Relationships between mean egg weight and overwintering survival in the laboratory were explored in selected large- and small-egg lines and also in first laboratory generations from 5 widely separated locations. Overwintering stress was provided by prolonged storage or above average storage temperature. Under stress large eggs were shown to have greater survival than small eggs in both stocks of insects. The results explain why spruce budworm from higher latitudes (longer winters) have heavier (larger) eggs. Other effects of prolonged storage and storage selection on subsequent size and development rates in both the treatment and the F1 generations are reported.

Both Petrova albicapitana (Busck) and P. metallica (Busck) attack Pinus contorta Dougl. in Alberta. The similarity of their larvae and of the pitch-blister nodules that they construct make it difficult to identify the 2 species in the field; however, they can be separated on the basis of their feeding damage. The abundance of males caught in pheromone traps indicates that P. metallica was more common than P. albicapitana in 1981–1984, and more widely distributed than previously recorded in Alberta. The examination of the feeding damage and the pheromone trapping of males indicate P. metallica occur only in stands of P. contorta in Alberta. Petrova albicapitana, however, was collected in stands of P. contorta, P. banksiana Lamb., and a mixture of P. contorta and P. banksiana. The 2 species differed in seasonal occurrence and abundance at different elevations.

Observations on Malus domestica (Borkh) in central Ontario between 1981 and 1984 revealed that dogwood borer (Synanthedon scitula Harris) larval feeding was primarily associated with burr knots on the above-ground portion of apple rootstocks. Trunk injuries also served as sites of entry. Monitoring with pheromones indicated moth emergence occurred from late June until early August with peak activity occurring near the middle of July. Control of the dogwood borer on apple was obtained with 2 trunk drench sprays of dimethoate, fenvalerate, permethrin plus oil, endosulfan, parathion, chlorpyrifos, or lindane when applied during the period of adult flight activity.

Emergence from hibernacula of 2nd instars of Choristoneura occidentalis was more variable but later than that of C. retiniana. However, early-instar development was faster in C. occidentalis and compensated for the difference in emergence times so that both species entered the 6th instar simultaneously. There were no species-related differences in development beyond the 6th instar. Though they have different resource-tracking patterns early in their life cycle, temporal isolation between these species is unlikely. No developmental morphs were found in either species but there were several instances where individuals that developed at an increased (or decreased) rate in one stage developed slower (or faster) than the mean rate in a substantial stage. Negative correlations between development times were indicative of this. These correlations reduced variation in adult eclosion times induced by extended spring emergence and are indicative of homeostasis in development within populations. Negative correlation coefficients between development periods were more common in C. occidentalis, which also had the more variable spring-emergence pattern. Hybrids were intermediate in almost all development traits.

Field-screening tests using dodecenyl and dodecadienyl acetates and alcohols were conducted in pine plantations in northern Ontario to find attractants for Rhyacionia and Eucosma moths. Rhyacionia adana was attracted by various ratios of (E)-9-dodecenyl acetate and (E)-9-dodecen-1-ol (99:1 to 70:30) but no clear preference was observed. Similarly, R. busckana was also attracted to the same ratios of these compounds. Rhyacionia granti Miller, a new species revealed by these tests, was attracted to (E,E)-8.10-dodecadienyl acetate. Rhyacionia granti and R. busckana are newly recognized sibling species distinguished in this study by differences in their respective attractants, EAG responses, and phenologies. The fourth species studied. E. gloriola, was optimally attracted by 9:1 and 8:2 ratios of (Z)-9-dodecenyl acetate and (E)-9-dodecenyl acetate. Flight data for the 4 species in the same plantation revealed overlapping flight periods. Rhyacionia granti was the earliest flier, followed closely by R. adana and R. busckana, and somewhat later by E. gloriola.

Bassus arthurellus n. sp. is described making the name available for studies currently underway on the parasitoids of pests of sunflower (Helianthus). Reasons are given for including this species in Bassus F., a genus often considered a synonym of Agathis Latr.

