The mullein bug, Campylomma verbasci (Meyer) (Heteroptera: Miridae), was studied in and around 17 apple orchards in the Okanagan Valley during 1982–1984. Apple and pear were overwintering hosts and the principal perennial hosts during summer months. Campylomma verbasci was the most abundant mirid on apple and occurred in 16 orchards, with two or three generations per year. Nymphs first emerged from overwintered eggs near full bloom, but variation in timing occurred between orchards and years. Population densities of C. verbasci were higher (P<0.05) in unsprayed than in sprayed orchards, but no differences were observed between commercial and “organic” orchards. In June, some adults moved onto herbaceous plant hosts, primarily common mullein, Verbascum thapsus L. Two generations of C. verbasci were found on mullein and the bugs were distributed in an aggregated pattern. Significant associations occurred among height, raceme length, or flower number of mullein plants and the number of C. verbasci on them. From mid-August to October, adult numbers declined on mullein and increased on apple. The number of mullein plants per orchard was not always associated with the density of overwintered C. verbasci in the following year.

Six of the nine most common indigenous species of noctuid moths caught in a light trap at Glenlea, Man., over an 11-year period were univoltine and three were typically bivoltine but sometimes trivoltine. For the univoltine species, the day of peak catch and the day of 50% catch differed only by 3 days or less during 11 years. The timing of flight periods of Feltia jaculifera (Gn.), F. herilis (Grt.), Agrotis venerabilis Wlk., and Nephelodes minians Gn. were not influenced by the degree-days above 10 °C and the standard deviation of the date of 50% catch for these species was within 5–6 days. The date of 50% catch was more variable for Crymodes devastator (Brace) and Euxoa ochrogaster (Gn.), and the variation for the latter was partly explained by a relationship between flight dates and accumulated degree-days above 10 °C. For the multivoltine species, Pseudaletia unipuncta (Haw.), Discestra trifolii (Hufn.), and Xestia adela Franc., the day of peak catch for two generations also varied little from the day of 50% catch for each generation, but the day on which peaks occurred varied from year to year. Only for the first generation of D. trifolii was the day of 50% catch correlated with accumulated degree-days over 10 °C. Moth numbers for each species were not necessarily high when there were reports of crop damage by their respective larvae. There was no correlation between catches of moths in the first and second generation of multivoltine species, and there were no patterns of population trends among any of the economically important species. The life history, feeding habits, and economic importance of each species are discussed.

Diptychophora huixtla from Chiapas, Mexico, and Diptychophora powelli from Guerrero, Nayarit, and Oaxaca, Mexico, are described as new species. The two species can readily be distinguished from each other and from other Diptychophorini by their wing patterns and features of the genitalia.

A temperature-dependent multiple cohort simulation model was used to predict emergence of western corn rootworms, Diabrotica virgifera virgifera LeConte, from the soil. Hourly 10-cm-depth soil temperatures were used as input to the model. Hourly soil temperatures were predicted from daily minimum and maximum 10-cm-depth soil temperatures using a half-sine-wave approximation, or from minimum and maximum daily 1-m-height air temperatures using a model for predicting soil temperature from air temperature. The mean difference in the number of days between predicted and observed 50% emergence was 0.22 days using soil temperatures and 0.00 days using air temperatures. Linear regressions of predicted versus observed Julian dates of 10, 50, and 90% cumulative beetle emergence from the soil indicated that model predictions were reasonably accurate and precise using both soil and air temperatures.

This study examined the dose-dependent effects of synthetic honey bee queen mandibular pheromone on the inhibition of worker ovary development. The range of doses examined was from 10−3 to 10 queen equivalents (Qeq) per day for 43 days; 1 Qeq was the amount of pheromone in an average pair of queen mandibular glands. Ovary class and ovariole number scores were used as estimates of worker ovary development. Queen mandibular pheromone did not inhibit ovary development in workers at any dose.

