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.

A simple, reliable feeding bioassay was developed for screening certain biorational insecticides with potential use against pine bark beetles. Adult Ips calligraphus and Dendroctonus frontalis were fed freeze-dried phloem fortified with Avermectin B1, Bacillus thuringiensis with known coleopteran activity, or a bacterial metabolite (R003). Avermectin B1 was toxic to adult I. calligraphus by 4 days at an LC50 of 0.36 μg AI/g of diet. R003 was active against both beetle species, yielding 85–100% mortality after 10 days exposure to a concentration of 360 μg/g of diet. No B. thuringiensis product was toxic at a discriminating concentration of 200 μg of spore/crystal preparation per gram of diet. Beetle mortality on untreated diet remained <10% over the 4–10 days duration of feeding trials. Unadulterated, lyophilized phloem diet did not spoil during bioassays, provided that tanned beetles were taken for bioassays before they emerged from their natal host bolts. Microbial products with scolytid activity, such as Avermectin B1 and R003, could have future value for limiting bark beetle infestations of individual trees or small stands in urban or ecologically sensitive forests. Innovative strategies for delivery would have to be developed, however, to circumvent the cryptic habits of these phloeophagous beetles.

Mixtures of chlorpyrifos and cypermethrin were tested against 1-day-old larvae of corn earworm, Helicoverpa zea (Boddie), and fall armyworm, Spodoptera frugiperda (J.E. Smith), to determine the type of joint action involved in insect mortality. Statistical analyses indicated that mixtures of both insecticides interacted additively in both species. Chlorpyrifos alone was not as effective against larvae of fall armyworm as it was against larvae of corn earworm. No apparent differences in toxicity between the two species were observed with cypermethrin.

The beetle fauna of conventional, organic, and abandoned apple orchards was monitored in the Annapolis Valley, Nova Scotia, between May and September 1991. Treatment in the three types of orchards differed with respect to weed control, disease control, fertilization, and general care. The most commonly captured beetles in all three types of orchards were carabids, in particular, Carabus nemoralis Müller, Carabus granulatus Linné, Harpalus rufipes (DeGeer), and Pterostichus coracinus (Newman). In general, abundance of predaceous beetles was highest in the conventional orchards and lowest in the abandoned orchards. Generic composition of predaceous beetles was similar among orchards, although the abandoned orchards were characterized by high proportions of the larger carabids, C. nemoralis and C. granulatus, whereas the organic and conventional orchards were dominated by the smaller carabids, H. rufipes and P. coracinus. Although there were no significant differences among orchard type in the total abundance of non-predaceous beetles, the abandoned orchards displayed the greatest diversity of non-predaceous beetles, with the lowest diversity found in the organic orchards.

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.

Cold treatment is used to control the rusty grain beetle (Cryptolestes ferrugineus) (Coleoptera: Cucujidae), the predominant insect pest of stored grain in Canada. However, because it is difficult to cool the grain enough to control C. ferrugineus quickly, we have examined ways to reduce the cold-tolerance of adult C. ferrugineus, the most cold-hardy stage. We compared the efficacy of two ice nucleators, Pseudomonas syringae and Fusarium avenaceum, to decrease cold-tolerance of this insect, as well as their thermal stability. Ice nuclei from the bacteria P. syringae raised C. ferrugineus supercooling point from −17 to −6 °C, and increased mortality at −9°C for 24 h from 11 to 100%. Pseudomonas syringae held at 30°C for 16 weeks showed only a slight decline in its ability to reduce C. ferrugineus cold-tolerance. The fungus F. avenaceum raised the supercooling point of C. ferrugineus from −17 to −9°C, but only increased the mortality at −9°C for 24 h from 10 to 33%. Wheat treated with F. avenaceum and held at 30°C for 4 weeks reduced the cold-hardiness of C. ferrugineus, but had no effect after 8 weeks at 30°C. One reason for the difference between the two nucleators is that P. syringae had approximately 1000 times more ice nuclei per gram than did F. avenaceum. These results suggest that P. syringae is stable enough to reduce C. ferrugineus cold-tolerance after several weeks on warm grain. We discuss possible ways to increase the ice-nucleating activity of F. avenaceum.

Many soil-inhabiting insects are susceptible to entomopathogenic nematodes but the degree of susceptibility ranges widely. Much is understood about the habitat of insect pests in relation to their susceptibility but little attention has been paid to the influence of physical deterrents. "Physical deterrents" is used here to include morphological barriers (passive deterrents) and behavioural responses to attack (active deterrents). The roles of both are reviewed and discussed, in particular with reference to wireworms (Elateridae), a group of insects generally resistant to the nematodes. Knowledge of insect morphology and behaviour as well as habitat is important in predicting susceptibility to entomopathogenic nematodes.

