The Nearctic Idiocerini exclusive of the fauna of the Sonoran subregion are reviewed. The 68 recognized species are assigned to three genera: Idiocerus Lewis, Rhytidodus Fieber, and Balcanocerus Maldonado-Capriles. Three subgenera of Idiocerus are recognized, including I. (Liocratus) Dub. and I. (Populicerus) Dlab. (n. stat). Sahlbergotettix Zvk., 1953, Viridicerus Dlab., 1974, Tremulicerus Dlab., 1974, and Acericerus Dlab., 1974 are synonymized with Idiocerus Lewis, 1834.

Sixteen new species of Idiocerus are described: aureus, carolina, cedrus, freytagi, gillettei, immaculatus, inebrius, iodes, lucidae, midas, pericallis, taiga, unicolor, vanduzeei, venosus, and xanthiops. I. varions n. n. is created for varias DeLong & Hershberger, 1947 (nec Germar, 1818). I. lunaris Ball (n. stat.), I. obsoletus (Wlk.) (n. stat.), and I. raphus Freytag (n. stat.) are recognized as valid species for the first time. Twelve other species are removed from synonymy. I. verrucosus Ball is placed as a subspecies of I. musteus Ball (n. stat.). Five new synonymies are created: alnirubratus Bliven, 1955 = I. couleanus Ball & Pkr., 1946; nigrens DeL. & Cld., 1937 = I. distinctus Gill & Bak., 1895; duzeei Prov., 1890 and vagus Ball, 1902 = obsoletus Walker, 1851; and apertus DeL & Hbr., 1947 = I. verticis (Say), 1831.

Additional characters of the male antennae, male abdominal apodemes, and female ovipositor are described and illustrated. The phylogeny and hosts of the members of Idiocerus are discussed. Keys are provided to the genera of the Nearctic Idiocerini, and to the species of Idiocerus of the Nearctic region, exclusive of the Sonoran subregion, for both sexes.

Daily periods of activity of eight colonies of the eastern tent caterpillar, Malacosoma americanum (F.), were monitored photoelectronically under a simulated springtime photoperiod in the laboratory. Colonies averaged 3.7 ± 0.1 (S.E.) activity periods per day (N = 103 colony-days), separated by an average interval of 6.6 ± 0.1 h (N = 389). Foraging trips lasted an average 2.8 ± 0.1 h (N = 397). A plot of 336 activity period midpoints (seven colonies) showed all colony activity peaks to occur between 0600 and 0800 h, 1100 and 1600 h, 1900 and 2100 h, and 0100 and 0400 h. The first three peaks correspond well to previously reported field observations but the early morning foraging trip, which occurred in darkness, was previously unreported by field investigators. The temporal placement of activity peaks shifted from day to day within colonies but the occurrence of evening foraging trips was the most consistent. Dark onset appeared to trigger foraging in resting colonies. Recruitment of hungry caterpillars to food finds appears to be a common component of the foraging strategy of this species.

Lophyroplectus luteator (Thunb.), a European ichneumonid parasite previously established on Neodiprion sertifer (Geoff.) in southwestern Ontario, was released near Hepworth, Ontario in 1970, on Manitoulin Island and in Sault Ste. Marie, Ontario in 1972. All three releases resulted in establishment. Data on attack levels and host densities are presented for up to 4 years after release. Dispersal within release areas was rapid. In the first generation after release on Manitoulin Island parasites were obtained up to 900 m from the release site.

Probit analysis of the dosage response of codling moth stages to methyl bromide indicated that adults were most, and pupae, least susceptible. Eggs were more resistant than cocooned larvae which were more resistant than larvae in fruit. There were no differences in susceptibility of the larval instars to methyl bromide. The rate recommended to kill larvae in fruit (32 g/m3 for 2 h) also killed eggs.

Synthetic sex attractants were used to trap Rhyacionia pine tip moths throughout the western United States in spring and early summer 1977 and 1978. Some species were shown to have much wider distributions than previously known. Among species responding to (E)-9-dodecenyl acetate, R. zozana was collected over most of the area, with new records for Washington, Idaho, Montana, Wyoming, and South Dakota; R. neomexicana was found for the first time in Utah, as was R. salmonicolor in New Mexico, Colorado, and Utah; R. monophylliana in Nevada and Utah; R. jenningsi in New Mexico; and R. multilineata in Arizona and Oregon. Among species caught in traps baited with (E,E)-8,10 dodecadienyl acetate, R. busckana was found widely through the Northwest, for the first time in Montana and Wyoming, and R. fumosana was captured throughout the Rocky Mountain states, with new records for Montana, Utah, and Nevada. Sets of two previously unknown zozana -like moths were collected. One is closely associated with the typical form in Oregon and California; the other is a pinyon associate in Colorado and New Mexico.

