Airplane application of the insect growth regulator CGA 13353, a juvenile hormone mimic used experimentally against spruce budworm, Choristoneura fumiferana (Clem.), did not drastically reduce percentage parasitism in field samples of that host, but there was some evidence of susceptibility. Exploratory sampling of maple defoliators suggested that one species and its parasitoids suffered some mortality, but another species and its parasitoids did not. The treatment did not influence the viability of ant colonies.

The new genus Archepandemis, with type-species Parapandemis borealis Freeman, 1965, is described. Two new species, A. coniferana from British Columbia and Alberta and A. morrisana from New Brunswick, are distinguished from A. borealis by characters of maculation and especially of male and female genitalia.

Pupal survival, mating, and sperm transfer in tobacco budworms, Heliothis virescens (F.), irradiated as diapause pupae, decreased proportionately with increasing doses of 3, 5, and 7.5 krad. Also, the fertility of tobacco budworms irradiated as nondiapause pupae and of the F1 progeny of such males decreased with increasing dose. When the female partner received eupyrene sperm, insects irradiated while the pupae were in diapause were fertile as were their progeny. Therefore, it does not appear plausible to irradiate diapause pupae of our strain of tobacco budworms to obtain sterile insects for a release program.

The within crown distribution of three species of Pleroneura and their food source (active buds) was determined on white fir trees 5–30 ft tall. Over 90% of all active buds and 94% of all infested buds occur in the outer half of the crown. Over 50% of the total active and infested buds occur in the middle third of the crown. Percentage infestation within the crown increases from bottom to top. Percentage infestation per tree decreases as tree size increases.

Several streams near Baie Comeau, Quebec were treated with a particulate formulation of methoxychlor (particle size 8–15 μ) or Abate® (particle size 2.5–20 μ) at a dosage of 0.1 ppm for 15 min to determine if such a formulation is effective against and selective for black fly larvae. The effects of these larvicides were evaluated by sampling the stream fauna before and after treatment with cones, Surber samplers, drift nets, and rock sampling. A new caging device, the entrapment sampler, was used to assess mortality directly.

Both larvicides were effective against Simuliidae. Neither particulate insecticide was completely selective for black fly larvae, since philopotamid larvae and some chironomid larvae were also killed. Although some other detritus-feeding insects also were affected, numerous families of insects including potential predators of Simuliidae were not affected appreciably by these particulate larvicides. Particulate Abate affected a few more families of insects than particulate methoxychlor. The comparative effects of these formulations and the corresponding liquid formulations on stream fauna are discussed. Particulate formulations are a promising alternative to the present formulations used for black fly larviciding, and further research on their safety and performance and on methods of aerial application is recommended.

Parasitic Hymenoptera are among the many insects that have been transported about the world by human agency. Unlike phytophagous pests and the parasites deliberately introduced to control them, the unknowingly introduced parasites have received little attention. Twenty Ichneumonoidea now found in Canada are listed with evidence that, with various degrees of certainty, shows them to have been unknowingly introduced from Europe.

A 4000-ha block of spruce budworm, Choristoneura fumiferana (Clem.), infested forest in western New Brunswick was sprayed repeatedly in 1975 during the larval stage of budworm development. The objective was to reduce the population of the 1975 generation to a minimum level so that most of the following generation eggs found on the block could be attributed to invading females, thus providing data on the impact of moth invasion.

The presence of dispersing adults in the airspace over the block was monitored by a ground-based radar unit while light traps and pheromone-baited traps were used to confirm that invasion had taken place. A total egg population of 33.8 masses per m2 of foliage was found on the block and indirect estimates suggest that invading females deposited about 10 of these masses.

Diapause induction studies showed that face flies, Musca autumnalis De Geer, from a recently established colony, entered diapause more readily than those that had been colonized for many years. Photoperiods of less than 16 h of light induced diapause at 16° and 27 °C but more flies entered diapause at 16°C. Maximum numbers of flies entered diapause under total darkness at 16°C, but the critical photoperiod corresponding to natural periods of daylight in late summer was 15 h of light at 16°C. Diapause termination studies indicated that 4 months’ exposure to 5 °C under total darkness was required for the termination of diapause.

Laboratory tests, at constant temperatures, were conducted to evaluate quantitatively the influence of temperature on development of the Oriental fruit moth, Grapholitha molesta (Busck). The results showed that at the highest temperature (30°C) some larvae had four instars and some had five, indicating a mixed population. Fifth instar larvae developed only at the highest temperature (30°C) where larval development was also most rapid. It can, therefore, be assumed that the Oriental fruit moth has four distinct larval instars when reared in the laboratory at 15°–24 °C.