Traps consisting of open, cylindrical tins containing moistened clay aggregates were evaluated as field oviposition sites for corn rootworm, Diabrotica spp. Six trap features were investigated: clay aggregate size, water saturation level, trap opening, trap cover, trap volume, and trap position relative to corn plants. More eggs were recovered in traps containing clay aggregates ranging from 0.5 to 3.5 mm diameter compared with aggregates from 2.5 to 8.0 mm diameter. Saturation of the trap to 2.5 cm from the opening resulted in greater egg recovery compared with traps saturated to 6.0 cm from the opening. Covering the exposed surface of the trap with a metal ring and/or a corn leaf increased egg recovery in the field.

Oviposition traps were placed in four commercial corn fields in 1990 and three in 1991 to monitor egg populations. Egg recovery from traps and estimates of the absolute egg population in the soil were compared with densities of adult corn rootworm to predict larval damage on roots of corn planted the next year. In five fields, adult populations were above the current economic threshold of one beetle per plant. However, economic damage to roots occurred only in the field in which the most eggs were recovered from traps (226.6 eggs per trap) and soil samples (30.2 eggs per litre). Mean egg recovery per trap per field was correlated with mean damage ratings from untreated corn.

Deraeocoris sanghonami sp.nov. is described from Korea.

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%.

Sixteen genera are recognized in the Clinocerinae (Diptera: Empididae): Dipsomyia Bezzi, Proagomyia Collin, Asymphyloptera Collin, Proclinopyga Melander, Rhyacodromia Saigusa, Trichoclinocera Collin, Clinocera Meigen, Oreothalia Melander, Roederiodes Coquillett, Clinocerella Engel, new status, Hypenella Collin, Kowarzia Mik, Dolichocephala Macquart, Phaeobalia Mik, Bergenstammia Mik, and Wiedemannia Zetterstedt. The subgenera of Clinocera are no longer recognized and the genus is divided into six tentative informal species groups. The following new generic synonyms are proposed: Hydrodromia Macquart = Clinocera; Archiclinocera Frey and Hypoclinocera Frey = Kowarzia; Lamposoma Becker, Fur Garrett Jones, and Obstinocephala Garrett Jones = Dolichocephala. A key to genera is provided for the identification of adult specimens of Clinocerinae, all genera are described, several lectotypes are designated, and male and female terminalia are illustrated. A world list of species is included for each genus, identifying new combinations. Cladistic relationships of the genera of the Clinocerinae are presented.

Zanclotus Wilder is transferred from the Clinocerinae to the Oreogetoninae. Dryodromia Rondani, also formerly in Clinocerinae, is considered to be most closely related to Hesperempis Melander, both of which are hypothesized to share apomorphies with the Empidinae + Hemerodromiinae. The genera Boreodromia Coquillett, Ceratempis Melander, Ephydrempis Saigusa, Niphogenia Melander, Sabroskyella Wilder, and Trichopeza Rondani also are removed from the Clinocerinae and transferred to the subfamily Trichopezinae, new status. In addition, Apalocnemis Philippi, Gloma Meigen, Hyperperacera Collin (all formerly in Oreogetoninae) and Heleodromia Haliday (formerly in Hemerodromiinae) are transferred to the Trichopezinae. Heterophlebus Philippi (formerly in Oreogetoninae) and Rubistella Garrett Jones (formerly in Brachystomatinae) are removed from synonymy and also transferred to the Trichopezinae. This subfamily is described, and the phylogenetic relationships and.geographic distribution of the included genera are discussed. The Trichopezinae is considered most closely related to the Brachystomatinae (exclusive of Homalocnemis Philippi) and Ceratomerinae. These three subfamilies are hypothesized to represent the sister group to the Microphorinae + Dolichopodidae.

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.

Damage by Hylobius congener, the seedling debarking weevil, to newly planted conifer seedlings was reduced to tolerable levels by treating the roots of the seedlings with the nematode Steinernema carpocapsae (Weiser) before planting. A practical treatment method was to apply a suspension of infective juveniles (IJs) in water to seedlings in multipots with a watering can. An application rate of 300 000 IJs per seedling is recommended. The plantation should be at least 500 m from recent clearcuts and the entire plantation should be treated to avoid negation of treatment effects by invading uninfected weevils. It is suggested that a similar method may also be effective against other species of weevils that damage conifers near the soil surface.