Qualitative and quantitative changes in the neutral lipid content of hemolymph of gypsy moths, Lymantria dispar L., were assayed in larval, pupal, and adult stages. The major neutral lipid constituents of the hemolymph were 1,2-diacylglycerols and ranged in nominal concentration from 1.6–3.4 (larval), 3.1–4.9(pupal),toamaximumof 19.3 μg lipid per microlitre hemolymph in the adult male. When detected, triacylglycerols and monoacylglycerols never exceed diacylglycerol concentrations. The fatty acid composition of 1,2-diacylglycerols from adult male moths (0–12 h after emergence) was determined as fatty acid methyl esters using gas chromatography/mass spectrometry analysis. Nine fatty acid structures have been assigned. Of these, five are saturated, unbranched, aliphatic fatty acids (C14:0 – C18:0) which comprise 80.5% of the total fatty acid abundance. The remaining four fatty acids consist of two saturated, methyl-branched, aliphatic compounds, a mono-unsaturated aliphatic acid, and a tri-unsaturated, tricyclic, diterpenoid acid.

A wide range in feeding damage as defined by leaf scars among 27 cultivars of florist’s chrysanthemum was apparent for the western flower thrips, Frankliniella occidentalis (Pergande). Assessments based on numbers of feeding scars or ranking of cultivars on the basis of the leaf area damaged by feeding were in close agreement. Cultivars with the most feeding damage under growth room conditions, such as cvs. White Marble and Polaris, were the same as those in plots within a naturally infested commercial greenhouse. Under growth room conditions, a 2- to 4-week exposure of plants to a population of thrips was sufficient to evaluate feeding damage. Closely related cultivars had similar levels of feeding damage, and foliage of yellow-flowered cultivars was significantly more attractive to thrips for feeding than foliage of white-flowered sister cultivars during the pre-bloom period. There was a low correlation between feeding damage and incidence of the tomato spotted wilt virus among cultivars in both growth room and greenhouse tests, indicating that virus susceptibility of cultivars was epidemiologically more significant than the feeding activity of western flower thrips.

The effects of trap design, lure concentration, lure age, and trap maintenance on the catch of western spruce budworm moths, Choristoneura occidentalis Freeman, in pheromone traps were tested in light to moderate infestations near Ashcroft, B.C. High cumulative moth catches reduced the trapping efficiency of both the sticky traps and the non-sticky Uni-traps relative to traps from which the moths were removed every 2 days. Correlations between the total season’s catch and larval density per plot in the same and following generations were not significant (P>0.05) for any of the eight combinations of trap design, lure concentration, and maintenance regimen tested. However, by dividing the mean moth catch in Uni-traps by either the basal area or foliage biomass per hectare in each plot, correlations with the following year’s larval density were significant (r 2 = 0.77–0.98; P<0.05; n=5).

The male meiotic karyotypic formula of Conophthorus coniperda (Schwarz) (Coleoptera: Scolytidae) is 9AA + XY. This karyotype differs from C. resinosae Hopkins and C. banksianae McPherson, both of which have the karyotypic formula of 8AA + XY. Supernumerary chromosomes were found in different populations of C. resinosae and C. banksianae but were absent in C. coniperda. No geographic variation in the karyotypes of the three species was observed. The karyotypic formulae confirm the designations of C. coniperda and C. resinosae by morphological characters, but do not support the designation of C. banksianae as a distinct species.

Data from larval head capsule measurements are used to determine allometry of size for final-instar siblings Simulium truncatum (Lundström) (= EFG/C) and S. rostratum (Lundström) (= ACD) of the S. venustum/verecundum complex (Diptera: Simuliidae). Measurements were evaluated using principal axis and major reduced axis regression. Isometry of size was accepted for only some ratios and it is argued that a character’s “environmental stability” should be assessed before it is considered as a taxonomic character.

Solanum berthaultii Hawkes bears trichomes reportedly providing resistance to insects. Results indicated that the density of types A and B trichomes was linearly related to the inverse of the leaflet area. The number of trichomes on the adaxial and on the abaxial surface of terminal leaflets was not affected by two levels of water stress or by growing conditions in the greenhouse or the field. The leaflets of the water-stressed plants were generally smaller and, consequently, the density of trichomes higher.

The survival of first-instar Colorado potato beetle larvae was similar on S. berthaultii grown under varying drought conditions and on leaves from field-grown plants bearing different densities of trichomes.

Podisus sagitta (Fab.) is a small- to medium-sized predatory stink bug, which is distributed from the southern United States into South America. The immature stages and both sexes of the adult insect from a laboratory strain are described and illustrated. Notes on the life history of P. sagitta also are given.