The preference of the nabid, Reduviolus americoferus (L.), for potato leafhopper nymphs, Empoasca fabae (Harris), and pea aphids, Acyrthosiphon pisum (Harris), was examined using functional response models. The nabid exhibited a type-II functional response to each prey. Handling time was much higher for the aphid than for the leafhopper (3.623 vs. 0.211 h). Instantaneous search rates were also higher for the aphid (0.096 vs. 0.020 h−1). A preference index was calculated using the ratio of the instantaneous search rates. The nabid exhibited strong preference for the aphid; when both prey were present in equal numbers, the nabid consumed 3 times as many aphids. The predator did not switch to leafhopper nymphs as the proportion of leafhoppers was increased.

The activity of native and domestic insect pollinators was studied for 3 consecutive years, during the blossom period in a semi-dwarf apple orchard of the Niagara Peninsula. Insect numbers and activity were correlated with apple cultivars (Empire, McIntosh, Golden Delicious, Red Delicious) located on the east and west slopes of the orchard and with temperature, humidity, and light intensity fluctuations. The physical factors, especially temperature, were mainly responsible for the variation in the numbers of honeybees. Factors such as cultivar, east and west slopes, and year were more significant for native pollinators. Native pollinators less affected by adverse conditions seem to compensate for reduced honeybee activity during unfavorable years.

A typical lake outlet of the Canadian Shield was treated for 15 min with a high dose (5.28 g/L s−1 of discharge) of Teknar®, a commercial formulation of Bacillus thuringiensis serovar. israelensis. Efficacy on Simuliidae larvae and impact on non-target aquatic insects of this stream were monitored using drift nets, counting plates, and artificial turf substrates along a 1000-m section downstream of the site of application. Compared with a 4-day pre-treatment average for 12-h sampling periods, drift of Simuliidae increased from 64 to 92 ×, with shorter peaks of 133–184 ×, 2–6 h after treatment. There was no evident drift increase in larvae of Ephemeroptera, Plecoptera, Trichoptera, Chironomidae, or dipterous pupae, but larvae of Blephariceridae (Diptera) were severely affected as their drift was increased by up to 50 × and remained high for 3 days. After 30 h the mortality of Simuliidae on counting plates ranged from 95 to 82% in the first 300 m, with detachment rates of 78.5–46.5%. Densities of non-target insect larvae were not reduced on the artificial substrates, except for 2 genera of Chironomidae (Eukiefferella and Polypedilum) which were reduced 26 to 39% of their original density. Drifting larvae of 1 chironomid genus (Phaenopsectra) also showed symptoms of toxemia by B.t.i. The main impact of the treatment was thus seen in 2 Nematocera families (Chironomidae and Blephariceridae) which were mainly exposed to B.t.i. sedimented on the bottom of the stream or attached to periphyton growing on rocks.

To test the hypothesis that bark beetles and some associated insect species are attracted to ponderosa pines infected by Ceratocystis wageneri, insect visitations on 11 severely diseased, 9 moderately diseased, and 10 apparently healthy trees were monitored from 1 August to 15 October 1972. Larger numbers of Dendroctonus brevicomis, D. ponderosae, Temnochila chlorodia, and buprestids were captured on diseased trees uninfested by bark beetles than on apparently healthy ones, thus possibly indicating attraction to diseased trees. There was strong evidence that D. valens and Spondylis upiformis were attracted more frequently to wounds on diseased than on healthy trees. Arrival patterns of beetles were recorded for trees that became infested during the study. Predators became abundant on traps as bark beetle catches increased.

Elymana sulphurella (Zetterstedt) is confirmed as an introduced European species, and is distinguished from its relatives in the New World, including 2 new species E. circius (British Columbia to Saskatchewan) and E. pacifica Hamilton (British Columbia). Elymana acrita DeLong 1936 is synonymized with E. acuma DeLong 1936, and E. caduca DeLong 1936 is synonymized with E. inornata (Van Duzee 1892). A key to the New World species is presented. A method of rearing E. sulphurella in a controlled environment is described. Of 11 plant species tested as food hosts, Agrostis gigantea Roth., Elymus glaucus Buckl., Festuca arundinacea Schreb., F. elatior L., F. rubra L., and Phleum pratense L. were suitable for nymphs and adults, Lolium perenne L. for nymphs, and Alopecurus pratensis L., Bromus inermis Leyss., and Dactylis glomerata L. for adults. Digitaria sanguinalis (L.) Scop. and Echinochloa crus-galli (L.) Beauv. were unsuitable for both stages. Ten of 11 plant species tested as oviposition hosts yielded nymphs but the numbers varied widely. Leaf blades were preferred over sheaths as oviposition sites and most eggs were laid in the lower two-thirds of the leaf. Eggs appeared to be in diapause when laid and required several months to hatch if held at room temperature. Cold treatment of such eggs decreased the minimum hatching time and reduced the period over which hatching occurred. The mean developmental period of females was 24.9 days and males 23.5 days. The mean longevity of mated females (83.2 days) was significantly (P = 0.05) longer than that of males (62.1 days).