Female budworm flight activity was monitored automatically at seven constant temperatures ranging from 10° to 25°C. Flight activity was negligible below 17.5°C, but considerable oviposition occurred as low as 15°C. It is therefore possible that during cool weather the number of insects dispersing is reduced, with the result that a larger proportion of the eggs are laid in the stand of origin.

The overwintering adult of Ooencyrtus kuwanai (How.) is susceptible to freezing. Male adults from New Jersey have a mean supercooling point of −9.6 ± 0.37°C, significantly higher than those from Maine (−12.3 ± 1.08°). Neither group had its cold hardiness increased by exposure to sublethal temperatures. Female adults from New Jersey had a mean supercooling point of −10.8 ± 0.69° when tested after rearing at 22°C, again significantly higher than that of similarly treated female adults from Maine (−15.4 ± 0.90°). Exposure of New Jersey females to sublethal temperatures decreased their supercooling point significantly, to −14.5 ± 1.59°. Maine female adults were not tested after that treatment. No adults survived continuous exposure to 0°C for 30 days. Hence this parasite is apparently incapable of surviving in the current range of the gypsy moth in Canada.

Croesia holmiana (L.) was the most common of nine species of tortricids found in 1977 in a survey of the apple leafrollers of the Vancouver, British Columbia, district. It is an European species not recorded previously from North America. Specimens from British Columbia were identified by Dr. A. Mutuura, Biosystematics Research Institute, Canada Agriculture, Ottawa.

In the past, several species of tortricid moths have been introduced in British Columbia and adjacent areas, for example: Ditula (Batodes) angustiorana (Haworth) at Victoria in 1924 (Clarke 1929: 13; Freeman 1958: 55; Powell 1964: 243); Cnephasia longana (Haworth) in Oregon in 1929 (Powell 1964: 124); Archippus oporanus (Linnaeus) at Vancouver in 1937 (Freeman 1958: 16); and Acleris comariana (Zeller) at Richmond near Vancouver in 1972 (Cram 1973: 17). These species are all of European or Eurasian origin.

A re-investigation of the taxonomic status of Bombus sandersoni Fkln. is described. Using multivariate analysis of wing venation data taken from previously identified museum specimens, a non-overlapping separation between sandersoni, B. frigidus F. Sm., and B. vagans F. Sm. was obtained. The Cresson lectotype of B. couperi appears in some respects intermediate between frigidus and sandersoni. Therefore the authors advocate retention of sandersoni as the valid name for the species, while admitting the possibility that this taxon may turn out to be a clinal variant of frigidus.

Acaronemus n. gen. is described, and its type-species, Tarsonemus destructor Smiley and Landwehr, 1976, is reillustrated. Other, undescribed species of Acaronemus are discussed briefly. Members of this genus are unique among the tarsonemid mites as known to date in preying on mite eggs.

During the course of a continuing investigation on egg structure in various insect orders by one of us (EHS), the eggs of some species of Hymenoptera became available for examination with the scanning electron microscope. In this note we report a re-examination of the micropylar region of the egg of the ichneumonid parasitoid Pimpla turionellae (L.) which was originally described by Bronskill (1959), and compare the morphological features of this region with those observed on the same region of the egg of the honey bee, Apis mellifera L. Because of their extremely thin and flexible chorions, the eggs of both species must be freeze-dried to maintain their normal shape in the vacuum of the microscope. They were glued to thin glass coverslips with a dilute solution of Scotch tape - chloroform adhesive, immediately frozen on dry ice, cut in half and freeze-dried for about 16 h at –70°C. The coverslip was mounted on a metal stub with conductive paint and gold-coated just prior to examination in a Cambridge Stereoscan MKI1A.

Winter cocoons have been described in several species of Chironomidae (summary in Danks 1971, table V; see also Madder et al. 1977). The larvae are tightly folded within these closed cocoons in ways more or less characteristic of the species. Usually the walls of the cocoons are thicker than those of the tubes within which larvae are active in summer and less particulate matter is incorporated into them. Most larvae of two species studied earlier in Ottawa (Danks 1971) constructed their winter cocoons only after surface ice had formed.

In “higher” flies (e.g. Musca dornestica L.), a pair of large air-sacs is found in the anterior region of the abdomen (Hewitt 1914). The main function of these air-sacs appears to be to maintain the extended external shape of the abdomen in newly emerged flies, because as the fat-bodies in both sexes, and also eggs in the female, grow, these air-sacs decrease in size, thus allowing room for these growing organs (Evans 1935). These air-sacs, and those elsewhere in the thorax and head, were believed to give buoyancy for insect in flight, to reduce the volume of circulating blood, and(or) increase the volume of the “tidal air” which is renewed at each respiration (see Wigglesworth 1965 for review). In our recent studies on the feeding of S. calcitrans, we noted that the change in the size of the abdominal air-sacs, besides making room for the growing abdominal organs, may minimize change in abdominal volume during feeding and digestion.