First-generation mullein bug, Campylomma verbasci (Meyer), nymphs damaged four major cultivars of apple in commercial and research orchards from 1982 to 1984. In commercial orchards, C. verbasci was ranked among the top three pests in 22 of 40 samples collected at harvest, and its damage exceeded the economic injury level of 1% culled apples in 17 of the samples. Injury was greatest in "Delicious" cultivars, for which a linear relationship was derived between population density and damage at harvest. Economic injury levels of one and four nymphs per tap are proposed for cvs. Golden and Red Delicious, respectively, in British Columbia.

Dioryctria reniculella may be occasionally found in abundance feeding on cones and foliage of spruce in Quebec. In this paper, the life history, habits, and description of immature stages as yet unreported in the literature are presented, along with short notes on populations and natural control organisms.

Predatory activity of Formica lugubris was studied from May through August 1976, to determine the variety of prey collected and the relative abundance of different groups of prey throughout the season. Prey consisted entirely of invertebrates, more than 95% being insects. Lepidoptera, especially Tortricidae, accounted for the major portion of prey during the sampling period. Using comparative rates of day and night prédation it was estimated that a large number of spruce bud worm were removed from the population by ant predators. It was also observed that prevailing weather conditions had a marked effect on predatory activity.

It has been generally accepted by insect microbiologists and physiologists that many insects harbour beneficial micro-organisms. The contributions of Buchner (1933), Glaser (1946), Jeanne1 (1949), Steinhaus (1946), Wigglesworth (1950) and Woodward (1949) are relevant. Some experimental evidence has been contributed by Aschner 1935, Blewett and Fraenkel (1944), and Brecher and Wigglesworth (1944). It seems that the micro-organisms may sometimes supply the host with vitamins of the B group. (Blewett and Fraenkel). Many species of insects have special organs, called mycetomes, whose chief function seems to be the housing of micro-organisms. Furthermore it has been suggested that special arrangements exist for the transference of micro-organisms from one generation of insects to the next. (Mansour, 1935; Murray and Tiegs, 1935; and Woodward 1949).

In an earlier laboratory study (Burnett, 1958) influences of various types of host distribution on the efficiency of the chalcid parasite Encarsia formosa Gahan were determined. A constant number of parasites searched among five host densities for scales of the greenhouse whitefly, Trialeurodes vaporariorum (Westw.), that were distributed in three patterns over a 25-square-inch surface. In addition to the increased parasitism resuItIng from contagious distributions of the host, it was found that approximately the same percentage of each of the five different host densities within the same distribution was attacked by the parasite.

Feeding preferences of the white pine weevil, Pissodes strobi (Peck), for resistant or susceptible Sitka spruce, Picea sitchensis (Bong) Carr., were investigated using three types of laboratory bioassay. In paired-twig bioassays, fall weevils were significantly deterred from feeding up to 80% by resistant clones from four British Columbia provenances: Green Timbers, Cedarvale, Haney, and Big Qualicum. Females showed greater discrimination than males. Spring weevils were deterred from feeding by clones from the Green Timbers and Big Qualicum provenances by up to 60%. Fall males were more consistently deterred than spring males, suggesting that some host selection occurs in the fall. Females were significantly deterred from ovipositing on twigs from one clone from Big Qualicum, and stimulated by clones from Cedarvale when given a choice. Given no choice, however, they were significantly deterred from ovipositing, but not feeding by several resistant clones. In agar-disc bioassays, spring weevils were significantly deterred from feeding by bark from the provenances of Cedarvale and Big Qualicum by up to 86%. Trees from the provenances of Big Qualicum and Green Timbers caused the most consistent feeding or oviposition deterrency and may rely on this in part as a resistance mechanism. Because not all resistant clones and provenances were deterrent, we hypothesize that these trees may employ other resistance mechanisms which could be incorporated along with feeding and oviposition deterrency into breeding for resistance.

We describe three new genera and four new species (three named) of siricomorph sawflies (Hymenoptera: Symphyta) from the Ypresian (early Eocene) Okanagan Highlands: Pamphiliidae, Ulteramus republicensisnew genus, new species from Republic, Washington, United States of America; Siricidae, Ypresiosirex orthosemosnew genus, new species from McAbee, British Columbia, Canada; and Cephidae, Cuspilongus cachecreekensisnew genus, new species from McAbee and another cephid treated as Cephinae species A from Horsefly River, British Columbia, Canada. These are the only currently established occurrences of any siricomorph family in the Ypresian. We treat the undescribed new siricoid from the Cretaceous Crato Formation of Brazil as belonging to the Pseudosiricidae, not Siricidae, and agree with various authors that the Ypresian Megapterites mirabilis Cockerell is an ant (Hymenoptera: Formicidae). The Miocene species Cephites oeningensis Heer and C. fragilis Heer, assigned to the Cephidae over a century and a half ago, are also ants. Many of the host plants that siricomporphs feed upon today first appeared in the Eocene, a number of these in the Okanagan Highlands in particular. The Okanagan Highlands sites where these wasps were found also had upper microthermal mean annual temperatures as are overwhelmingly preferred by most modern siricomorphs, but were uncommon in the globally warm Ypresian, only found then in higher elevations and highest latitudes.

