The seasonal damage to female reproductive structures (buds, flowers, and cones) of black spruce, Picea mariana (Mill.) B.S.P., was assessed during 1983 and 1984. Nineteen insects (five Orders) and the red squirrel, Tamiasciurus hudsonicus (Erxleben), were found feeding on these reproductive structures. Collectively, these organisms damaged 88.9 and 53.5% of the cones in 1983 and 1984, respectively. In the 2 years, Lepidoptera damaged 61.8% of the cones in 1983 and 44.4% of the cones in 1984. The spruce budworm, Choristoneura fumiferana (Clem.), and the spruce coneworm, Dioryctria reniculelloides Mut. and Mun., were the most important pests. Cones damaged by Lepidoptera could be classed into three categories: (a) severe, yielding no seeds; (b) moderate, yielding 22.3 seeds per cone; and (c) light, yielding 37.5 seeds per cone. Undamaged cones yielded on average 39.9 seeds per cone. Red squirrels removed 18.8% of the cones in 1983 and none in 1984. The spruce cone axis midge, Dasineura rachiphaga Tripp, and the spruce cone maggot, Lasiomma anthracinum (Czerny), caused minor damage in both years. Feeding by spruce cone axis midge did not reduce cone growth significantly or the number of viable seeds per cone, but feeding by the spruce cone maggot did. During both years new damage by insects to the female reproductive structures of the experimental trees was not observed after mid-July. In 1983 damage by red squirrels occurred from early to late September. In 1984 damage to cones on trees treated with dimethoate was 15.6% compared with 53.5% for untreated trees, without an increase in the number of aborted cones.

Of nine treehopper species presented to the lizard, Anolis carolinensis, two were unpalatable. The basis for rejection of newly emerged adults of Umbonia crassicornis and Platycotis viltata appeared to be taste. As these adult insects matured the pronotum became highly sclerotized. Mature P. vittata lost their aposematic color and became palatable while U. crassicornis continued to be rejected. Both species brood their young and form large conspicuous aggregations.

Anaphes iole Girault is redescribed from specimens reared from Lygus hesperus Knight and Pseudatomoscelis seriatus (Reuter). Anaphes anomocerus, A. ovijentatus, and A. perdubius are synonyms of A. iole. Host-induced morphological variation is discussed. The main attributes that vary with host are the relative size of certain funicular articles and their complement of sensory ridges. There is no morphological overlap between populations as indicated by measurements of most other structures. However, certain structural features that can be used to define the species unequivocally were found.

The following new taxa of Quediini (Staphylinidae) are described: Heterothops giulianii spec, nov. (California), and Acylophorus (Acylophorus) zdenae spec. nov. (Illinois, Louisiana, Texas). A revised key to North American species of Heterothops Steph. is presented as well as revised couplets for the keys to the genera of Quediini and species of Acylophorus. A lectotype is designated for Quedius compransor Fall.

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

Three species of Hymenoptera comprise the guild of parasitoids utilizing alfalfa weevil, Hypera postica, larvae in Ohio. Where all three coexist, there has been a yearly increase in parasitization by Bathyplectes anurus and concomitant decreases in Bathyplectes curculionis and Tetrastichus incertus. We conclude that B. anurus dominance is due to its precise synchronization with peak host numbers, its high reproductive capacity, competitive superiority, and rapid search and handling. Domination of ephemeral hosts by such a parasitoid is in agreement with the general conclusions of Force, and Ehler and van den Bosch. B. curculionis and T. incertus compensate for imperfect synchrony with multivoltism and vagility (both spp.), aggregation and rapid search (B. curculionis), or random search and gregarious development (T. incertus).

Stress caused by two biocontrol agents on their weed host Canada thistle [Cirsium arvense (L.) Scop., Asteraceae] was investigated. The combined attack of the gall-fly Urophora cardui (L.) (Diptera: Tephritidae) and the stem-mining weevil Ceutorhynchus litura (F.) (Coleoptera: Curculionidae) caused a significant reduction in the vigour of the attacked plants as measured by the number of live buds in the 1st year and by the dry weight of the roots in the 3rd year. The attacks did not significantly reduce the number of aborted buds, mature seed heads, and new shoots, nor the combined dry weight of the leaves, stems, and galls as compared with Canada thistle plants that had not been galled or mined, in any of the 3 years. Non-structural carbohydrate content of the roots of attacked shoots was found significantly reduced only at the end of the mining period.

