Empoides Vilbaste, 1968 is synonymized with Empoa Fitch, 1851, which is treated as a subgenus of Typhlocyba Germar, 1833, with 9 new combinations. The male genitalia are illustrated. The gillettei complex, consisting of 14 Nearctic species with identical male genitalia, is analyzed using 90 series taken on identified hosts. T. bella and T. unifasciata n. spp. are described from eastern Canada, and three new synonymies based on colour variation are presented: Empoa acericola Christian, 1953 and E. caryata Christian, 1953 = E. gillettei Van Duzee, 1917, and E. elmata Christian, 1953 = T. saffrana McAtee, 1926. A key to the species of the gillettei complex is included.

Contact toxicities of 12 insecticides to adult Leptoglossus corculus (Say) were determined. All insecticides tested were moderately to highly toxic to adult females. Five insecticides—decamethrin, carbofuran, aminocarb, fenvalerate, and bioethanomethrin—were as toxic or more toxic than the standard, azinphosmethyl, at LD90. Decamethrin (LD90 =.06 μg/g body wt.) was 29 times more toxic than azinphosmethyl at LD90. Five insecticides—carbofuran, bioethanomethrin, resmethrin, azinphosmethyl, and chlorpyrifos—were tested on males also. The first three were significantly more toxic to females than males and the latter two were equally toxic to both sexes. All but two insecticides, decamethrin and bioethanomethrin, were equally toxic or more toxic to second-stage nymphs than adult females.

Mortality of neonatal Douglas-fir tussock moth larvae varied from 0% to 100% depending on the rearing temperature and duration of food deprivation. Lower temperatures apparently favor larval survival under starvation conditions. For each period of food deprivation, mortality occurs earlier as the temperature increases; this shift to earlier mortality was significant at P <.01. Some implications are discussed.

Among territorial syrphids, males of Eumerus tuberculatus (Rond.) are less aggressive than Merodon equestris (Fab.) and Eristalis tenax (L.) males. This difference in aggressiveness persists even when territorial pressures increase with increasing numbers of conspecifics.

Males of each species recognized conspecific females mainly by a combination of visual and behavioural cues. A territorial male might approach any intruder, but would only attempt to mate if, like the appropriate female, the intruder did not respond to the male's approach. Differences in behavioural patterns may be due to different mating strategies.

This study provides information on species of Pnigalio Schrank found in America north of Mexico: Pnigalio longulus (Zetterstedt), a Palearctic species, is recorded from the Nearctic for the first time; the previously unplaced species of Pnigalio of Miller (1970) are discussed. Seventeen species are recognized, of which the following eight are described as new: Pnigalio levis, P. brachysellus, P. elongatus, P. glaber, P. rugatus, P. neolongulus, P. boharti, and P. albiformis. A key to species, illustrations, distribution data, and host records are included.

Water added to stored wheat in the Prairie Provinces of western Canada promotes heating in the autumn and early winter. A rapid increase in a population of C. ferrugineus (Stephens) where the wheat was wet occurred after heating began and was, therefore, a consequence of the heating and not a cause.

Mandibles of females of 10 species of mosquitoes from five genera; hypopharynx of females of 26 species from 11 genera; and laciniae of females of 31 species from 14 genera, were examined using scanning electron microscopy. Mandibular teeth are present in Anopheles and Armigeres females, but absent in Aedes, Culiseta, and Culex. Interdigitating cuticular projections are present at the tip of the hypopharynx in all females examined. The salivary canal is open both at the tip as well as dorsally along a longitudinal slit. The average number of lateral teeth on the maxillary stylets varies according to species. Mesial and vestigial teeth are present in some species. There is no correlation between number of maxillary teeth and specific hosts of mosquito species. The function of stylet structure in feeding is discussed.

The validity of using 40 ± 12 degree-days (DD) above 6.7 °C summed from 1 April for predicting first spring emergence of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.), was tested. In Ontario's major apple growing areas from 1978 to 1981, the observed day of first emergence occurred 12–45 days before the predicted day. Reasons for this inaccuracy are discussed.

An alternative method, summing DDs from 1 March above a base temperature of 5.5 °C, was also tested using three methods of computation. The number of DDs accumulated to the day of first emergence and to the day of 50% cumulative emergence varied greatly between years at one location and between locations during one year. This variation is likely due to a variable relationship between air temperature and temperature in the leafminer's habitat. It is suggested that a more accurate predictive index could be developed through an understanding of the relationship between habitat temperature and weather factors such as air temperature, insolation, and snow cover.

