As part of a detailed study of the life system of the alfalfa weevil, Hypera postica (Gyll.), in southern Ontario, two methods were developed for estimating numbers of eggs in the spring growth of alfalfa. The first is based on direct counts of the eggs, which are laid in clusters and hence, aggregated in distribution; for moderate levels of infestation (ca. 8 eggs per bouquet), estimates with acceptable precision may be obtained by taking a single 3-stem bouquet of alfalfa from 80 randomly selected ft2 (.09 m2) quadrats within a field. The second is based on counts of the oviposition punctures which are randomly dispersed and consistent with the Poisson distribution. Although slightly less accurate, this method will provide a valid index of the number of eggs with less labour; acceptable precision may be obtained by taking a single bouquet from just 32 quadrats.

Populations of leaf rollers on apple can be influenced by the proximity of alternative host plants, notably rose, privet, and antelope bush, in part because larval dispersal is common. Indications are that leaf roller population increases caused by parasite decreases are ultimate consequences of pesticide treatments, so that reductions in spray programs will not necessarily cause potential leaf roller pests to become actual pests. The composition of the leaf roller fauna on apple m the Okanagan Valley becomes increasingly complex as the environmental water balance is changed by cultivation and irrigation. There are indications that heavy vehicular traffic can be harmful to leaf rollers and their parasites nearby.

An absolute requirement for sugar could not be shown but laboratory rearing experiments using artificial diets have demonstrated a definite increase in weight of adult spruce budworm (Choristoneura fumiferana (Clem.) Freeman) with increasing dietary levels of certain sugars. Males exhibit a threshold of 0.9% soluble sugars above which higher sugar levels produce no further increases in size. Females respond with an increase in size up to 4.0%, the highest level tested. Generally, faster development rates accompany greater mature weights on diets with higher nutrient levels.

Maltose, raffinose, glucose, sorbitol, sucrose, and fructose are all good sugar sources. Galactose and trehalose are only slightly inferior. Lactose, ribose, melibiose, xylose, mannose, arabinose, and melezitose in the diet are little different from the sugarless control. Sorbose is somewhat inhibitory.

Results of transfer experiments confirm the importance of sugar particularly during late larval development. They also indicate that a high protein diet during early instars has a significant effect on development rates. These results suggest that departure from the normal synchrony of development in the insect and its host can affect both rate of development and mature size of the insect.

Lestes congener Hagen overwinters in the egg stage. There is a diapause just before blastokinesis, during which the egg is extremely resistant to low temperatures and desiccation. Post-diapause embryonic development can occur near 0 °C but will not take place until the eggs are wetted as the pond habitat fills in the spring. Hatching does not occur until the temperature exceeds about 5 °C and is highly synchronous. Larval development is rapid and is completed in the field in about 50 days. Emergence of the adults also is synchronous. Sexual maturation requires 3 weeks. Oviposition occurs immediately after copulation while the pair are still in tandem. It takes place only in dry stems of Scirpus. Adaptations of L. congener for life under rigorous prairie conditions are discussed.

Seven species originally described in the genus Lygus Hahn are here removed from that genus. The new combinations are: Lygus fortinensis Distant is transferred to Ellenia Reuter, Lygus hospitus Distant and Lygus pellitus Distant are transferred to Dagbertus Distant, Lygus lanuginosus Distant is transferred to Polymerus Hahn, Lygus vicarius Reuter is transferred to Proba Distant, Lygus repletus Heidemann is transferred to Dichrooscytus Fieber, and Lygus irroratus Blatchley is transferred to Lygocoris Reuter. Dagbertus olivaceus Reuter is a new synonym of hospitus.

The antiaggregative pheromone 3-methyl-2-cyclohexen-1-one (MCH) of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopk.) was diffused at three rates and three spacings around attractive felled trees. Optimum treatment was ca. 1–2 mg/day at 10-ft spacing (0.06–1.3 g/acre per day), which reduced Douglas-fir beetle attacks and progeny by 96% and 91%, respectively. Progeny in trees exposed to higher than optimum MCH concentration were less mature, but not significantly fewer than progeny in controls. Densities of immature stages of nine other taxa of insects, both entomophagous and commensal, were determined. Abundance of larvae of the predacious clerids Enoclerus sphegeus Fab. and Thanasimus undatulus Say was significantly correlated with abundance of Douglas-fir beetle attacks and progeny. The predator Temnochila chlorodia (Mann.) and the associate Pseudohylesinus nebulosus (Lee.) were more dense on samples in the test area where Douglas-fir beetle population and damage were lowest. Density of the dipterous predator Medetera aldrichii (Wheeler) was correlated with numbers of beetle entrances, but decreased at high MCH concentrations. Abundance of Coeloides brunneri Vier., a braconid parasite, was correlated with numbers of beetle brood. Presence of MCH appeared to increase abundance of the associate Pissodes fasciatus Lec. and modify its distribution in trees. Use of methylcyclohexenone for preventing infestation of susceptible trees is a potential control strategy, but a more practical and effective formulation must be developed.

