Female southern pine beetles, Dendroctonus frontalis Zimmermann, may propagate two species of symbiotic fungi in a prothoracic mycangium. Females can carry either Ceratocystiopsis ranaculosus Bridges and Perry or an unnamed basidiomycete or both; some carry no fungi. Thus, females can be categorized into one of four groups based on mycangial content. We examined size and lipid content of emerging brood adult females based on these mycangial fungal classes. Female beetles carrying the basidiomycete, either alone or in combination with C. ranaculosus, were larger, heavier, and contained more lipid than did females carrying only C. ranaculosus. Size and lipid content also varied by season, as did the number of females carrying different fungal combinations. Regression analysis showed that variation in the occurrence of the basidiomycete was significantly related to variation in averages of beetle size and lipid content measurements.

The aphid fauna of “Las Cañadas del Teide” (Tenerife Island) at present is made up of 11 species including the only species endemic to Macaronesia. This new species of the genus Acyrthosiphon is described and compared with other species of this genus; A. supranubius sp.nov. lives on the endemic Spartocytisus supranubius (Leguminosae).

Adults of Choristoneura fumiferana, C. biennis, and an unidentified species reared from larvae or caught in pheromone traps from British Columbia were used for isozyme analysis to confirm the species identity, and for morphological study to determine the percentage of individuals with spiculate aedeagi. About 82% of C. fumiferana and less than 3% of both C. biennis and C. unidentified species (CPG) have spicules on the left side of their aedeagi. The number of moths that need to be sampled to determine a species is presented, based on the presence or absence of spicules.

A large population of Peponapis pruinosa, a solitary, oligolectic, ground-nesting bee and important pollinator of cucurbits in the United States and Mexico, was studied foraging on pumpkin (Cucurbita pepo) at a site in Cambridge, Ontario, from 23 July to 30 August 1990. We measured the diurnal and seasonal foraging trends for P. pruinosa and compared our findings with those for P. pruinosa elsewhere. The females are active on flowers in the mornings from dawn on. The males are active later in the mornings and spend afternoons and nights in closed flowers. The seasonal emergence of the bees closely parallels that of the plants’ anthesis. Diurnal activity is related to the availability of pollen resources on the flowers of C. pepo. Almost all pollen is removed from the synandria within 2 h of the start of foraging by female bees. Ambient temperature threshold for foraging by both sexes is about 10 °C.

The endemic Galápagos’ genus Neoryctes Arrow has had a confused nomenclatorial and taxonomic history. Evaluation of morphological variation in the 41 specimens now available confirms the distinctiveness of the genus and establishes the existence of four species, each restricted to a single island. The original Darwin specimen, named Oryctes galapagoensis by G.R. Waterhouse in 1845, is shown to be from Isla Santiago. Two other names are valid: N. linelli Mutchler for the population on San Cristobal and N. moreti Dechambre for the one on Santa Cruz. The population on Floreana is named as a new species, N. williamsi. Neoryctes most likely originated from a Pentodontini dynastine ancestor from lowland South or Central America. The ancestor first dispersed to Isla San Cristobal, one of the oldest islands. It is hypothesized that before hindwing reduction occurred, which is now characteristic of all members of the genus, individuals from San Cristobal spread to the other islands. Subsequently, possibly during periods of Pleistocene aridity, each population became restricted to its present range in the moist highland zone of an individual island.

Field plot tests during two seasons show that augmentative releases of Perillus bioculatus can control first-generation eggs and larvae of the Colorado potato beetle (CPB) under Quebec short-season conditions. Stinkbugs mass-reared on CPB were introduced manually as 2nd- and 3rd-stage nymphs during spring oviposition of the beetle at densities of one nymph per 50–225 CPB eggs recruited per plant, in 0.025-ha plots. Sampling at intervals of 1–3 days measured predator establishment, CPB egg and larval mortality, and foliage protection level. Direct observations were used to document predator-prey relationships and to determine weather conditions favourable to P. bioculatus.

In the 1 st-year test, with predators released over all plants within plots, CPB control was compared among: (1) stinkbugs alone, (2) the bioinsecticide Bacillus thuringiensis (BT) as Trident™, (3) a combination of both control alternatives, and (4) no protection against the CPB. BT and stinkbugs, both alone and in combination, produced significant control as measured by percentage reductions in prepupal drop to the ground, new adult emergence, and foliage protection. Only treatments involving P. bioculatus reduced CPB egg eclosion which was the key control factor; it is strongly correlated with overall control level.

