Smith (Day and Smith 1980) identified mature dipteran eggs attached to the thorax of adult females of European Rhopalum clavipes (L.) (Hymenoptera: Sphecidae) as Ptychoneura minuta (Fallén) (Sarcophagidae: Miltogramminae). R. clavipes is widespread in North America (introduced) but examination of previously collected specimens, a literature search, and discussions with specialists (H. K. Townes, American Entomological Institute, Ann Arbor, Michigan and G. E. Shewell, Biosystematics Research Institute, Ottawa, Canada) indicated that this behaviour had not previously been recorded in North America.

Three house fly, Musca domestica L., strains, two from farms near Guelph, Ontario and one from a farm near Edmonton, Alberta were cultured and tested for their resistance to insecticides as compared with a susceptible laboratory strain. The two Guelph strains were resistant to the 7 organochlorine (OC) and 11 organophosphorus (OP) insecticides tested and to nearly all of the carbamate insecticides. One Guelph strain (A) which had been subjected to minimum pyrethrins pressure and no residual pyrethroid pressure was susceptible to pyrethrins and the 8 pyrethroid insecticides tested. The other Guelph strain (B), which had been subjected to intense pyrethrins–pyrethroid pressure, was resistant to pyrethrins and to all pyrethroids tested. The Edmonton strain had a history of insecticide exposure similar to the Guelph B strain and showed a similar resistance pattern. Resistance levels at the LD50 for the Guelph B strain, as compared with a susceptible laboratory strain, for the OP insecticides tested, ranged from ×50 for malathion to ×4.5 for dichlorvos; for the carbamates, from ×13.5 for bendiocarb to ×4.1 for methomyl; and for the pyrethroids, from ×55.6 for deltamethrin to ×18.7 for fenvalerate.

A generic description of the larvae of Pagastia Oliver is presented. The larvae of three Nearctic species, P. partica (Roback), P. sequax (Garrett), and P. sp. A are described. A diagnostic key to these species is included.

Larvae of Cucujus clavipes (Fabricius) and Dendroides canadensis (Latreille) are frequently found under bark of decaying hardwood logs and those of Pytho depressus (Linnaeus) under that of dead conifers, especially pine (Pinus spp.) (Anderson and Nilssen 1978). Larvae of all three species have a dorsoventrally depressed, orthosomatic body and are well adapted for activity in the cambial layer. In dead trees, this area contains partially decomposed wood and bark resulting from the activity of phytophagous insects and other small invertebrates. According to textbooks of general entomology and other entomological literature, species within the genera Cucujus, Dendroides, and Pytho are predacious on other insects found in the cambial layer (Arnett 1968; Borrer et al. 1976; Borror and White 1970; Essig 1926; Peterson 1951; Swan and Papp 1972). However, no specific references to original studies demonstrating this type of feeding behaviour could be found. The purpose of this study was to determine the type of food consumed by larvae of these species and to determine if the structure of their mandibles and other mouthparts were indicative of such food consumption.

An understanding of all environmental effects resulting from control actions is important in the selection of a method of managing insect populations. Effects may extend beyond the year of treatment and can modify management decisions. In 1978, a nuclear polyhedrosis virus (NPV) and Bacillus thuringiensis Berliner (B.t.) were tested as aerial spray applications against the western spruce budworm, Choristoneura occidentalis Freeman, on Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, near Cache Creek, British Columbia. The impact on population densities and on the incidence of NPV was measured in the treated and non-treated areas for 2 vears following the year of application, and is reported here.

Female Culex tarsalis Coquillett trapped in CO2-baited light traps or reared from field-collected pupae were marked with fluorescent dust, released, and recaptured in traps baited with CO2 with or without light. Recaptures of trapped females peaked on the first night of recapture collections. Recaptures of reared females peaked on the first or second night when autogeny rates were low (25–44%) but 2-4 nights later when rates were high (86–88%). It was concluded that autogenous females did not seek blood until after they had oviposited, and that autogenously induced delays in feeding probably influence the extent of virus transmission by C. tarsalis.

Stretched follicular tubes indicating recent oviposition were found in 23.4% and 5.2% of empty parous females from shelters and CO2-baited traps, respectively, and in 2.3% of freshly engorged parous females from shelters. Females often failed to blood-feed until at least the second night after oviposition.

