Females of Microctonus vittatae Mues., Microctonus punctulatae Loan and Wylie, and Townesilitus psylliodis Loan oviposited and survived in only some of the species of crucifer-infesting flea beetles that they encounter on rapeseed. M. vittatae oviposited readily in Phyllotreta striolata (F.), less often in Phyllotreta cruciferae (Goeze) and Phyllotreta pusilla Horn, and rarely in Psylliodes punctulata Melsh.; the progeny matured in P. striolata, P. cruciferae, and P. pusilla. M. punctulatae oviposited readily in P. punctulata and P. pusilla, occasionally in P. striolata, but never in P. cruciferae; the progeny matured only in P. punctulata and P. pusilla. Females of T. psylliodis oviposited readily in P. punctulata, rarely in P. pusilla and P. striolata, but never in P. cruciferae; parasite progeny matured only in P. punctulata.

Cypermethrin and carbaryl, as both aqueous sprays and bran baits, were tested in the field as crop protection measures against third-instar grasshopper populations infesting bromegrass and alfalfa–bromegrass pastures. Application of 15 g cypermethrin/ha as a spray reduced the grasshopper populations by 97% within 120 h; 700 g carbaryl/ha as spray reduced the populations by 90% during the same period of time after application. Neither insecticide applied on bran bait sufficiently reduced populations to be useful as crop protection measures against grasshoppers.

Six pyrethroids, cyfluthrin, cypermethrin, deltamethrin, fenvalerate, flucythrinate and permethrin, and two organophosphorous insecticides, acephate and chlorpyrifos, were applied to the soil surface in the greenhouse and field to evaluate their effectiveness and residual toxicity against the darksided cutworm, Euxoa messoria (Harris), in Ontario.

Four years of tests indicated that the pyrethroid insecticides were consistently similar in effectiveness and residual toxicity at the rates applied. On air-dry soil surfaces in the greenhouse, the pyrethroids were significantly more toxic and persistent than was chlorpyrifos. On moderately moist soil surfaces in the field, chlorpyrifos was as toxic to the cutworm larvae as were the pyrethroid insecticides, but less persistent. None of the pyrethroids was affected by soil moisture to the same extent as was chlorpyrifos. Acephate-treated soil surfaces, regardless of indoor or outdoor conditions, were less toxic and the toxicity less persistent than with chlorpyrifos-treated soil. Although not statistically different, the high rates of pyrethroids were consistently more toxic and persistent to the cutworm larvae than the low rates of the same materials. All the pyrethroid insecticides have excellent potential as soil treatments for controlling cutworms on tobacco.

Eosentomon canadense, n. sp., and E. bernardi, n. sp., both from southwestern Quebec, Canada, and E. vermontense, n. sp., from Vermont, U.S.A., are described and figured. A bibliography of recent works on North American Protura is appended.

Oviposition site selection by Tenebrio molitor L. was studied in cylindrical cages 10 cm in diameter × 28 cm in height using females up to 16 days old. Oviposition site selection is not a haphazard process. The adults are surface dwellers and the females normally enter the foodstuff to oviposit. The distance travelled into the foodstuff was age-related; the females went gradually deeper until the 9th day after eclosion. Physical and chemical factors (i.e. type and quality of foodstuff) and biological factors (i.e. adult density and presence of T. molitor eggs and larvae) were assessed when oviposition sites were selected by this insect. The females attempted to avoid poor quality food when selecting oviposition sites and usually laid fewer eggs and died sooner when poor quality food was present. As adult density increased, the females went deeper to oviposit. The females also went deeper to oviposit when eggs and larvae were present, but the effects of eggs and larvae were small and there seemed to be threshold densities as far as both factors were concerned. The behavioural significance of the data is discussed.

Pine oil effectively reduced feeding by the white pine weevil, Pissodes strobi Peck, in a laboratory feeding bioassay utilizing agar discs containing dry, powdered bark of its host Sitka spruce, Picea sitchensis (Bong.) Carr. Possible utilization of pine oil under field conditions is discussed.

The order of feeding preference on plant parts of rape (Brassica napus L.) by sixth instar (L6) larvae of bertha armyworm, Mamestra configurata Walker, in laboratory tests was leaves, bracts, immature pods, and mature pods. Field sampling showed that upper, immature pods are attacked with greater frequency than lower, more mature pods. In a greenhouse test, a slightly larger proportion of L6 larvae was recorded on inflorescences of rape plants during darkness than during light; the proportion of larvae found on the inflorescences was about 20%. Larvae pupated more quickly, formed heavier pupae, and gained more dry weight when fed exclusively from mid L4 on leaves than when fed mature or immature pods; mortality for larvae fed mature pods was 30% compared with none for larvae fed leaves or immature pods.The finding that pods are neither as preferred nor as adequate a dietary source as leaves is discussed in relation to the phenology of leaf retention of rape on the economic impact of bertha armyworm infestations.

The chemicals cis (Z) and trans (E)11-tetradecenyl acetate (11–14:Ac), trans 11-tetradecen-1-ol (E11–14:OH) and trans 11-tetradecenal (E11–14:Ald) were isolated from unmated female Choristoneura orae Freeman and shown to be highly attractive when used as lures in sticky traps. The identification of these components of the sex pheromone facilitates the separation of C. orae from other Pinaceae-feeding Choristoneura in the same area.

The behavioural responses of insects to insecticides and the relationships of these responses to physiological resistance are reviewed and discussed in terms of their potential economic importance and their genetic and evolutionary bases. In addition, responses to insecticide are compared with responses of phytophagous insects to host-produced toxins, with the discussion centring upon the genetic and evolutionary bases of these similar types of response and their possible roles in adaptation and speciation.

