. This difference was due to slightly faster development and earlier attainment of maximum fecundity at alternating temperatures.

Preliminary mathematical models relating rm to constant and alternating temperatures are derived. These are:

for constant temperatures and

for alternating temperatures of 5°, 10°, and 15° amplitudes respectively. Average deviation between empirical and computed values is 2%. The efficacy of these models is restricted to temperatures favourable for development and reproduction of the pea aphid.

The pine candle moth, Exoteleia nepheos Freeman, poses a serious threat to plantation and ornamental pines. It mines in Scotch pine needles during the early stages of larval development and enters the bud during the first flush of spring growth; thereby destroying the trees’ aesthetic appearance and value as a Christmas tree. Heavily attacked trees are severely stunted and eventually die. Adults are active from mid-June to mid-August, ovipositing in needle sheaths or along twigs. Eggs hatch in about 10 days with larvae overwintering in the needles where high winter mortality may occur. Parasitism by Copidosoma deceptor Miller (Encyrtidae) is an important biological factor in controlling E. nepheos. Approximately 37.63% of the population in one Michigan stand was parasitized and about 80% of this was by C. deceptor. Peak emergence of the pine candle moth will occur 1060 ± 32 degree days above 52°F threshold temperature.

A sample of 205 specimens of the declarata group of the genus Euxoa was subjected to clustering, principal components, and discriminant analyses. The analyses were based largely on male genitalic characters. Only the discriminant analysis was successful in segregating the three nominal components of the group.

Continuous colonies of Chironomus riparius Meigen can be conveniently maintained in the laboratory and the swarming and mating behaviour is readily observable. Swarming is eocrepuscular and is mediated, at least in part, by light intensity and the marker stimulus. The effects of sound and volatile chemicals on the initiation and maintenance of swarming are not clearly apparent, but there is some evidence to suggest that pheromones may play a role in swarm cohesion.

Breeding sites for Simulium venustum, Simulium arcticum, Simulium pugetense, Simulium hunteri, Simulium canadense, and Simulium decorum were found in the Vancouver area. Addition of juvenile hormone analogues to the rearing water of S. decorum resulted in virtually complete inhibition of adult emergence.

Dorsal anterior abdomens of late instar larvae of Trogoderma inclusum Le Conte and T. variabile Ballion were exposed to six doses from each of three lasers. The effects were followed for 183 days after lasing. Ruby (1.6–9.5 j/cm2) and neodymium (4.3–24.9 j/cm2) lasing killed the darker T. variabile larvae at lower doses than those required to kill the paler T. inclusum larvae. Dehydration through ruptured exocuticle and denatured cuticle was the main cause of death. Carbon dioxide (2.1–12.7 j/cm2) lasing killed larvae of both species at intermediate and high doses due to denaturation, degeneration of the fat body, and inhibition of moulting.

At sublethal doses, subsequent instars bore lesions which lacked exocuticle and setae. Internally, the lesions consisted of wavy cuticle and thickened, vacuolated epidermis. These lesions were reversible because they regressed with moulting. Additional setae occurred in lesions of later instars where exocuticle had been initially lacking. In terms of irradiance, mortality, penetration, and persistence of lesions, the carbon dioxide laser was the most effective, the ruby laser was intermediate, and the neodymium laser the least effective.

Apterous Viviparous Female. Colour when alive: antenna pale on basal half; head and thorax brownish; mesothorax to abdominal segment VIII shining black; legs pale. Colour when macerated: antennal segments I and II pale brown, segments III, IV colourless with pale brown apical annuli, segments V, VI brown; head and prothorax pale brown, nearly colourless; mesothorax to abdominal segment VIII dark brown; cornicles dark brown; femora and tibiae pale brown, nearly colourless; tarsi pale brown, slightly darker than tibiae; cauda faintly fuscous.

Ephemerella uenoi Allen & Edmunds was described but not named by Ueno (1953) from a single nymph collected by the Japanese Himalayan Expedition in Nepal in 1952. Allen & Edmunds (1963) named this mayfly from Ueno's description and figure, and placed the species in the subgenus Drunella Needham.