Pitch canker, caused by Fusarium subglutinans (Wollenw. and Reink.) Nelson, Toussoun, and Marasas, a pine pathogen recently identified in California, may increase the distribution and abundance of Ips spp. on Monterey pines in Santa Cruz Co., CA. In all pine stands, Ips spp. tunneled into healthy branches and boles. Ips mexicanus (Hopkins) was the most abundant engraver beetle observed, followed by I. paraconfusus Lanier; I. plastographus (LeConte) was rare. Ips mexicanus was routinely captured in traps baited with racemic I. paraconfusus pheromone. During die winter, I. mexicanus excavated mass feeding cavities in shade-suppressed branches. In uninfected stands, 3% of the trees and only 0.3% of the branches were mass-attacked. In severely infected stands, 47% of the top one-third of the trees, 3% of all branches, and 91% of the branches declining due to infection by F. subglutinans were mass-attacked by Ips spp. On pitch canker-infected trees, I. mexicanus attacked cones and stems <1 cm in diameter. Sixty percent of the attacks on logs occurred inside or within 5 cm of the area covered with pitch canker-induced resin. When confined with logs, 45% of I. paraconfusus tunneled in or near pitch canker-induced resinous areas,21% near fresh chisel wounds, and 19% near resinous material produced by the Sequoia pitch moth. Synanthedon sequoiae (Hy. Edwards).

Summary life table data of historical spruce budworm, Choristoneura fumiferana (Clemens), populations from the Green River Project in New Brunswick, Canada (1947–1958), provided information for developing a management strategy using annual inundative releases of the egg parasite Trichogramma minutum Riley. Three threshold levels (39, 169, and 201 budworm egg masses per 10 m2 foliage) were assigned to the spruce budworm population and a simulation model employed to manage it at or below each level. Based on field data, the lowest threshold represented a light level of defoliation while the other two thresholds represented moderate defoliation levels. With the exception of 3 years at the low level, annual inundative releases of T. minutum successfully suppressed the spruce budworm population below the three thresholds in the model. Annual releases of T. minutum were also simulated during the inclining, plateau, and declining phases of one outbreak cycle of the spruce budworm. At the same rate (12 × 106 female T. minutum per hectare), inundative releases during the inclining phase were more effective than during either the plateau or declining phases. The results suggest that some low and moderate populations of spruce budworm can be effectively managed using annual inundative releases of an egg parasite, particularly toward the end of the inclining phase of an outbreak, but when populations reach severe levels, additional mortality agents probably will have to be considered in an integrated approach.

2,4-Dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), the major hydroxamic acid present in corn root, was studied for its effects on western corn rootworm, Diabrotica virgifera virgifera (LeConte). Exogenously applied DIMBOA caused mortality in western corn rootworm larvae feeding on fresh corn roots. The LC50 (lethal concentration for 50% mortality) value (fiducial limits) was 153 ppm (108–209) and the LC90 value was 917 ppm (560–2297). The deleterious effects of DIMBOA on western corn rootworm larvae possibly are due to both feeding deterrence and toxicity. In a replicated pot trial during two growing seasons, two corn lines developed by Agriculture Canada from CIMMYT collections, ITR 3872 with high DIMBOA content in roots, and NTR-2 Ger. 4042 with low DIMBOA content in roots, were evaluated for resistance to western corn rootworm larvae. The results indicated that the high DIMBOA line (but not the low DIMBOA line) stressed western corn rootworm larvae to produce inferior adults based on the measurement of adult emergence number, adult weight, and adult head-capsule width. The effect of western corn rootworm on both corn lines with different DIMBOA levels was measured based on plant growth parameters including plant height, stem thickness, plant fresh weight, root fresh weight, plant dry weight, and root dry weight. ITR 3872 (high DIMBOA) showed significantly less damage than NTR-2 Ger. 4042 (low DIMBOA) in almost all plant parameters measured. The results suggest that DIMBOA may in some instances contribute to the resistance of corn to western corn rootworm larvae.

Exposure of adult rusty grain beetles, Cryptolestes ferrugineus (Stephens), saw-toothed grain beetles, Oryzaephilus surinamensis (L.), and red flour beetles, Tribolium castaneum (Herbst), to filter papers treated with the organophosphorus insecticides malathion or chlorpyrifos-methyl often affected offspring production in survivors. Groups of five male and five female survivors were placed on ground wheat at 30°C and C. ferrugineus and O. surinamensis adults produced fewer offspring with prolonged exposure to chlorpyrifos-methyl; malathion had no effect. Tribolium castaneum adults produced significantly more offspring with increasing exposure to both malathion and chlorpyrifos-methyl indicating stimulation of oviposition or a selection for increased fitness in survivors.