Immature stages of the pea aphid, Acyrthosiphon pisum (Harris), from viviparous, parthenogenetic populations, were exposed to hot and cold temperatures outside the favorable zone. Between 34.5 °C and 41.0 °C, time to 50% mortality (LT50) decreased approximately according to the relation log Y = 10.30−0.22X. From −9 °C to −12 °C, LT50 decreased rapidly and changed little with further temperature decrease to −16 °C.

Survival was affected by acclimation which was complete after 1 to 2 days. Acclimation to temperatures between 10 °C and 25 °C changed LT50 by as much as 1.3 times at 39 °C and 2 times at −12 °C.

Temperature tolerance increased with age.

The efficacy of mixtures of chlordimeform with Bacillus thuringiensis and(or) Autographa californica nuclear polyhedrosis virus and Pieris rapae granulosis virus against Trichoplusia ni and Pieris rapae on the late cabbage was assessed in field plots over four growing seasons. Mixtures of 0.07 kg of chlordimeform/ha (1/8 of the recommended dosage) with low concentrations of the microbial insecticides were as effective or more effective than the materials used alone at full rates. The advantages of such mixtures in pest management are discussed.

Attractants were found for males of 12 moth species: Acronicta grisea Walker, Andropolia contacta Walker, Argyrotaenia dorsalana Dyar, Chrysaspidia putnami (Grote), Chrysaspidia venusta Walker, Eurythmia hospitella Zeller, Exartema appendiceum Zeller, Mutuuraia mysippusalis (Walker), Decodes horarianus Walsingham, Polia atlantica Grote, Sitochroa chortalis Grote, and Pandemis canadana Kearfott. For five of these species single pure compounds were useful attractants, while the remaining seven required binary mixtures whose components when tested singly showed little or no attractancy.

Atmospheric permeation of apple orchards with 16:1 butyl butyrate (BB): 2(E)-crotyl butyrate (CB), the sex pheromone of the mullein bug, Campylomma verbasci (Meyer) (Heteroptera: Miridae), demonstrated potential for pheromone-based mating disruption; atmospheric permeation with single components did not. In traps baited with 16:1 BB:CB, catches of male C. verbasci were 3, 64, and 105% of catches in nontreated controls for disruption treatments of 16:1 BB:CB, CB alone, and BB alone, respectively. With the two-component pheromone as a disruptant, catches of male C. verbasci were significantly reduced relative to controls at dispenser densities of 250, 500, and 1000 per hectare; catches were lowest at 1000 dispensers per hectare. For monitoring of operational trials, pheromone-baited open wing traps hung 1.5 m above ground were judged to be more practical than open wing traps hung 2.5 m above ground, or closed wing traps or white sticky cards at either height. Atmospheric permeation with pheromone did not affect numbers of males and females captured on nonbaited white sticky cards, and trap height did not affect catches of females. However, in pheromone-treated plots, significantly more males were captured on 2.5-m-high nonbaited cards than on 1.5-m-high cards, probably representing incidental catches of males following false trails to pheromone dispensers hung in the upper canopy. This study is the first reported example of pheromone-based disruption of orientation behavior in the Heteroptera.

The apple rust mite, Aculus schlechtendali (Nal.), is active on the apple leaves from late May until early August and passes through three generations as indicated by the peak numbers of eggs. This species overwinters as deutogynes under bud scales and crevices in the bark. During the latter part of May the deutogynes lay eggs that develop into first generation primaries, followed by a second generation the latter part of June. Eggs laid by the second generation primaries produce the overwintering deutogynes. Injury to the leaves, mainly bronzing to the ventral surfaces, becomes noticeable early in July. The numbers of A. schlechtendali varied between cultivars within orchards. The differences were not consistent between orchards.

Eggs of western tent caterpillars hatch just as leaves of their food plants are developing. To determine the impact of asynchrony between leaf development and egg hatch during a year of peak density and the initiation of decline, egg masses were introduced to four study areas after the time of normal egg hatching. Survival of caterpillars was not significantly influenced by delays of 3–6 weeks in hatching. Populations composed primarily of introduced insects and control populations declined following the summer of the experiment. Although hatching of deployed eggs was delayed, caterpillar development during warmer temperatures later in the spring was sufficiently rapid that caterpillars from all groups reached the fifth instar by mid-June, and parasitization of caterpillars from control and experimental areas was similar. Tent caterpillar survival was apparently resilient to substantial delays in egg hatch which suggests that cyclic population declines are not likely to be associated with minor variation in the synchrony of leaf development and egg hatch.

The developmental rates of individual larvae of Tribolium confusum Jacquelin duVal were measured at five temperatures on three diets to quantify the interaction between these two environmental factors. No significant differences in survival were detected but developmental times were affected by both factors. A logistic equation accurately described the relationship between mean developmental rate and temperature for each diet. The variance in developmental rate was a linear function of the mean developmental rate, and the mean accounted for more of the differences in variance than diet or temperature.

