Field experiments demonstrated that the western balsam bark beetle, Dryocoetes confusus, responded best to multiple-funnel traps baited with mixtures of (+)- and (−)-exo-brevicomin. (±)-exo-Brevicomin released at 0.8 mg per 24 h performed as well as or better than release rates of from 0.2 to 1.0 mg per 24 h in terms of the number of baited trees which were mass attacked (80%), average attack density, and average number of trees attacked within a 10-m radius of baited trees. Baiting more than one tree in a spot resulted in an intensification of attack on baited trees and increased the number of trees attacked within 10 m of each spot.

The seasonal occurrence of four species of egg parasitoids of the tarnished plant bug (Lygus lineolaris) was determined in three different habitais: fields of mixed weeds. alfalfa (Medicago sativa L.). and crown vetch (Coronilla varia L.) in southwestern Quebec in 1991 and 1992. Parasitoids studied were the mymarids Anaphes iole Girault, Polynema pratensiphagum (Walley), and Erythmelus miridiphagus Dozier and a scelionid, Telenomus sp. Adult populations of these parasitoids showed three or four population peaks in all habitats throughout the season. Adult parasitoid activity started during the first egg-laying period of L. lineolaris at a temperature accumulation of 73 degree-days (DD). The overwintering period began in mid-October at 1277 and 1058 DD for 1991 and 1992, respectively. All the parasitoids had a strong synchrony with L. lineolaris populations; specifically, marked peaks in the adult population of all species were in synchrony with the egg-laying periods of L. lineolaris.

A 3-year survey of apple and cherry orchards in the interior of British Columbia revealed that speckled green fruitworm, Orthosia hibisci, is the dominant fruitworm species in the south of the Okanagan Valley. Larvae of speckled green fruitworm collected from orchards that used no or minimal insecticides experienced 22.5–29.0% parasitism in 1988–1990. Earinus limitarus was responsible for 98.9% of the parasitism in the 3 years. Parasitoids of minor significance included a Meteorus sp. (Hymenoptera: Braconidae) and Compsilura concinnata (Mg.) (Diptera: Tachinidae). Data from laboratory trials indicated that feeding by O. hibisci in the fifth and sixth instars was significantly (P < 0.05) reduced when larvae were parasitized by E. limitarus. Orthosia hibisci in the second through sixth instars in sleeve cages damaged developing apples in the field. Earinus limitarus appears able to reduce O. hibisci numbers for the following year as well as immediate host feeding damage in at least the last two instars.

Feeding rates of Colorado potato beetle larvae were measured in 24-h trials in small field cases on potato leaflets that remained attached to the plants. Four models were constructed to explain the results; these differed by including or excluding the effect of insolative heating on larval body temperature, and by including or excluding thermoregulatory behavior, in all combinations. In all instars, observed feeding was independent of mean body temperature during the trial as estimated by each model, and less than the amount predicted using this mean to drive constant-temperature feeding rate functions.

The four models were assessed by regressing model predictions on observed feeding rates. For first and second instars, there was no relationship between observed feeding and the amount predicted by any of the models, probably because the feeding rate was small relative to the precision of the measurements. For third and fourth instars, predictions from the model that included both insolative heating and behavioral thermoregulation did not differ significantly from observations. Simulations using this model suggested that daily mean body temperature fails to predict foliage consumption because this mean cannot account for the effects of transient occurrences of suboptimal temperatures.