A comparison of the effects of infestation by known numbers of pea aphids, Acyrthosiphon pisum (Harris), on six field pea cultivars was made in field cage tests. The largest population of aphids developed on the cultivar Trapper and the smallest on the cultivar Century, with differences in aphid numbers between these cultivars significant for mature plants. Infested plants of Trapper had a significantly lower number of pods per plant, and infested plants of all cultivars had decreased seed weights, both per metre row and of 250 seeds, when compared with control plants. In all cultivars except Trapper, the most severely affected yield component was weight of 250 seeds.

Pea aphids, Acyrthosiphon pisum (Harris), were sampled weekly or biweekly over the summers of 1985 and 1986 in a total of 15 commercial plantings of Century, Trapper, or Triumph field peas across Manitoba. Pea aphid populations rose more quickly in fields of Trapper than in Century or Triumph fields. The owners of all Trapper fields sampled initiated aerial application of insecticide for pea aphid control; at the time of spraying in 1985, plants in Trapper fields had significantly greater numbers of aphids in sweep samples than such samples from Century or Triumph fields. In 1986, Triumph plants supported greater numbers of aphids than Century or Trapper plants. Triumph plants remained green longer than plants of the other cultivais; in 1985 pea aphid numbers on this cultivar were highest on the last date sampled.

Yield components were measured in sprayed and unsprayed plots within the commercial fields. When data were averaged for each cultivar, there were no significant differences in yield per area or in 1000 seed weight between sprayed and unsprayed plots. Data indicated that existing economic thresholds are too low for Trapper peas. However, one of the fields of Trapper peas that we sampled had significantly reduced numbers of pods per plant, yield per square metre, and weight of 1000 seeds in the unsprayed plot; this field had the largest population of pea aphids of any field sampled, with aphid numbers peaking at 48.5 ± 9.2 (SE) per plant lip during pod formation and filling. Significant yield losses also occurred in unsprayed plots of a Triumph field, which had a peak aphid population of 4.8 ± 1.6 per plant stem at pod maturation.

Studies were conducted from 1985 to 1988 in commercial corn fields distributed throughout the main corn growing areas of Manitoba to determine the distribution, phenology, and the level of infestation of the European corn borer, Ostrinia nubilalis (Hübner). Pheromone and blacklight traps were used to monitor the flight activity of European corn borer throughout the flight period. The level of European corn borer infestation was determined by sampling for egg masses, hatched egg masses, plants with egg masses, plants with shot holes, larvae, and stalk breakage. Results indicated that the European corn borer infestation occurred throughout the corn growing areas of Manitoba and that the population has declined from 1985 through 1988. Significant positive correlations existed among the number of egg masses, plants with egg masses, plants with shot holes, larvae per plant, and plants with broken stalks. Peak capture of moths in pheromone traps occurred well after peak oviposition, and 10–14 days after the peak blacklight trap capture. Blacklight trap catch, but not the pheromone trap catch, was positively correlated with egg mass density. Both blacklight and pheromone traps were equally efficient in determining the onset and the duration of European corn borer flight, although for initiating surveys of egg masses and shot hole damage, pheromone traps are recommended. In Manitoba, corn growers apply pesticides well before the recommended damage threshold is reached.

In Ontario several species of polyphagous arthropods consumed nymphs and apterous adults of the green apple aphid, Aphis pomi DeGeer, as determined by serological assays and feeding trials. The most abundant predators on apple tree foliage were the reduviid Acholla multispinosa L., the mirid Campylomma verbasci (Meyer), the coccinellids Coccinella septempunctata L. and Adalia bipunctata L., and coccinellid and chrysopid larvae. An efficacy index developed to assess the effectiveness of foliage-inhabiting predators indicated that those with the greatest potential were Chrysopa larvae and adult C. septempunctata in 1987, and adult C. septempunctata and C. verbasci in 1988. The earwig, Forficula auricularia L., showed potential as a predator of A. pomi in 1989. Of the epigeal arthropods tested, the carabids Amara aenea DeGeer, Bembidion quadrimaculatum oppositum L., and Harpalus aeneus F., and the ants Formica fusca group, Myrmica ameryana Forel, and M. monticola Wheeler were the most active feeders on A. pomi.