The effect of diet was greatest at the temperature which caused the highest developmental rate. It decreased as temperature decreased. This effect could be accounted for by varying the coefficient K, the asymptote of the logistic equation. The coefficient K showed a positive linear relationship to the lysine content of the diet. This coefficient may provide a compact and quantitative means of summarizing the interaction of environmental factors such as diet and temperature in the logistic model for the developmental rate of insects.

The effect of host age of the cabbage looper, Trichoplusia ni (Hübner), on ovipositional rate and successful parasitism by Hyposoter exiguae (Viereck), a solitary endoparasitoid was investigated. Success in parasitism of T. ni was correlated with host age. Successful parasitism of hosts exposed as first, second, or early third instar larvae, ranged from 83 to 88%. A decline in parasitism was observed for the remaining instars with a low of 27% for mid-fifth instar larvae.

A different relationship between host age and successful parasitism was observed in tests where all five instars of the host were presented to the parasitoid simultaneously. Successful parasitism was highest among second and third instars, approximately 75% for both, and lowest for fifth and first instars, 10% and 30%, respectively. A significantly higher rate of mortality was found for first instar hosts.

The ovipositional rate of H. exiguae was related to host age. The parasitoid deposited an average of 2.3 and 1.3 eggs per 24 h in first and second instar T. ni, respectively The number of eggs/host and degree of superparasitism declined in older individuals and differed statistically for each instar. The percentage parasitism differed statistically for all but first and second instar larvae.

It was hypothesized that Delia antiqua (Meigen), the onion fly, would show high preference in the field for trap colors reflecting visible wavelengths between 400 and 480 nm at reflective intensities above 37%. This preferred spectral zone (PSZ) was tested in an onion field in 1984, using cardboard traps painted with 11 blue, violet, and green hues, and two PSZ reflecting colors of varying intensity. It was found that colors with peak reflective wavelengths occurring between 400 and 470 nm, at or above 30% reflectance intensity, were most preferred. Wavelength-specific reflectance intensity was shown for the first time under field conditions to influence the magnitude of color preference in the onion fly.

The acute toxicities of an extract obtained from a plant within the Piperaceae family and related synthetic analogues were tested against four common Canadian forest pest insects. The acute toxicity of the extract from black pepper, Piper nigrum L., was assessed after 1, 24, and 72 h by the percent larval mortality. The 24 h LC50 estimates for the P. nigrum extract were (in order of decreasing sensitivity) 0.012% for the introduced pine sawfly, Diprion similis (Hartig) (Hymenoptera: Diprionidae), 0.053% for the forest tent caterpillar, Malacosoma disstria Hubner (Lepidoptera: Lasiocampidae), 0.282% for the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), and 0.998% for the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Torticidae). There was no significant increase in mortality after 72 h. Seventy percent of L. dispar larvae dropped off or moved from branches within 1 h of application of 0.2% P. nigrum extract, indicating that these compounds have a repellent effect. Pipercide and nor-pipercide were more toxic to L. dispar and M. disstria larvae than piperolein A and a P. sarmentosum Roxb. amide 72 h after either oral or topical administration of these compounds. Toxic effects of piperamides were more pronounced by oral ingestion. Ninety percent mortality of L. dispar larvae occurred following an oral dose of 5 µg pipercide in diet, whereas mortality was only 40% following topical treatment at 5 µg pipercide/insect. Whole Piper extracts might be useful for the control of sawflies and tent caterpillars in small-scale applications, based on the demonstrated efficacy and reduced risk potential.

Continued range expansion of Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is exposing new species of soft fruits and berries to potential infestation. Our understanding of cues that drive host-finding and selection in this highly polyphagous pest insect is still incomplete. Fruit firmness influences host choice behaviour by limiting suitability for oviposition and larval development. Other factors such as fruit sweetness and acidity act as cues for fruit ripening. Here we assess the role of these cues and fruit colour on host selection. We demonstrate that the use of objective and nonanthropocentric methods of quantifying colour in studies of colour preference is critical to understanding the cues evoking responses from insects. Acidity but not sweetness increased D. suzukii attraction and larval success. Differences in D. suzukii attraction were most strongly correlated with short-wavelength reflectance (blue, cyan, and green (470–560 nm)). Growers could select for fruit varieties with relatively higher reflectance values upon maturity to reduce susceptibility to D. suzukii.

In the study of insect parasites of the darksided cutworm, Euxoa messoria (Harris), fourth- to seventh-instar larvae were collected from a field at Delhi, Ont., and reared in the laboratory. A total of 701 insect parasites including six species of Hymenoptera and four of Diptera, were reared from the 3970 darksided cutworm larvae collected in 1973 and 1974.

Thirteen species of insect parasites of E. messoria are listed. Ten of these species were reared in the present study from E. messoria in Ontario and all of them are primary and internal parasites. Of the 10, only two have previously been reported as parasites of E. messoria. Host–parasite relationship and the degree of parasitism are given for the 10 species reared in Ontario.