Based on synapomorphic character states in the parastigmal area of the fore wing, the genus Mesocoelus is transferred from the Orgilinae to the Agathidinae. Placement in the Orgilinae is rejected because of the presence of these synapomorphies and the absence of a subapical notch on the ovipositor, a derived character state found in all known members of the Orgilinae.

Two hundred and nineteen primary types of Aculeata housed in the Canadian National Collection were examined and listed. These were contributed by the following authors: Olmi (56), Evans (31), Viereck (27), Allen (23), Cockerell (21), van Lith (10), Sladen (10), Timberlake (6), Mickel (5), Carter (4), Provancher (4), Williams (3), Francoeur (2), Michener (2), Townes (2), Atwood (1), Bequaert (1), Bohart (1), Finnamore (1), Huber (1), Krombein (1), Laberge and Bouseman (1), Mitchell (1), Ponomarenko (1), Sandhouse (1), Say (1), Shanks (1), and Siri and Bohart (1).

The temporal aspects of the effect of feeding damage to canola seedlings by adult flea beetles on yield were determined by protecting plants in 0.836-m2 field plots from beetle attack with screen cages for varying periods. Yield was reduced most when plants were damaged during stages 1.0–2.2, 5–10 days after germination, but was not reduced when they were damaged after reaching stages 2.3–2.4, 20 days after germination. Plots exposed to attack for periods greater than 5 days before protection had smaller yields and fewer plants than plots protected from the time of germination for 5 or more days before exposure to flea beetle attack. Yield losses caused by larvae were measured by growing plants inside field cages to stage 2.3–2.4 before exposing them to feral adults to establish larval populations; yields of plots treated subsequently with drenches of carbofuran to kill larvae were then compared with yields of untreated plots. A yield loss of 5% was observed at larval densities of 0.16/cm2, estimated from soil core samples and captures of adults in emergence cages. The results confirm that continuous protection of canola during and after germination is superior to post-germination protection and suggest that activities of flea beetle larvae reduce yield.

Individual growth rates of larval dragonflies can exhibit density dependence under field conditions. Retarded growth can occur despite an apparent abundance of food and may be due to some form of stress caused by aggressive interactions. I used laboratory experiments to test for effects of larval density, accumulated waste products, and disturbance on growth of larval Enallagma ebrium given abundant food. Experimental treatments had no clear effect on larval weight, size, or duration in an instar. Thus aggressive interactions, in the absence of food limitation, may not be important in affecting growth rates of larval odonates.

Three species of egg–larval parasites in the genus Chelonus (Hymenoptera: Braconidae) exhibited host-searching behavior when exposed to body scales from 6 species of Lepidoptera representing 3 families. The nonspecific response to scales from several hosts appears to be of adaptive value to Chelonus spp., as it is consistent with the polyphagous habits reported for this genus. The searching response was more widespread and intense in an Ethiopian Chelonus sp. than in 2 other species. It is thought that the broad responsiveness to host scales may detrimentally affect parasite searching ability through excessive loss of searching time, although sensory adaptation to the kairomones might serve to attenuate such effect. Some coevolutionary aspects of this host–parasite chemical interaction are discussed.

A study was conducted to quantify the relationship between ambient air temperatures and adult internal body temperatures of three rangeland grasshoppers near Three Forks, MT. Results show a strong non-linear relationship between air and body temperatures over the range of temperatures normally encountered during the adult stage (approximately 2–42°C). Observations and historical data indicate the considerable influence of behavioral modification that results in grasshoppers attempting to maintain an optimal temperature range that minimizes development time. Results should be of interest to insect ecologists and those studying grasshopper biology and population dynamics.

The relationship between the phenological development of the spruce budmoth (SBM), Zeiraphera canadensis, and that of its primary host, white spruce, was studied in New Brunswick using descriptive indices for both insect and host development. Larval emergence of SBM was synchronized with bud burst of white spruce, the species on which most eggs are laid. Subsequent SBM larval development can be estimated through reference to the development index for white spruce. For black, Norway, and red spruce, initial bud burst occurred approximately 15, 3, and 15 days, respectively, later than white spruce and this asynchrony is probably one of the reasons why the SBM is not an important pest on these tree species.