Eclosion of overwintering eggs of the European red mite, Panonychus ulmi (Koch), in Nova Scotia was studied at four constant temperatures. Days to 50% hatch were 44.8, 23.1, 12.9, and 8.8 while the rates of development were 2.18, 4.53, 7.59, and 11.34% per day at 8°, 12°, 16 °and 20 °C, respectively. Nonlinear equations were developed to estimate the time to 50% hatch of overwintering eggs as a function of temperature. A weighted average of the daily extreme temperatures was used to improve the estimated time to 50% hatch for field data from the rates of development in the constant temperature studies.

Insect mines have been reported in several fossil leaf specimens (Brooks 1955; Freeman 1965; Lewis 1969; Opler 1973; Hickey and Hodges 1975; Crane and Jarzembowski 1980). These fossils represent useful records for the study of insect-host evolutionary history. Opler (1973) and Hickey and Hodges (1975) compared fossil Ieaf mines with those caused by extant insect species in homologous host species and concluded that specific insect-host associations have persisted for as long as 50 million years. We report here the presence of leaf mines in a Miocene specimen of Mahonia reticulata (MacGinitie) Brown (Berberidaceae). It is unclear whether a comparable insect species is associated with extant Nearctic Mahonia Nuttall.

In western Quebec, first flight of overwintered adults of the northern June beetle, Phyllophaga fusca (Froelich), and the common June beetle, P. anxia (Le Conte), occurred in mid-May with the accumulation of about 156 degree-days above 5 °C beginning 1 April. When soil temperature was 10 °C or higher, flight started 12–45 min after sunset, apparently in response to an endogenous rhythm that was triggered by low light intensity within the range 1.0 to 96.9 lux; high soil temperature induced early flight. Early in the flight season, duration of flight was 10–46 min and was inversely related to time of flight initiation. In early June, the flight began in darkness and was associated with peak oviposition and ageing; it lasted 20–35 min and was directed into the trees or to oviposition sites within a field.

Males were attracted to light during a pre-copulatory flight which lasted more than 1 h until maximum coupling occurred near 2230 h; beetles remained in copula for 3 h or more. Morning flight directly back to the soil was triggered by light intensity increasing to about 1.0 lux.

Bioassays of Bacillus thuringiensis (Bt.) are commonly performed by applying a serial dilution of the test sample to either foliage or artificial diet (Burges and Thompson 1971). In these assays the ingested dose is not measured directly, but is assumed to be proportional to the concentration of the sample applied to the diet. This assumption is valid only if the total amount of food ingested during the experiment is the same at all dosage levels. However, this assumption may not be true because Bt. inhibits feeding of some lepidoptera larvae (Burges and Thompson 1971). Furthermore, artificial diets usually contain nutrients and possibly antimicrobial agents which may interact with Bt.

Dioryctria resinosella, a species feeding on red pine cones or shoots, is described as new and recorded from Maine, southern Ontario, Wisconsin, and Minnesota. The new species is distinguished from D. zimmermani (Grote) and D. banksiella Mutuura & Munroe by the differences in wing markings, genitalia characters, and ecological aspects.

Codling moth, Cydia pomonella (L.), control by sterile insect release (SIR) was assessed in 320–526 ha of apples and pears in the Similkameen Valley, B.C., from 1976 to 1978. In preparation for SIR, the moth population was first reduced to low numbers by removal of neglected trees in 1972 and by chemical sprays in 1975. Sterile (35 krad) male and female moths were released in each orchard 2 or 3 times weekly from 1 May until early September. A total of 23,600 sterile moths/ha was released in 1976, 36,500 in 1977, and 31,800 in 1978. Populations of sterile (marked) and wild moths were monitored by sex pheromone traps, and damage was assessed by fruit examination at harvest. Control was very good except for a few orchards in which overwintered populations were too high to achieve adequate overflooding with sterile moths. Damage exceeded the economic threshold (0.5%) in only 1 of 86 treated orchards in 1976, in 6 of 193 orchards in 1977, and in 0 of 157 orchards in 1978. Results in 32 orchards showed that when wild populations are brought close to extinction all codling moth control measures can be omitted for 2 or more years depending on degree of orchard isolation. Omission of codling moth sprays from 1976 to 1978 did not result in any important change in population levels of other apple pests. Cost of control by SIR was ca. $225/ha per year vs. ca. $95 for chemical control.