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 systematic revision of North American species of the genus Ameletus, excluding parthenogenetic species, is presented. Seven new species are described (A. andersoni, A. bellulus, A. doddsianus, A. edmundsi, A. majusculus, A. pritchardi, and A. tolae), separate keys are given to western and eastern species, annotated accounts of all 30 presently recognized bisexual species are provided, taxonomic characters are illustrated, and distribution data are presented for all species. The following nomenclatural changes are proposed: Ameletus aequivocus is considered a junior synonym of A. sparsatus; A. alticolus and A. celeroides junior synonyms of A. celer; A. connectina and A. connectus junior synonyms of A. velox; A. facilis a junior synonym of A. vancouverensis; A. monta a junior synonym of A. similior; A. querulus a junior synonym of A. shepherdi. The specific status of A. tuberculatus is questioned and it is provisionally considered to be the same as A. celer.

The existence of strains of mites resistant to parathion has been well established (Garman, 1950; Lienk, Dean, & Chapman, 1952; Newcomer & Dean, 1952; Smith & Fulton, 1951). Resistant strains of the European red mite, Metatetranychus ulmi (Koch), first occurred in orchards of the Pacific northwest in 1950 (Newcomer, 1951; O'Neill & Hantsbarger, 1951), approximately three years after parathion was first used as an acaricide. Two other species of orchard mites, the Pacific mite, Tetranychus pacificus McG., and T. mcdanieli McG., were subsequently reported to have developed parathion-resistant strains in the same area (Newcomer & Dean, 1953). Though parathion is lethal to most predacious mites and insects, Huffaker and Kennett (1953) found a difference in tolerance between species of Typhlodromus in the field and in the laboratory: T. reticulatus Oudms. was very susceptible to parathion whereas T. occidentalis Nesbitt was not appreciably affected by it.

Methods and materials for colonizing damselflies (Ischnura) in the laboratory are described. Adults cease escape behavior in vision-proof cages. Females copulate only after first rejecting several would-be mates in succession and do not begin to oviposit until two to four hours afterwards. Artificial Du Pont sponges provide the best material for egg deposition. Methods of rearing large larval numbers are briefly described.

A visible mutation with salmon-colored eyes was found in our colony of Glossina morsitans morsitans Westwood. The trait, designated salmon (sal), is a recessive controlled by an X-chromosome locus which is at least 36 map units from ocra. Adults emerged from less than 20% of the puparia obtained by mating females homozygous for salmon with the hemizygous salmon males; these flies have very pale eyes and die at an early age. The mutant is genetically rescuable since females homozygous for salmon mated with wild-type males produced the normal number of phenotypically wild-type female offspring and about 32% of the expected number of male offspring; the males have very pale eyes.

Sex pheromone traps to control codling moth by male removal was evaluated in three orchards in the Okanagan Valley. The program was successful in only one of the three orchards. This orchard is completely isolated and codling moth control has been obtained for 5 years. In a second orchard, codling moth populations were reduced by sprays prior to the male removal program. The program was successful in 1977, as the per cent injured fruit was only 0.6. In 1978, the codling moth capture rose sharply and at harvest the per cent injured fruit was 8.0. There was a high infestation in the third orchard when the program was initiated, and in 1976, the per cent injured fruit dropped to 10.4% from 60.0 in 1975. The per cent fruit injured by codling moth rose to 37.4 in 1977 and to 60.2 in 1978 under the male removal program. Our data show that this method of control is effective only under special circumstances, where codling moth populations are low and where isolation precludes reinfestation.

Two species of opiine (Braconidae) parasitoids, Opius lectoides Gahan and O. downesi Gahan parasitized Rhagoletis zephyria Snow and R. pomonella (Walsh) in the Willamette Valley, OR. Almost equal numbers of O. lectoides and O. downesi were recorded from R. zephyria, whereas about 91% of the opiines associated with R. pomonella were O. downesi. In general, percent parasitization of R. pomonella was variable from sample to sample, but substantially higher on hawthorn than on apple fruit. It appears that both the opiine species have made a rapid host shift from R. zephyria to newly introduced populations of R. pomonella.

A systematic analysis of larvae of 11 Nearctic species of Hygrotus Stephens was undertaken. The larvae are described and characterized; a key for their discrimination and illustrations of structural features of representatives of first- and third-instar larvae are provided. Many structural features, especially detailed variations in the chaetotaxy of cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi, were found to be useful for systematic and phylogenetic comparisons. Based on 21 larval characters, a cladistic analysis of the species studied was developed. A sister-group relationship between H. laccophilinus (LeConte) and the remaining available species is suggested. The less derived species, i.e. those without natatory setae on the legs, appear phylogenetically more closely related to the larvae of Hydroporus s.str. Hygrotus masculinus (Crotch) is the most derived species of the genus and, for many characters, seems more closely related to Hyphydrini. According to larval morphology, it is hypothesized that the genus Hygrotus diverged posteriorly to the genus Hydroporus Clairville.