Seasonal history, adult flight activity, and damage of the obliquebanded leafroller, Choristoneura rosaceana (Harris), on filbert were studied during a 7-year period between 1976 and 1984. Data from periodic field counts and moth catches in sex-attractant traps indicated two generations per year. The first-generation adult capture peak was generally higher than the second, except in 1978 when about an equal number of moths were trapped from both generations. A physiological time scale, using degree-days (DD), was devised for predicting emergence of obliquebanded leafroller adults. The first adults from overwintering larvae emerged at approximately 374 DD above a threshold of 10 °C starting 1 March. A total of 1172 DD were required between the first and the last adult emergence during the first generation and about 519 DD during the second generation. The obliquebanded leafroller causes both foliar and nut damage in filbert orchards of Oregon. Foliar damage was insignificant, but nut damage, caused exclusively by the first-generation larvae during June and early July, was highly destructive. Larval feeding on nuts caused staining and premature drop of infested nuts resulting in substantial yield reduction in heavily infested orchards.

Mountain pine beetle (Dendroctonus ponderosae Hopkins) population dynamics, as well as potential for outbreaks and resulting tree mortality, are related in part to habitat temperature. As a first step in development of a life-stage, event-oriented simulation model, we have modeled the temperature-dependent development of the egg stage. The completed model includes a full description of variation in developmental rates and is capable of predicting duration and eclosion patterns for any temperature regime. This model was parameterized using data obtained from constant-temperature experiments at temperatures of 8, 10, 12.5, 15, 20, 25, and 30°C. Validation experiments were conducted for constant temperatures of 15, 17.5, 22.5, and 27.5°C and for variable-temperature regimes of 15±5 and 15±10°C. Validation results indicated that the model is capable of accurately describing the emergence curve for constant temperatures below 27.5°C. The model also faithfully represents emergence under variable temperatures of 15 ± 10°C. Potential reasons for lack of model fidelity in describing emergence at constant high temperatures and for 15 ± 5°C are discussed in the text.

The 1st-instar larva of Metrius contractus Eschscholtz is described and illustrated. The larva differs from those of other Carabidae (except some species of ozaenines) by having the epipleurites of the 9th segment and the tergum of the 8th segment transformed into a plate and by having the urogomphi antler-like and located in a vertical plane. These character states support the hypothesis, based on published analysis of the adult structures, that the monogeneric tribe Metriini is closely related to the tribes Ozaenini and Paussini. The ranking of Metrius, Ozaenini, and Paussini is re-evaluated and it is proposed that these three groups be combined in one tribe, the Paussini (sensu novo). The tribe Paussini, thus constituted, is placed with the tribes Brachinini and Crepidogastrini in the subfamily Paussinae. The relationships of the subfamily are unclear, but it probably represents a primitive element of the Carabidae. Based on the available data on bionomics and larval morphology of paussines, it is suggested that larvae of Metrius live in rotten logs and depend for their survival on some kind of animal which they attract through a secretion released at the extremity of the abdomen. The kind of animal and the type of interaction between the animal and the Metrius larvae remain unknown.

Several insect growth regulators (IGRs) were tested against citrus thrips, Scirtothrips citri (Moulton), in Munger cells. In all larval tests, the IGRs worked by preventing the thrips from developing to the pupal or adult stages. After exposing adult females to IGR residues, numbers of emerging progeny were reduced, although these results did not always rank the IGRs in the same order as the larval tests. The most effective IGR tested was UC84572, followed by cyromazine. Avermectin B1, a streptomycete-derived lactone, did not show IGR activity but acted as an insecticide and controlled the thrips at a much lower percentage active ingredient.

The carrot weevil, Listronotus oregonensis (Le Conte), is an important pest of carrot and celery in eastern Canada (Stevenson 1985). In Quebec, it is univoltine and overwinters as adults (Boivin 1985). At present, the only way to control this pest is with chemical insecticides applied either as granules at seeding time to control the larvae or as foliar sprays to control the adults before they start to oviposit. If integrated pest management (IPM) programs are to be applied to crops attacked by the carrot weevil, additional control methods are needed.