Tethered gypsy moth larvae, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), placed in various tree microhabitats were most heavily parasitized by Compsilura concinnata (Meigen) (Diptera: Tachinidae) near the ground especially on leaves. In laboratory experiments, hosts were parasitized primarily between 6:00 AM and 6:00 PM (E.S.T.), with little parasitism at night. These data suggest that in the field, this tachinid will most efficiently attack young gypsy moth caterpillars, as instars 1 to 3 are the only ones consistently on or near foliage during daylight. C. concinnata females successfully parasitized young hosts, but larval development on 2nd instars was twice as long as that on 4th instars. Thus, only one generation of parasitoids on gypsy moths is likely per year. Results indicate that methods for improving the effectiveness of this parasitoid should emphasize increasing adult numbers early in the season.

Three new oribatid mites, Niphocepheus aborigensis n. sp. (Niphocepheidae), Proteremaeus macleani n. sp. (Eremaeidae), and Asperemaeus longipilus n. gen., n. sp. (Eremaeidae), are described from subalpine habitats in the subarctic of the Soviet Far East.

Eggs of Sepedon fuscipennis (Diptera: Sciomyzidae) < 1, 1–2, 2–3, and 3–4 days old were offered to inexperienced female Trichogramma sp. near californicum in a laboratory experiment. Exposure period (2 h) and number of host eggs offered at one time (10) were held constant. Percentage of hosts parasitized, total number of parasitoid progeny found in a group of hosts, percentage of parasitized hosts yielding adult parasitoids, and survivorship of parasitoid progeny to adulthood all decreased significantly with increased host age. Younger hosts yielded more than one adult parasitoid more often than did older hosts. Over 50% of the adult parasitoids emerging from hosts < 1, or 1–2 days old were female. Hosts 2–3 days old produced only males. The data show a somewhat different relationship of host age to host acceptance and suitability than do some published data on lepidopteran hosts of Trichogramma.

Hybomitra enigmatica n. sp., previously confused with Hybomitra sonomensis (O.S.), is described in larval, pupal, and adult stages and compared with the latter species and with H. phaenops (O.S.). Hybomitra philipi Stone is synonymized with H. sonomensis. The distribution of these species in western North America is given.

UC-62644, a moult-inhibiting insect growth regulator (IGR) belonging to the benzoylphenylureas, had an EC50 of 0.1 to 0.2 ppm in a meridic diet for the 3rd to 6th larval instars of the spruce budworm, Choristoneura fumiferana Clemens. The effects of the IGR were apparent in less than 48 h after ingestion and there was evidence for some contact toxicity. The larvae were unable to discriminate between IGR-treated and untreated diet. Experimental aerial application of the IGR revealed that at <70 g in 4.7 1/ha (1 oz in 0.5 U.S. gal/acre) it effectively controlled spruce budworm populations and afforded foliage protection. These results were comparable with those obtained with Matacil® applied at the recommended rate.

The aphid parasite Praon callaphis, new species, from Afghanistan is described and illustrated. The species was introduced into California for the biological control of Callaphis juglandis (Goeze) on Juglans regia L.

The large aspen tortrix, Choristoneura conflictana Wlk., occurs throughout the range of trembling aspen, Populus trernuloides Michx., in Canada and the eastern United States (Baker 1972). Outbreaks of the insect occur over large areas, but these outbreaks generally collapse in 2 to 3 years. The principal effect of this pest is to reduce growth of aspen, but it causes little tree mortality (Batzer 1972). Prentice (1955) reviewed the history of outbreaks of C. conflictana in Canada from 1912 to 1953 and the natural control factors of the insect. He reported an extensive parasite complement. Dead and apparently diseased insects were examined, but the only pathogen noted was infection of overwintering larvae by the fungus, Beauveria bassiana (Bals .) Vuill.

This note deals with three European species of Orthotylinae now known to occur in Canada. Pilophorus confusus was discovered in 1976 in Nova Scotia and is reported for the first time from the Nearctic region. Additional distribution records are given for Orthotylus nassatus and O. viridinervis previously reported from North America by Henry (1977) and Henry and Wheeler (1979), respectively. The three species were likely introduced accidentally into this country some time ago with nursery stock importations but remained undetected until recently. They are predatory and overwinter in the egg stage. The adults of the three species are illustrated.