A laboratory bioassay technique using adult Drosophila melanogaster was developed to measure the vapour toxicity and sorption by soil of seven insecticides. The laboratory results were then compared with those from field trials measuring the effectiveness of the same insecticides in protecting potatoes from wireworm attack. There was sufficient agreement between the laboratory and field tests to indicate that the laboratory bioassay may be useful for screening insecticides preliminary to field wireworm control studies. Of the newer ’insecticides tested, fonofos, terbufos, and chlorpyrifos in descending order of efficacy, gave substantial protection from wireworm damage.

Four new species are described: Mimesa foxi, M. huron, M. iroquois, and M. mallochi. Diagnostic characters are listed for each species and each species is compared with other closely related species in the genus.

Either (E)- or (Z)-11-tetradecenal, the two pheromone components, or one analogue, 9-(cyclopent-2-en-1-yl)-nonanal, effectively reduced mating of spruce budworm moths, Choristoneura fumiferana (Clem.), in the laboratory. The results suggest that different behavioural and physiological processes may be occurring in pheromonal attraction and close range mating prevention in the spruce budworm.

Two synthetic pheromones, frontalin and seudenol, were tested on living host (Picea) trees and on non-host (Abies) trees to determine their relative attractiveness to the spruce beetle (Dendroctonus rufipennis) and a clerid predator (Thanasimus undatulus). On host trees, frontalin attracted significantly more spruce beetles and induced significantly more attacks on the trees than did seudenol. On non-host trees, more beetles and a higher male ratio were attracted to seudenol than to frontalin. Frontalin has a positive effect on the behavior of female spruce-beetle attack, whereas seudenol has not. The resulting natural secondary attraction of attacking female beetles creates strong aggregation of both sexes of spruce beetles on host trees (Picea) baited with frontalin, but not on host trees baited with seudenol or on non-host trees (Abies). The clerid predator (T. undatulus) was attracted to frontalin in significatnly larger numbers than to seudenol.

Preconditioning of isolates of Beauveria bassiana (Bals.) Vuill. and Metarrhizium anisopliae (Metch.) Sor. with specific insects increases their virulence. An isolate of B. bassiana used two years previously in pathogenicity tests against spruce budworm, Choristoneura fumiferana Clem., required only one passage through this insect to attain 100% mortality in 48 h of incubation, whereas an isolate of M. anisopliae that was not previously used against this insect required four passages to attain the same degree of virulence as B. bassiana. Larvae of Laspeyresia youngana (Kft.), Dasineura rachiphaga Tripp, and Dasineura canadensis Felt were very susceptible to both fungi and 100% mortality was obtained in less than 48 h of incubation. Larvae of Lasiomma anthracina Czerny were much less susceptible. Puparia of both genera of Diptera were more resistant than larvae and required longer incubation to obtain 100% mortality.

Adult and nymphal populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), on “Contender” green beans, Phaseolus vulgaris L., were sampled during the summers of 1971–1972. Sweep net and D-Vac® suction apparatus samples were taken concurrently, and both estimates were compared by regression analysis.

The tarnished plant bug reached levels above the economic injury levels for both early and late crops in 1971–1972. The economic threshold was determined as 0.5 insect/10 plants below the economic injury level.

The phenologies and distributions of pea aphid (Acyrthosiphon pisum (Harris)), blue alfalfa aphid (A. kondoi (Shinji)), and spotted alfalfa aphid (Therioaphis maculata (Buckton)) were intensively studied in California alfalfa. The results showed, as expected, that aphid populations across all densities were aggregated; but that ladybird beetle (Hippodamia convergens (G.-M.)) predation increased the degree of aggregation. The distribution parameters of the aphids were estimated using methods developed by Iwao and Kuno (1971).

Granular treatments of thiofanox (Dacamox 10 G®) and carbofuran (Furadan 10 G®) and spray treatments of dimethoate (Cygon 4E®) and pirimicarb (Pirimor 50 WP®), all gave good control of cereal aphids and increased barley grain yield significantly above controls.

The granular treatments did not significantly reduce parasites and predators of the aphids. Predators and parasites showed a reduced population 1 week after foliar insecticide applications. However, pirimicarb showed a relatively reduced effect compared with other pesticides on the available predatory species, 2 weeks after spraying.