Sex pheromone-mediated mating disruption using Isomate-C® pheromone dispensers was evaluated as a means of controlling the codling moth, Cydia pomonella, over three consecutive growing seasons in organically managed blocks of apples at two commercial apple orchards in Ontario. The objective of the study was to determine if mating disruption could be used to stabilize or reduce the amount of damage caused by indigenous codling moth populations. The emission rate of the pheromone dispensers was estimated using volumetric and gravimetric methods. Efficacy of the pheromone treatment was assessed by comparing pheromone-baited trap catches of adult male codling moths in pheromone- and insecticide-treated blocks of apples, and by estimating damage caused by first- and second-generation codling moths in pheromone- and insecticide-treated blocks as well as in small plots of apples where the codling moth was not controlled. The estimated average release rate of pheromone varied from 22.2 to 30.3 mg per ha per h. The seasonal total number of adult male moths trapped in the pheromone-treated blocks was from 3.8 to 25.3% of the number trapped in insecticide-treated blocks; during one season at one farm, no moths were trapped in a pheromone-treated block. Treatment with pheromone did not prevent an increase in codling moth damage. At one farm, damage increased ca. 5-fold during the 3-year study. At the other farm, damage increased ca. 4-fold during two consecutive growing seasons in one block and ca. 4-fold during three consecutive seasons in the other block. At both farms there was a marked increase in the amount of damage between the first and second generations of the pest. Possible reasons for the failure of the pheromone treatment to prevent increases in codling moth damage are discussed.

Triarthria setipennis is a tachinid parasitoid of the European earwig (Forficula auricularia) and following introduction from Europe has become established in British Columbia and Newfoundland, where it provides low levels of control. Populations of T. setipennis were surveyed in central Europe during 1989–1991 and individual insects reared to identify available biotypes that may be more effective than biotypes already established in Canada. Additional information is provided on parasitoid biology; this could facilitate new introduction of T. setipennis which could be used to augment existing or introduced populations in Canada for the control of F. auricularia. Microclimatic conditions and sufficient territory space for pairs are important to elicit mating activity. Older males mated readily with newly emerged females. The gestation period of mated females is on average 19 days. Triarthria setipennis is ovolarviparous and lays its eggs close to potential hosts. Chemicals are involved in the host-finding and host-acceptance response of the females. Females lay on average 235 eggs. The oviposition period lasts 4–5 days. Once a first-instar larva contacted a host, it mounted it and tried to penetrate through the intersegmental skin between the head and thorax, or on the thorax or abdomen; this process takes less than 3 min. Only 16.7% of the parasitoids manage to penetrate the host successfully. The duration of larval development is variable, taking from 2 weeks to 2 months during June and July. Most pupae were obtained during August. Overwintering occurs in the pupal stage. In Germany and in the northwestern part of Switzerland there is one full and a partial second generation per year. The first generation of T. setipennis in southern Austria shows a long emergence period and the individuals differ markedly in colour. The highest rate of parasitism in the field was 46.9%.

This study describes an image analysis method that reliably quantifies feeding damage by leaf beetle larvae (Altica spp.) to Canada thistle leaf disks. Quantification is objective, uncomplicated, precise, rapid, and usable with any image analyzer. Image analysis of dried, pressed leaf disks is not recommended, as the amount of shrinkage of the eaten area upon drying varies with the amount eaten. Analysis of fresh material is advised. Image analysis of fresh leaf disks will be a useful method of comparing rates of consumption of two Altica species, one of which is being considered as a new candidate for the biocontrol of Canada thistle, and also other insects with similar feeding habits.

Eggs of Ephoron album and E. shigae were studied by scanning electron microscopy. They showed similar structure of both polar cap and micropyles, but had different chorionic patterns. Micropyles were of the tagenoform type and, whereas in most mayflies thev are equatorial or subequatorial, in these eggs they were located close to the apical pole. The chorion was smooth in E. album and had a large mesh reticulation in E. shigae. The effect of water in causing the cap to swell and expand was tested by fixing eggs of E. album at different lime intervals after their mechanical deposition in water. The polar cap was a composite apparatus, consisting of finger-like projections with slight terminal enlargements, which arose from a common hood. The latter was connected via a thread bundle to the chorionic surface. In turn, the thread bundle arose from a chorionic collar located immediately underneath the hood. Each finger-like projection was composed of a large number of thin threads packed together, each ending in a small terminal knob. The function of the polar cap was discussed in relation to egg–water interaction.