Three formulations of Bacillus thuringiensis Berliner, preparation Thuricide® were evaluated against a commonly occurring leafroller, Archips rosanus (L.), on filberts. In the laboratory at 26.7 ± 1 °C, all larvae died within 7 days after feeding for 48 h on filbert leaves treated with dust and wettable formulations. With aqueous concentrate, the mortality was slightly less. Insect susceptibility was markedly reduced when the length of feeding exposure period was decreased. In the field, the infestation of A. rosanus was significantly reduced within a week after treatment in almost all the treated plots. Larval mortality continued for about 4 weeks. Under western Oregon conditions, dust treatments were slightly better than wettable or aqueous concentrate formulations.

In unsprayed apple orchards in Ontario the sex ratio (female:male) of mature codling moth larvae was negatively correlated with total moth numbers, per cent fruit damage, and the fecundity of first generation females. Changes in both the larval and adult sex ratios were indicative of the tendency of moth populations to increase or decrease from one season to the next.

The reproductive behaviour of Camnula pellucida (Scudder) is described. This includes some general information on congregation on a field breeding site as well as detailed descriptions of courtship, copulation, and oviposition behaviour. Differences in behavioural patterns from those previously outlined for another major grasshopper species are tabulated.

An examination of the female genitalia of forms belonging to the redimicula complex of the genus Euxoa disclosed that the group consists of four species, redimicula (Morrison), servita (Smith), auripennis new species, and arizonensis new species. Diagnostic characters of the species in the group are discussed. A discriminant analysis was successfully used on characters of the male genitalia to segregate the males. A key to females and males of the species and subspecies of the redimicula group is included.

Discovery of the "lost types" of Xiphidium glaberrimum Burmeister, 1838, has made possible the clarification of use of several names which have been used for two species of Orchelimum. O. glaberrimum is shown to be the senior synonym for the species known as O. vulgare Harris, 1841. To preserve stability, an application has been made to the International Commission on Zoological Nomenclature to suppress both glaberrimum Burmeister and cuticulare Audinet-Serville, 1838. O. erythrocephalum Davis, 1905, is removed from synonymy with O. glaberrimum, and is the valid name for that species. Characters for distinguishing vulgare and erythrocephalum are discussed and illustrated. Type specimens are designated for glaberrimum, cuticulare, and vulgare.

A Bacillus thuringiensis Berliner formulation, with and without chitinase, was tested on various instars of Lambdina fiscellaria fiscellaria Guén. reared under various temperature conditions. The results revealed that resistance to infection increased as larval development progressed and at lower temperatures. At a given temperature, 65% of third-instar larvae died after 5 days while only 10% of fifth-instar larvae died in the same period. Chitinase increased the efficiency of B. thuringiensis for all larval instars and at all temperatures.

The egg and five nymphal instars of Plagiognathus medicagus Arrand, a pest of alfalfa in Western Canada, are described and illustrated. A key for ready separation of the nymphal instars is provided.

Platygaster taylori n. sp., reared from blackberry stem galls, is described, compared with similar species, and a list of Platygasteridae associated with blackberry in the United States of America is given.

The addition of copper to an artificial diet improves growth and survival of the house cricket, Acheta domesticus (L.), the optimum concentrations being 2 μg/g for females and 10 μg/g for males. This sex difference in requirements is attributed in part to the accumulation of copper by the larval testis. Adult males showing a loss in pigmentation, the so-called ’albino’ males, are obtained on diets low in copper; the percentage of ’albino’ males is increased by the addition of vitamin E to the diet. The pigmentation effect of vitamin E is explained by movement of copper into the testis, the development of which is stimulated by vitamin E.