Probit analysis of the dosage response of first instar, fruittree leafroller larvae to azinphos-methyl indicated that a strain from a commercial orchard in East Kelowna, B.C. was 7.8 times more tolerant than a susceptible strain. Azinphos-methyl applied to experimental apple blocks in the same area did not provide satisfactory control. Leafroller damage as high as 10.5% was found in several orchards which had received multiple azinphos-methyl and other organophosphorous insecticide treatments. The development of an organophosphorous resistant strain of fruittree leafroller in this orchard area is strongly suggested. Bacillus thuringiensis applied at the pink stage of apple blossom development gave adequate control of fruittree leafroller in East Kelowna field trials and will be suggested as the control material for commercial orchards in this area.

A bioassay apparatus using an aquarium filter to maintain water flow and to minimize contamination with black fly larvicides was developed. The apparatus is fairly compact, provides good visibility of and access to the test organisms and is assembled easily from materials readily available. It can be operated in a flow-through or a recirculation mode and can be used to assess pesticide effects on non-target stream invertebrates.

Two-day-old females of Compsilura concinnata (Meigen) were exposed to hosts for several days after which their host-related behavior was observed. Parasites retained their preference for gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), larvae over greater wax moth larvae, Galleria mellonella (L.) (Lepidoptera: Pyralidae), whether conditioned to gypsy moths, wax moths, or no hosts. However, parasites conditioned to gypsy moth larvae examined and attacked hosts less frequently than those conditioned to wax moths or to no hosts. By exposing female flies to gypsy moth larvae for short times before tests and by dissecting them it was found that the number of progeny a female was capable of producing was not closely related to subsequent levels of parasite activity. Thus the activity differences appear to be behavioral rather than physiological in origin. The explanation appears to be that C. concinnata is unusually active when it first encounters a preferred host such as the gypsy moth. The invariance of the preference for gypsy moth larvae despite the exposure history of adult females means that C. concinnata probably could be reared on wax moths in the laboratory without concern that newly-emerged parasites might contact wax moths. They would still successfully attack gypsy moths in the field.

The effect of selected constant temperatures (15.6°, 21.1°, 26.7°, 32.2°, 37.8 °C) on oviposition, feeding, and longevity of Liriomyza trifolii (Burgess) was examined in the laboratory with chrysanthemum, Chrysanthemum morifolium Ramat, as a host plant. There was no significant difference in total feeding at 21.1°, 26.7°, and 32.2 °C nor was there significant difference in egg deposition at these temperatures. The ratio egg deposition: feeding was significantly larger at 26.7 °C. Longevity was similar (12–16 days) at all temperatures except 37.8 °C where it was reduced to ca. 3 days. The effect of temperature was more pronounced when feeding and oviposition were analyzed per day. Maximum feeding occurred at 32.2 °C while significantly more oviposition was found at 26.7 °C. An estimate of the threshold temperature for oviposition was 12.2 °C which was higher than that observed experimentally (10 °C). Ninety percent of oviposition occurred with 550°D of adult female life (above base 10 °C).

Wind tunnel experiments confirmed the optimum blend of the two major components of the sex pheromone of the spruce bud worm Choristoneura fumiferana (Clem.), (E)- and (Z)-11-tetradecenal, to be close to a ratio of 95(E):5(Z). The addition of two minor components, (E)-11-tetradecenyl acetate and the saturated tetradecanal, previously identified in the effluvia of calling virgin females, showed that the acetate alone reduced the level of some responses, while the addition of tetradecanal to the acetate:aldehyde blend restored response to previous levels. Addition of tetradecanal alone showed only minor effects on responses. Males responding to calling females showed higher levels of response and sustained flight longer than did males responding to the four-component blend, and this fact suggests that the blend is incomplete.

Bacillus thuringiensis var. kurstaki (B.t.) is the most widely used biological control agent against the spruce budworm, Choristoneura fumiferana (Clem.), a major defoliator of coniferous forests. The technology of applying the bacterium, however, is still not fully developed and the strategy of applying single or split applications of B.t. in unmixed stands is still in question. Double applications are generally accepted as necessary in mixed stands of white spruce, Picea glauca (Moench) Voss, red spruce, P. rubens Sarg., black spruce, P. mariana (Mill.) BSP, and balsam fir, Abies balsamea (L.) Mill., due to difference in the phenological development of the host trees and of the budworm infesting them. Field trials were conducted at Mine Centre, Ontario, to compare the efficacies of double and single applications of B.t. against the budwonn infesting balsam fir stands.

The sex pheromone of bertha armyworm, Mamestra configurata (Walker), was reported to be (Z)-11-hexadecenyl acetate (Z11-16:Ac) and an unidentified tetradecenyl acetate. Electroantennogram responses of male antennae to synthetic isomeric tetradecenyl acetates and attractancy tests under field conditions showed that the highest number of males were captured with a blend of Z9-14:Ac: Z11-16:Ac in a ratio of 1:19 (Underhill et al. 1977). This blend has been useful for monitoring the relative abundances of bertha armyworm; however, in 162 monitor traps in southern Alberta from 1979 to 1982, the catches consisted of 18.4% Agroperina cogitata (Sm)

The pecan weevil, Curculio caryae (Horn), is a native American species that was first described by Horn (1873) from specimens bred from hickory nuts at Brooklyn, New York. It has been regarded as an obligatory feeder on nuts of the genus Carya (Gibson 1969; Harris 1983), and is especially troublesome in commercial hickory nut and pecan orchards.