Puparia of Delia radicum collected in late autumn at Winnipeg and Portage la Prairie (Manitoba), St-Jean-sur-Richelieu (Quebec), London (Ontario), and St. John’s (Newfoundland) were parasitized mainly by Aleochara bilineata (Gyllenhal) (Coleoptera: Staphylinidae) and Trybliographa rapae (Westwood) (Hymenoptera: Cynipidae). At Winnipeg, St-Jean, and St. John’s parasitism by A. bilineata was high (<94%) and by T. rapae was low (<3%). At London, both parasitoids attacked less than 14% of the host puparia. At Winnipeg, host population density was related to parasitism by A. bilineata and to the temperature and rainfall during June and July. Parasitism by A. bilineata may be related to cumulative degree-days over 5°C during June and July at Winnipeg and during June and September at London. In Canada, the parasitoid complex is not effectively stabilizing host population density. The introduction of additional parasitoid species should be considered.

The seasonal occurrence and number of generations of Lygus lineolaris (Palisot de Beauvois) were studied on alfalfa (Medicago sativa L.), everbearing strawberries (Fragaria × ananassa Duchesne), oilseed rape (Brassica napus L.), and stinkweed (Thlaspi arvense L.) in field plots at Winnipeg, Manitoba, and in commercial alfalfa and oilseed rape fields throughout the agricultural areas of Manitoba in 1990–1993. Lygus borealis (Kelton) was studied only during 1993. Lygus lineolaris had two non-overlapping generations in southern Manitoba. Overwintered adults migrated onto host plants during die first 3 weeks of May, and females containing chorionated eggs were found in relatively small numbers for 5–6 weeks until the last 3 weeks of June. First-generation nymphs were present from the last half of May until the last half of July. During the last 2 weeks of June, the overwintered adults disappeared suddenly and were replaced completely by first-generation adults. First-generation adults eclosed during the last 2 weeks of June and in July, and first-generation females containing chorionated eggs were present for about 6–7 weeks until mid-August. Second-generation nymphs first appeared in late July or early August and most completed development by the end of September. Second-generation adults were found from the first half of August until they hibernated in October and November. Most second-generation females contained previtellogenic eggs and. therefore, were in reproductive diapause. In 3 of the 4 years, the overwintered adults appeared to include all second-generation adults plus 0–20% of the first-generation adults. The data from commercial alfalfa and oilseed rape fields indicated that the seasonal occurrence of L. lineolaris was relatively uniform in most or all agricultural areas of Manitoba. Lygus lineolaris has one generation (the second generation) on oilseed rape, and the eclosion and dispersal of reproductively active first-generation adults were well synchronized with the bud and flower stages of this host plant in southern Manitoba. In 1993, L. borealis had two generations and its seasonal occurrence was similar to that of L. lineolaris.

The control of the red sunflower seed weevil, Smicronyx fulvus LeConte, relies on the use of insecticides. An economic injury level is essential to the judicious deployment of insecticidal control. Field studies were conducted in 1992 and 1993 to quantify the weight loss and oil content loss of damaged kernels as a result of larval infestation and the relationship between the adult weevil population and the subsequent number of damaged achenes. We found that for each weevil sampled in plant stages R5.0–5.3, 26.88 damaged achenes resulted. Damaged kernels lost an average of 9.86 ± 2.36 mg (mean ± SD) per kernel, approximately equal to the amount consumed by a single larva. The oil content loss in damaged kernels was 3.34%. Economic injury levels were calculated as a function of the cost of controls, the market value, and the plant population density. Use of adult weevil counts when most plants in the fields are in plant stages R5.0–5.3 are recommended for calculating economic status.