The effectiveness of Thuricide 16B®, a water-based commercial formulation of Bacillus thuringiensis var. torstaki (B.t.), Dipel 88®, an oil-based formulation, and the Dipel® vehicle (Dipel 88 without B.t.) were compared by aerial applications against the spruce budworm, Choristoneura fumiferana (Clem.) in balsam fir, Abies balsamea (L.) stands. The two B.t. products applied at similar dosage rates were similar in effectiveness and the Dipel vehicle was not toxic for budworm larvae at rates applied Comparisons of populations of parasites made between pre- and post-spray sampling periods and between treated and untreated plots indicated no direct effect of Dipel 88 on the rate of larval and pupal parasitism.

The reproductive and demographic statistics of Aphidius smithi Sharma & Subba Rao parasitizing third-instar pea aphids, Acyrthosiphon pisum Harris, were determined under constant laboratory conditions. At host densities of 5, 10, 20, 40, 60 or 100 aphids/day, the parasite lived an average of 7 days at 20.5 °C. At host densities of ≤20 aphids/day, the total number of eggs laid and the total number of hosts attacked were limited by the numbers of hosts available. Fecundity was highest with an average of 870 eggs/female at density 100; the maximum number of eggs laid by any female was 1770. Superparasitism was common at all densities, resulting in up to 84% (at density 5) of all eggs being wasted. The relationship between host density and the number of aphids attacked per egg laid was linear for densities of ≥20 aphids/day. The intrinsic rate of natural increase (r) varied with the host density. It reached maximum value at density 100, calculated as 0.358 female/female/day and assuming an overall sex ratio of 1:1 males:females. Regression equations describing r as a function of host density and parasite sex ratio are provided. It is shown that the potential rate of increase of A. smithi exceeds that of the pea aphid over a broad range of average conditions. The parasite's functional response was convex (Holling type II) and decelerated with increasing density. The intrinsic attack rate (a′) and handling time (Th) were estimated from the functional response curve as a′ = 6.62 days−1 and Th = 0.0033 day (4.7 min). The ‘random parasite’ equation satisfactorily predicted the number of aphids attacked at each density.

The optimal release rate of the aggregation pheromone, lineatin, for trapping Trypodendron lineatum (Olivier) was 40 μg/24h. Sticky vane traps were more efficient than three other trap types for T. lineatum and Gnathotrichus retusus (LeConte). For G. sulcatus (LeConte), a multiple funnel trap was more efficient than a sticky cylinder trap but no better than vane traps or Scandinavian drainpipe traps. Placement of bait in the middle or bottom of drainpipe traps increased their efficiency in capturing T. lineatum and G. sulcatus. Multiple funnel traps and drainpipe traps releasing lineatin at 10 μg/24h, with an additional dispenser releasing lineatin at 30 μg/24h 1.5–2 m away from the trap caught more T. lineatum than traps releasing lineatin at 10 μg/24h, and were as efficient as traps releasing the pheromone at 40 μg/24h. Thus, the beetles respond strongly to the trap silhouette once attracted to its vicinity. In late April traps placed 15–25 m inside the forest margin caught more T. lineatum than traps at the margin, probably intercepting overwintering beetles before they left the forest. A few strategically placed vane traps among numerous multiple funnel or drainpipe traps are recommended for mass trapping of ambrosia beetles in timber processing areas.

The action of a formamidine pesticide on the ultrastructure of hormone release from the glandular lobe of the corpus cardiacum (CC) of the locust, Locusta migratoria (L.), has been studied. Treatment of the isolated CC with 5 μM desmethylchlordimeform (DCDM) caused depletion of neurosecretory material from the intrinsic cells of the glandular lobe without affecting the nervus corpus cardiacum II axons. Pretreatment of isolated CC with the α-aminergic antagonist (5 μM) phentolamine blocked DCDM-induced release of neurosecretory material from the glandular cells. DCDM-induced release of neurosecretion from the glandular cell axons occurred via exocytosis. DCDM treatment also affected the distribution of mitochondria. Mitochondria from adjacent cells lined up along the plasma membrane, forming pairs in juxtaposition.

Surface and internal temperatures of bags made by Thyridopteryx ephemeraeformis (Haworth) as well as ambient temperatures were recorded in sun and shade. Temperatures of bags in both shaded and exposed areas of the tree were significantly higher than ambient air temperatures. Bag surface temperatures were not significantly different from internal bag temperatures. Differences between internal, surface, and ambient temperatures could not be attributed to host tree species. Finally, there were no significant differences in temperature between bags with and without larvae.