The damsel bug, Nobis americoferus Carayon, develops through two generations a year in eastern Ontario. In early fall, females of the second generation develop a reproductive diapause but both sexes continue to feed until freeze-up. Post-diapause development begins in late March. Eggs are deposited singly in plant stems but several may be laid in close proximity. In alfalfa, most eggs were found where stem diameter measured from 0.8 to 1.9 mm but height of oviposition site was not related to length of stem. Females reared at 23°C laid an average of 157 eggs during a 3-week oviposition period. The immature stages of the first generation occurred from mid-April to mid-July and those of the second generation from mid-July to early September. The duration of each stage of N. americoferus, fed pea aphids, Acyrthosiphon pisum (Harr.), and held at four constant temperatures, 18, 23, 28, and 31°C, decreased with increasing temperature. There was a highly correlated linear relationship between rate of development and temperature for all stages. The theoretical temperature threshold for development of eggs was 11.1°C and that for the nymphal stage was 10.6°C; degree-day requirements for these stages were 123.5 and 370.4, respectively. Developmental rate of nymphs varied with host as well as temperature; nymphs fed larvae of the alfalfa blotch leafminer, Agromyza frontella (Rondani), developed significantly faster than those fed pea aphid.

Degree-day relationships in the development of Lithocolletis blancardella (Fab.) and Apanteles ornigis Weed, its major parasite, were established from laboratory and field studies in Ontario apple orchards during 1973, 1974, and 1975. Under constant laboratory conditions, temperature thresholds for development of overwintering pupae were estimated by three methods, and found to be 6.3°, 6.7°, and 5.7°C for L. blancardella, and 10.4°, 10.4°, and 11.3°C for A. ornigis. Degree-day accumulations in the field were calculated by two methods using daily maximum and minimum temperatures recorded from the pupal habitat and a Stevenson screen. Degree-days in the pupal habitat accumulated from 1 January, above 5.7°C for L. blancardella and 11.3°C for A. ornigis were more accurate than Stevenson screen degree-day accumulations for predicting first emergence; however, after emergence, seasonal development was best related to Stevenson screen degree-days accumulated from 1 April, above 6.7°C for L. blancardella and 10.4°C for A. ornigis. This study shows that degree-day relationships can be used in an apple pest management programme to optimize timing of insecticide applications against L. blancardella and preserve A. ornigis, its major natural enemy.

The extant types of chalcids described by Provancher are re-examined. A few are lost or so badly damaged that accurate placement is now impossible, but the majority of species are correctly identified in modern literature. Five new combinations and nine new synonymies are proposed.

The occurrence, quantification, and distribution patterns of deformed wing virus (DWV) and sacbrood virus (SBV), (family Iflaviridae); black queen cell virus (BQCV), Israeli acute paralysis virus (IAPV), Kashmir bee virus (KBV), and acute bee paralysis virus (ABPV) (family Dicistroviridae), and chronic bee paralysis virus (CBPV) (unclassified), were characterised in 80 “healthy” honey bee (Apis mellifera Linnaeus; Hymenoptera: Apidae) colonies and 23 “unhealthy” colonies by employing reverse transcription polymerase chain reaction (RT-PCR) for virus identification and quantitative real-time polymerase chain reaction (qPCR) for quantification. All seven viruses were common but the most prevalent viruses were DWV, followed by BQCV and IAPV. For most viruses, prevalence in surviving but unhealthy colonies in spring did not differ from that of healthy baseline colony levels in fall suggesting spring prevalence level would not be a useful metric for diagnosis of factors contributing to colony loss. Sacbrood virus was the only virus that was more prevalent in unhealthy colonies from Manitoba, Canada than in healthy from colonies across Canada but did not differ from healthy colonies within Manitoba. Multiple infections were ubiquitous with a few colonies having simultaneous infection with as many as five viruses. Among the three viruses quantified by qPCR, DWV had the highest relative concentrations in pooled samples of worker bees. Deformed wing virus was the only virus within healthy colonies that differed in fall concentration among provinces and was at high levels in unhealthy colonies. Black queen cell virus was positively correlated with IAPV across all samples. Our study provides the first major baseline study of viruses in Canadian honey bees.

Several criteria for determining the sex of the southern pine beetle, Dendroctonus frontalis Zimm., were investigated. The combination of the prominence of the frontal tubercles and depth of frontal groove was 100% accurate and was chosen as the best criterion. Data on sex ratios at different points in the beetle's life history are given.

All, postembryonic instars of Hoploseius tenuis n. sp. are described and illustrated. This species is numerous in the pores of coniferous bracket fungi where it presumably feeds on the fungus. Discussed are: the relationship of this species to congeners, and the modification of the generic concept; the ontogeny of the body and leg setation, which includes larval, pustlarval and regressive deficiencies, and retardation; and the ontogeny of body elongation and its effect on the positions of setae. The adult morphology and setation of H. tenuis is briefly compared with that of an elongate digamasellid, Longoseius cuniculus Chant.