The effect of trap color on sticky-trap catches of Pholetesor ornigis Weed was studied in experimental and commercial apple orchards during each of the parasite's 3 yearly activity periods during 1982–1984. Seven enamel and 5 fluorescent paints were compared in 8 trials. There was considerable between-trial variation in the percentage of the total number of P. ornigis caught on a trap of one color. Trap color had a significant effect on the total number of parasites caught. There were no consistent differences in the relative attractiveness of the different colors to males and females. During 1984, males comprised more than 75% of all parasites trapped during each of the 3 activity periods. The sex ratio of the adult population emerging in study orchards during 2 of these activity periods was approximately 1:1.

Sticky traps are commonly used for monitoring insects in studies of their ecology (Southwood 1966) and in programs to manage their numbers (Flint and van den Bosch 1981). These traps may intercept flying insects or may visually attract insects over a distance (Southwood 1966). The relative sensitivity of an insect eye to different wavelengths of light may differ among species (Wigglesworth 1972) and therefore color can affect the quality and magnitude of trap catches (Prokopy and Owens 1983; Southwood 1966). The effect of color on trap catches therefore is often the first step in evaluating trapping methods for use in monitoring insects. Insects attracted to and landing on colored traps are retained by paint- or spray-on adhesives that have been developed specifically for this purpose. This paper reports on the effect that one of these adhesives has on the spectral reflectance of colored traps.

The existence of a diurnal cycle in the rate of production of acoustic signals by aquatic heteropterans has been observed by several workers (Leston 1955; Mitis 1936; Schaller 1951; Theiss 1983). These accounts all mention an increase in acoustic activity in early evening. Jansson (1968, 1973) determined that the single strongest component releasing acoustic behavior was light level in the genera Cenocorixa and Callicorixa and that different species of Cenocorixa had different maxima. The study reported here began as an examination of diel periodicity of song incidence in the corixid bug Palmacorixa buenoi but results were substantially different in kind from most other studies of this nature in the literature.

Parasitization of larch casebearer, Coleophora laricella (Hübner), by the internal larval parasite, Agathis pumila (Ratz.), commonly has been found to decrease between successive samples in the spring. The decrease has been attributed in part to mortality of A. pumila, which prolongs the casebearer's larval stage, thereby exposing it to subsequent parasitism by other species that are intrinsically superior (Smith 1929) and to secondary parasitism of A. pumila (Graham 1949; Quednau 1970; Raske and Schooley 1979; Ismail and Long 1982). Another reason may exist for this decrease in parasitization by A. pumila: A higher percentage of parasitized than unparasitized larvae may descend from the larch foliage to the understory vegetation, which is not in the normally sampled universe (Webb 1953; Moody 1977; Denton 1979; Long and Theroux 1979; Ryan 1983). Eidmann (1965) reports that casebearers are often found on the undergrowth when high populations strip the trees, but prior to this no one had reported any connection with parasitism. This movement may result in a decreased percentage of parasitized larvae remaining on the larch foliage. Evidence presented here substantiates this hypothesis for one location, but for a more general conclusion other areas should also be examined.

The deodar weevil, Pissodes nemorensis Germar, is a vector and wounding agent associated with pitch canker fungus, Fusarium moniliforme Sheld. var. subglutinans Wr. & Reink., in the southeastern United States (Blakeslee et al. 1981). This univoltine weevil breeds in southern pines that have been stressed by factors such as fire, lightning, or mechanical injury (Baker 1972). The adults feed on phloem after chewing through the outer bark. Females deposit eggs in some of these feeding pits and then plug the hole with macerated phloem (Atkinson 1979). Larvae tunnel under the bark and feed on phloem as they develop.