Several chemosterilants have been tested against insects (Borkovec 1966). As a result, a total or partial sterility and decrease in fecundity have been noticed in several insects. Amongst Aphididae, Brevicoryne brassicae L., Myzus persicae Sulzer, Aphis fabae Scop., Macrosiphum euphorbiae Thomas, and Acyrthosiphon pisum (Harris) have been tested to determine the effects of chemosterilants like tepa, thiotepa, and metepa (Bonnemaison 1966; Bhalla and Robinson 1966, 1968; Chawla et al. 1973, 1974; Sharma et al. 1980; Steffan and Stüben 1976). In all previous work, either viviparae or their nymphal instars were the object of chemosterilant treatment and up to 95% reduction in fecundity was observed. Nothing to date has been described on the effect of chemosterilants on the sexuparae or sexuales of Aphididae. To continue with the results obtained by Sharma and Thériault (1980) and Sharma et al. (1980) on the viviparae, this paper describes the effects of 0.5% thiotepa [Tris (1-aziridinyl) phosphine sulphide] on sexuparae of the pea aphid, Acyrthosiphon pisum (Harris), and their progeny.

Populations of the bromegrass seed midge, Contarinia bromicola Marikovskiy and Agafonova, were sampled in bromegrass plots in Saskatchewan in the years 1974 to 1980 inclusive. Two peaks of midge adult numbers were observed, the first at bromegrass heading time in early June and the second about 20–25 days later at bromegrass flowering. Parasitism by a species of Tetrastichus (Eulophidae) varied from 30% to 75%. Carbofuran (0.14 kg A.I./ha) or dimethoate (0.56 kg A.I./ha) spray, applied just before emergence of adult midges at flowering time, significantly reduced numbers of midges and parasites resident in the plants in both of two field tests; a second generation of midge larvae, following invasion by midge adults, was significantly reduced by residual treatment effect in only 1 of the 2 years.

Pissodes strobi (Peck) and P. approximatus Hopkins are sibling species that can produce fertile hybrids in the laboratory, but in nature they are isolated by differences in their breeding habits. In a laboratory assay for feeding preference, these species exhibited similar patterns of acceptance of most conifer hosts in the fall, but differed distinctly in their preferences for certain conifers in the spring. Both species had high levels of feeding on white spruce in the fall and spring tests, hut these data apparently do not reflect host preference in nature. In field tests, P. strobi males and females confined on 1-year-old terminal leaders of eastern white pine (their usual breeding sites) produced abundant progeny, whereas P. approximatus pairs confined on leaders produced few progeny. Mixed species pairs were successful in killing and breeding in white pine leaders when the females were P. strobi, but not when the females were P. approximatus. Laboratory-reared hybrids were unsuccessful when forced to breed in leaders. When confined on red pine bolts (the usual breeding sites of P. approximatus), P. strobi and hybrids produced substantially fewer progeny than did P. approximatus. Breeding site separation provides compelling evidence of reproductive isolation between these sympatric species.

A sequential decision plan, based on the negative binomial distribution and providing for two infestation classes, has been derived for use in management of the alfalfa blotch leafminer, Agromyza frontella (Rond.), in southern Ontario. It utilizes counts of the eggs in leaflets of alfalfa, and in economic situations will provide growers with sufficient lead time to consider alternative action strategies. An appraisal of the plan by field scouts showed that it rated the infestation status of the leafminer correctly in 48 of 51 cases. Sampling time averaged 25 min per scout per field.

Some time ago I published data on orthopteroid insects from northern Canada and Alaska (Vickery 1967, 1969). Two species and one subspecies were described as new. Two of these taxa occur only in the Yukon and Northwest Territories.

Since that time additional information has become available. During 1982 two lots of northern orthopteroid insects were received for identification. These were sent from the Spencer Museum, University of British Columbia and from Biosystematics Research Institute, Canada Agriculture, Ottawa. These are abbreviated in the following list as UBC and CNC, respectively. The UBC specimens were collected by S. G. Cannings, R. J. Cannings, C. S. Guppy, B. Gill, and G. G. E. Scudder mainly in 1980 and 1981. The CNC specimens were collected in 1981 by C. D. Dondale.

Larvae, and male and female adults, of Acalyptonotus neoviolaceus n. sp., and male and female adults of A. pacificus n. sp., are described from western North America. A revised diagnosis of Acalyptonotus is proposed based upon larvae and adults, and the phylogenetic relationships and taxonomic status of Acalyptonotidae are discussed.

Two new species of Braconidae are described from North America. Illidops terrestris new species was reared from Elasmopalpus lignosellus (Zeller), and is the first described species of Illidops from North America. Bracon compressitarsis new species was reared from the boll weevils Anthonomus grandis Boheman and A. hunteri Burke and Cate. It is distinguished from other braconids previously recorded from boll weevils.