In the 2nd-year test, predators were released in a central area comprising only 25% of all plants within plots. Predator and CPB egg mass densities were manipulated to produce predator: prey ratios of 0:1, 0:2, 1.5:2, 1.5:1, 3:2, and 3:1, representing average ratios of 0, 1.5,or 3 P. bioculatus per plant, and 1 or 2 CPB egg masses per plant at release time. As expected, central release produced complex interactions between control, and predator and prey densities. High beetle density slowed predator emigration from the centre, more so at low predator density than at high predator density. Predators moved more quickly within the same row than across rows. CPB eggs were destroyed in large numbers in both years but in 1993, final control correlated with larval rather than egg predation. A maximum 80% reduction in prepupal drop to the ground was obtained at the 3:1 predator:prey ratio (1 P. bioculatus:95 CPB eggs recruited per plant).

The results prove the efficacy of P. bioculatus for biological control of first-generation L. decemlineata populations, at densities resulting in approximately 300 eggs laid per plant during spring oviposition in the study area. Despite low natural populations of P. bioculatus and unclear prospects for commercial availability at reasonable cost, it is evident that stinkbug releases have potential as a non-chemical control measure within an IPM program in Quebec potato production.

The potato aphid, Macrosiphum euphorbiae (Thomas), infests oilseed flax, Linum usitatissimum L., when the crop is flowering and developing seeds. Field studies in cages, open plots, and commercial fields showed that the aphid can cause yield losses of 20% or more, but reduces the weight of individual seeds only slightly and has no effect on oil quality. A single application of a foliar insecticide at full bloom or the green boll stage will control the potato aphid until harvest. The yield loss of flax is 0.021 t/ha per aphid per plant for crops sampled at full bloom and 0.008 t/ha per aphid per plant for crops sampled at the green boll stage. The economic threshold for the potato aphid in flax is three aphids per plant at full bloom and eight aphids per plant at the green boll stage, based on crop prices and control costs from 1990 to 1992. Aphids should be controlled as soon as the economic threshold is exceeded. If control is not warranted at full bloom, aphid densities should be assessed again at the green boll stage. The effective use of growth-stage-specific sampling and economic thresholds will maximize the benefits of insecticide use for producers and minimize unnecessary or ineffectively timed applications.

New information concerning Palaearctic species of Spalangiopelta is provided. Two new species are described and illustrated: S. alboaculeatasp. nov. (type locality: England, Cambridgeshire, Santon Downham) and S. hikosp. nov. (type locality: Japan, Kyushu, Mt. Hiko). Additional information and illustrations are provided for S. procera; the male is described and illustrated for the first time, and notes and photomicrographs of the forewing and antenna are used to augment the previous descriptions of the female. The male of S. dudichi is also described and illustrated for the first time. Notes are provided to accommodate these new species and males in the key to world species of Spalangiopelta (Darling 1991) and the phylogenetic and biogeographic implications are discussed.

The spatial distribution of the eulophid Sympiesis marylandensis Girault was examined in Connecticut in October 1988 and 1989 by vacuum-sampling apple trees in three zones of two apple orchards infested by its gracillariid host, the apple blotch leafminer, Phyllonorycter crataegella (Clemens). The abundance of females of S. marylandensis decreased with increasing distance of the zone or the sampled apple tree from the forest. The abundance of males in different regions of the orchard was similar. In two of three samples, the density of mines of leafminers was significantly higher near the edge than in the center of orchards. Parasitization of leafminers of the second generation and the number of female parasitoids vacuum-sampled during the third generation did not have a similar distributional pattern. We suggest that the amount of parasitism by S. marylandensis would be affected negatively by spraying trees at the border of orchards to kill immigrating pests.