The digestive proteinases of three important pests of canola, Brassica napus L. and B. rapa L., in western Canada were characterized by assessing the proteolytic activity of homogenates of their midguts against azocasein or azoalbumin at various pH levels and in the presence of diagnostic proteinase inhibitors. The midgut of larvae of the bertha armyworm, Mamestra configurata Wlk., had maximum proteolytic activity at pH 10.5 which was inhibited 45–60% by serine proteinase inhibitors such as the soybean trypsin inhibitor. The midgut of larvae of the diamondback moth, Plutella xylostella L., had maximum proteolytic activity at pH 10 which was inhibited 56–75% by serine proteinase inhibitors. The two lepidopterans thus use a serine-like proteinase in digestion. The midgut of adults of the flea beetle, Phyllotreta cruciferae Goeze, exhibited maximum proteolytic activity at pH 5 which was inhibited 33–61% by specific cysteine proteinase inhibitors such as cystatin and trans-epoxysuccinyl-L-leucylamido (4-guanidino)-butane (E-64) and was activated strongly by L-cysteine. Aspartic proteinase inhibitors such as pepstatin A also decreased proteolytic activity by 21–50%. Serine proteinase inhibitors were without effect. Therefore, P. cruciferae appears to use both cysteine- and aspartic-like proteinases in digestion. Cotyledons and first true leaves of canola, B. napus cv. Westar, contained inhibitory activity against serine, cysteine, and aspartic proteinases when tested against bovine trypsin, papain, or porcine pepsin, but the level of antiproteinase activity is insufficient to provide significant resistance against any of these pests.

The monoterpenes (±)-α-pinene, (1S)-(−)-β-pinene, (R)-(+)-limonene, and myrcene did not enhance the catch of red pine cone beetle, Conophthorus resinosae, in traps baited with the female sex pheromone, (±)-trans-pityol. Traps placed in the upper half of the tree’s crown caught significantly more beetles than those hung from the tree’s trunk 2 m above ground. No significant differences in trap catches were found among standard yellow Japanese beetle trap tops and those painted red, green, blue, white, black, or yellow.

Hylobius congener, the seedling debarking weevil, is a pest of newly planted coniferous seedlings in clearcut forest in the Maritime provinces (Magasi 1988). Adult weevils feed on the bark of the seedlings, which are often girdled and killed. Pendrel (1990, pers. comm.) investigated the insect's life history and behavior, and a number of cultural and chemical controls. He developed combinations of control methods to match the variety of site types and cultural practices found, but recognized a need for a method that would be suitable across a variety of conditions.

Protopiophila litigata sp.nov. is described from Ontario and Nova Scotia. McAlpine’s (1977) key to the species of Protopiophila is modified to facilitate identification of the new species. Behaviours of P. litigata and P. latipes were studied in Algonquin Park, Ontario. Whereas P. latipes reproduces on corpses in advanced stages of decay, P. litigata mates and oviposits on discarded cervid antlers, ignoring other carrion. Unlike P. latipes, males of P. litigata engage in ’mate guarding’. These traits probably represent autapomorphies of P. litigata.

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.

A new definition of the subgenera of Dercylus Castelnau, 1832, is proposed and their synonymy is clarified. Four subgenera are included: Dercylus s.str., Eurydercylus subgen.nov. (type species: Dercylus tenebricosus La Ferté-Sénectère, 1851), Asporina Castelnau, 1835, ma Licinodercylus Kuntzen, 1912. Dercylodes Chaudoir, 1883, and Pterodercylus Kuntzen, 1912, are considered junior synonyms of Dercylus s.str. Licinodercylus Kuntzen, 1912, replaces Physomerus Chaudoir, 1883, which is a junior homonym of three other generic names. The 14 known species of the subgenus Licinodercylus are then revised. Eleven of them are newly described: Dercylus (Licinodercylus) franiai Moret, D. onorei Moret, D. orbiculatus Moret, D. praepilatus Moret, D. screator Moret, D. davidsoni Moret, D. granifer Moret, D. nodosus Moret, D. gaujoni Moret, D. gibber Moret, and D. mathani Moret. The larva of Dercylus (Licinodercylus) orbiculatus sp.nov. is described, and the phylogenetic affinities of the tribe Dercylini are discussed. Finally, available ecological and biogeographical data are presented, with special regard to the Ecuadorian fauna, and hypotheses regarding their speciation modes are proposed.