The subgenus Chrysonotomyia Ashmead s. str. is reviewed. Eight species are recognized and three new species are described: C. baliosa n. sp., C. solidaginis n. sp., and C. cunicularia n. sp. Keys to species, list of hosts, list of misidentified species, and distribution records are included.

The preservation of host material in a state suitable for successful development of beneficial parasite or predator species is desirable for the mass culture of entomophagous species. Thus, Coppel and Mertins (1977) report the coddling of sawfly cocoons, and Fedde et al. (1979) chilled host eggs to keep them in a susceptible state for the egg parasite Telenomus alsophilae Viereck. Such techniques are also valuable to assure continuous rearing of parasites or predators during shortages of hosts.

The latter situation pertained while we were studying factitious hosts of the thelyotokous, multivoltine egg parasite Ooencyrtus ennomophagus Yoshimoto (1975). This parasite cannot develop in embryonated eggs; therefore it is essential to hold hosts in the unembryonated condition. Faced with the loss of the typical host for 0. ennomophagus, the univoltine elm spanworm, Ennomos subsignarius (Hübner), we found that eggs of the multivoltine pipla tentmaker, Clostera inclusa (Hübner), would suffice. Field populations of the tentmaker crashed in 1979, leaving us dependent upon a small field-cage rearing of this insect for experimentation.

The sex pheromones of Archips argyrospilus (Walker), Archips rosanus (L.), Choristoneura rosaceana Harris, and Pandemis limitata Rob. were evaluated in orchards with the objective of developing a method of monitoring leafroller population densities. The sex pheromones were specific for three species but not for C. rosaceana. This leafroller was captured in traps containing A. rosanus sex pheromone more frequently than in traps with its own attractant. The trapping program indicated that C. rosaceana and P. limitata were abundant in the southern fruit growing region of British Columbia and that A. argyrospilus and A. rosanus were the predominant species in the northern region. The traps can be used to identify leafroller species in orchards and to indicate when moths are active which may help in timing control measures.

Pre-attack feeding for 48 h on a diet containing 200 ppm Dimilin® (diflubenzuron), by adult Dendroctonus rufipennis (Kirby) (Coleoptera: Scolytidae), caused a complete inhibition of larval eclosion from eggs deposited by such beetles in the untreated host logs for the duration of the reproductive cycle. Inhibition of larval eclosion was mediated through the females only. Pre-attack application of 1% Dimilin to host logs reduced the number of larvae per gallery by 55% and reduced the number of galleries with successful larval eclosion by 42%.

A series of sod-lined pools were constructed and used to monitor repeated applications of diflubenzuron as Dimilin WP-25 and mefhoprene as Altosid SR-10. Diflubenzuron and methoprene "disappeared" rapidly from the pool water as determined by bioassays using Aedes aegypti (L.) (Culicidae) larvae and by gas-liquid chromatography (GLC). Chemical assays for a diflubenzuron derivative were positive for several days; bioassay indicated the presence of diflubenzuron (or at least growth regulator activity) at levels toxic to mosquito larvae for up to 16 days. In contrast methoprene "fell" below GLC detection within 2 days although biological activity persisted for approximately a week after treatment. Neither parent compound should cause a long-term persistence hazard when used for mosquito control in Canadian prairie waters.

Caged microplots of “Contender” green beans, Phaseolus vulgaris L., were artificially infested with various densities of Lygus lineolaris (Palisot de Beauvois) to determine the effect of feeding on yield and quality, and to establish economic injury levels. Plants infested at bloom or pod set stage were more severely injured than those infested at the flower bud stage. Higher infestation levels reduced crop yield, but the percentage of crude protein in bean seeds was not affected. Based on 1975 crop values and chemical control costs, economic injury levels ranged between 0.3 and 4.4 insects/10 plants depending on crop use, chemical control, and plant stage infested.

Intruding Oecanthus nigricornis (Walker) females stole nutritional glandular secretions from males engaged in post-copulatory behavior with their mates. This mating strategy may enhance female reproduction.

Mating behavior of Oecanthus spp. begins with elaborate male courtship involving vibratory, acoustic, and olfactory signalling. The female mounts the male, with copulation occurring soon after. During courtship and after copulation the female remains mounted and is provided with male metanotal glandular secretions. These nutritional secretions and the consumed spermatophore increase reproduction (Bell 1979; in press).