The role of adult nutrition in longevity, progeny production, and offspring sex ratio of Trichogramma minutum Riley was examined. On average, honey-fed females lived 26.4 days and produced 260 offspring; unfed females lived 3.5 days and produced 80 offspring. Feeding on fructose or sucrose also significantly increased longevity and fecundity over unfed females (fructose, 23 days and 230 offspring; sucrose, 21 days and 230 offspring) but to a lesser degree than feeding on pure honey. Females fed yeast suspension or water had no significant increases in longevity or fecundity compared to unfed females. Offspring sex ratios of long-lived females were male-biased (50–62% males), those of short-lived females were female-biased (74–82% females). Lifetime reproduction of honey-fed females was highest at 20–25 °C and relative humidities of 20–80%, but short-term offspring production (during the first 2 days after emergence) was highest at 30 °C and 60–80% RH. Females that had access to honey for only a 24-h period did not increase their offspring production over the first 4 days of their lives when compared to unfed females. The potential benefits of feeding adult T. minutum for mass-rearing and field release are discussed.

The population dynamics of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae), were documented on potatoes grown in Prince Edward Island (P.E.I.) from 1990 to 1992. By comparing degree-day accumulations above 10°C, both first occurrence and peak flights of male adults occurred earlier than elsewhere in North America. Because potatoes in P.E.I. are attacked earlier and over a longer period of time than potatoes grown in other regions, the insect is an important pest of potatoes in P.E.I. The correlation between peak numbers of male adults caught in pheromone traps and egg masses on potato plants was not significant (p = 0.22). However, the correlation between egg masses per potato stalk and larvae per potato stalk was significant (p = 0.003). Trapping adults and monitoring potato plants for the presence of egg masses during the period from 250 to 500 degree-days appears to be a reliable way to determine the presence of adults and the potential impact of larvae on yield of potatoes.

Egg-laying data are available for laboratory colonies of Lygus lineolaris (Palisot de Beauvois) (Bariola 1969; Khattat and Stewart 1977; Fleischer and Gaylor 1988), but there is no information on egg-laying for females from field populations in Canada. This paper presents egg-laying data for field-collected, overwintered and first-generation females of L. lineolaris from southern Manitoba in 1990 through 1992.

De Clercq and Degheele (1990, 1992) described the morphology and bionomics of a predatory stink bug under the name of Podisus sagitta (Fabricius). The studies were based on a culture started from specimens originating from Surinam. Workers from the Agricultural University of Wageningen, The Netherlands, who provided us with the specimens, referred to the species by the name “Podisus sagittus (L.)”(Adidharma 1986), which we corrected to P. sagitta (Fabricius), the name mentioned by Van Duzee (1916). Subsequent to our studies, Thomas (1992) published an illustrated key to the New World species belonging to the pentatomid subfamily Asopinae, which, for the first time, enabled accurate identification of species.

The lodgepole terminal weevil, Pissodes terminalis Hopping, is the only member of its genus that consistently oviposits in the expanding terminal shoots of its hosts (Stark and Wood 1964). The white pine weevil, Pissodes strobi (Peck), oviposits in the year old shoot of spruce and pine (Wallace and Sullivan 1985) and other Pissodes species have their oviposition sites on boles, root collars, and slash (Furniss and Carolin 1977). In southern British Columbia, P. terminalis is primarily univoltine although adults may live and oviposit for 2 or more years. Although its life cycle is closely synchronized with terminal phenology, its life history is extremely variable (Cameron and Stark 1989). Adults are active in late spring to early summer, when they can be found feeding on the tissues of the developing terminal shoot and foliage. Soon after this maturation feeding, mating occurs, and oviposition punctures are excavated in the bark of the new terminal. Usually a single egg is deposited into each puncture (Drouin et al. 1963; Stark and Wood 1964; Maclauchlan 1992).

In recent years, the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), has become a major pest of raspberries in the Fraser Valley, British Columbia (Anonymous 1994). Overwintering C. rosaceana larvae begin feeding on raspberry leaf buds in early April. Heavy infestation causes serious damage to raspberry plants. Larvae of the first generation hatch in late June to early July, and feed on growth terminals and berries. The occurrence of this generation usually coincides with berry harvesting time. Because the larvae are shaken from the plants by the harvesting machine, C. rosaceana can be a major contaminant of machine-harvested berries.

Subsocial behaviour, defined as postovipositional parental behaviour that promotes the survival, growth, and development of offspring, has been reported in diverse orders in insects (Tallamy and Wood 1986). Especially in the order Coleoptera, more that 10 families include subsocial species (Hinton 1981; Brandmayr 1992). For chrysomelid beetles, with the exception of members belonging to the subfamily Cassidinae, such behaviour has been known previously in a few species (Windsor and Choe 1994).