Forest ants in Connecticut, especially Formica neogagates Emery and F. subsericea Say (Hymenoptera: Formicidae), feed on first- to third-instar larvae of gypsy moths, Lymantria dispar L. (Lepidoptera: Lymantriidae), but mainly forage on the ground while most young caterpillars are in trees. It would be helpful to obtain information about the individual ants that do climb trees. Thus, numbers of ants climbing up and down different species of forest trees were determined. Numbers varied with both tree species and trunk diameter. Some oaks, plus hickories, tended to have the most ant traffic. These trees were also the most likely to have trunk diameters positively correlated with ant activity. Ants appeared to obtain honeydew or perhaps nectar from the trees, as the crop contents of some ants tested positive for sugar. A possible way to induce more ants to climb trees, and thus to attack caterpillars in trees more frequently, would be to increase numbers of honeydew-producing insects in trees. It should also be possible to encourage ants by spraying trees with sugar solutions or other materials.

The daily pattern of oviposition, the rank order of oviposition preference for three potential hosts, and the effect of experience on oviposition preference were investigated under natural abiotic conditions in the obliquebanded leafroller, Choristoneura rosaceana. Females from the two adult cohorts occurring seasonally oviposited between 0400 and 2400 hours, with peak oviposition around 2000 hours. Both non-choice and choice oviposition trials revealed that the apple and snowberry hosts were preferred over wild rose. Oviposition preference resulted in delays in laying on the less preferred host, but seemed to have no effect on clutch size. Females caged with exclusive access to one of the three hosts appeared to have similar lifetime fecundity or longevity. A first oviposition on wild rose resulted in a delay in laying a second clutch on that host, which suggests the presence of aversive learning that could function to reduce the liklihood of laying successive clutches on a less preferred host. A first oviposition on the apple host, however, seemed to have no effect on further oviposition preference. Hence, it appears that learning would not function specifically to concentrate foraging of the females within apple orchards.

Trachycrusus, gen.nov., and two included species, lescheni sp.nov. and striatulus sp.nov., are described and figured from eastern Peru. Morphologically the genus bridges the gap between the highly modified ceratocanthine genera such as Scarabatermes Howden and the more typical genera such as Astaenomoechus Martínez and Pereira.

Field and laboratory studies were undertaken in southern Ontario to gain bionomical information on the adult strawberry root weevil (Otiorhynchus ovatus), a pest of ornamental conifer trees in nurseries. Emergence of overwintering adults began on 3 June 1991 and lasted 56 days, with 50% emerging within 18 days. Adults dispersed less than 5 m in 48 days from a single release point. About 50% of females were fecund. The laboratory temperatures at which adults were reared (15, 20, and 25°C) had no significant effect on fecundity (62.3 eggs per female) but influenced longevity; adults at 15°C lived longer than at 20 or 25°C. The mean preovipositional and ovipositional periods were 31.5 and 49.0 days, respectively. Less than 1% of adult weevils released in the field survived the winter; overwintering adults lived 10 months. Egg eclosion occurred 16 days after oviposition with 78% of the eggs viable. The significance of these biological observations in the development of management strategies for this pest is discussed.

Conophthorus Hopkins 1915 cone beetles are among the most damaging pests of pine (Pinus spp.) seed production in North America (Hedlin et al. 1980; Cibrián-Tovar et al. 1986). Current work on cone beetle molecular identification and semiochemicals requires a rapid and reliable method for sexing adult beetles. Head microsculpturation (Schwarz 1895; Wood 1982), overall beetle length, head width, and internal genital structures (or parts of them) visible when extruded through the genital opening (Lyons 1956) have been suggested as characters to sex adult Conophthorus. Herdy (1959) pointed out that abdominal tergite morphology could be used to distinguish males from females. The latter seems to be the most reliable, non-destructive way to sex Conophthorus specimens. Published illustrations (Kinzer and Ridgill 1972) have been found difficult to interpret by many researchers. To increase the reliability in sexing adult Conophthorus beetles, we prepared scanning electron micrographs (SEMs) of the terminal abdominal tergites of adult males and females, which we present here, clearly showing the diagnostic features of each sex.

In a study on the population dynamics of the predators of insect pests in apple orchards of Quebec, three specimens of the Asian coccinellid Harmonia axyridis were found. This is the first occurrence of this species in Canada