In Saskatchewan, Lestes unguiculatus Hagen, L. disjunctus disjunctus Walk., and L. dryas Kirby overwinter as eggs in a late stage of embryonic development. The embryos enter diapause in September and, in this condition, can survive exposure to temperatures as low as −20 °C. Under field conditions adequate snow cover is necessary to prevent egg mortality due to desiccation or exposure to air temperatures lower than −20 °C. Post-diapause development can take place at 0 °C but does not occur until the eggs are wetted as the pond fills with runoff water in the spring. Hatching in L. disjunctus and L. unguiculatus is highly synchronous and occurs when the water temperature is about 10 °C. Larval development is completed in about 60 days. Emergence is highly synchronous and is virtually complete within 10 days. Sexual maturation requires 16 to 18 days. Oviposition immediately follows copulation while the pair is still in tandem. Eggs are laid only in green stems of Scirpus L., between 5 and 60 cm above the water surface. The stems selected are those either growing in small groups or bordering larger stands. The significance of the observations is discussed in terms of the species’ ability to survive the climatic extremes of central Canada.

The average rate of diet uptake by the 1st–3rd instar nymphs of the pea aphid, Acyrthosiphon pisum (Harris), on chemically defined diets containing 0.0–5.0% amino acids varied from 0.08 to 0.23 μl/aphid/24 h and that by 4th instar nymphs to adults varied from 0.15 to 0.74 μl/aphid/24 h. The presence of amino acids increased the acceptability of diets to a great extent, as uptake on such diets was 2–5 times more than that on amino acid free diets. Uptake was lowest on diets lacking amino acids, and highest on those containing 3.5 and 2.5% amino acids by 1st–3rd instar nymphs and 4th instar nymphs to adults respectively. It is suggested that certain amino acids, either alone or in combination, act synergistically with sucrose as phagostimulants. Methionine was slightly phagostimulatory to the pea aphid and enhanced the acceptability of a free amino acid diet and of a sucrose solution.

As expected the rate of feeding increased as the aphids grew. Nymphs reached the adult stage, and reproduced on each diet, except on the one lacking amino acids. The longevity on different diets varied from 7 to 37 days. A concentration of 2–4% amino acids, with an optimum at 3.5%, appears to be essential for the growth, survival, and larviposition of the pea aphid.

Due to the punctures made in the stretched parafilm by aphids during feeding the rate of evaporation from fed sachets was significantly higher than that from unfed sachets. It is therefore suggested that in experiments where rates of feeding are measured by differential weighings of the sachets, these be renewed at 24-h intervals.

The following new Pyraustinae are described: Goliathodes n. gen., type-species G. shafferi n. sp., New Guinea and Waigeu; Spoladea mimetica n. sp., New Guinea; Meekiaria n. gen., type-species M. lignea n. sp., New Guinea; Aiyura n. gen., type-species A. linoptera n. sp., New Guinea.

The triglyceride fatty acids of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., were studied 0–21 days during the beetle’s reproductive period. Fatty acids present were identified as myristic (14:0), palmitic (16:0), palmitoleic (16:1), stearic (18:0), oleic (18:1), and linoleic (18:2). Palmitic acid increased from 12 to 23%, while palmitoleic decreased from 15 to 6% of the total triglyceride fatty acids during reproduction. Oleic acid was the predominant fatty acid in both sexes (approx. 65%) and formed 55% of the fatty acid moiety of the egg triglycerides.

The factors responsible for heavy mortality of Culex tarsalis populations in saran plastic screen cages were investigated. Two compounds, Dow Corning® Antifoam A and Aldo® MLD (glyceryl monolaurate, Glyco Chemicals Ltd.), used as foam preventatives in screen processing, were tested with C. tarsalis. One of the compounds, Aldo® MLD, was shown to be toxic to mosquitoes. Toxic principles were removed easily from saran screening by washing with detergent and water.

Females of Anthrenus flavipes LeConte emit a sex pheromone and exhibit a calling behavior that is related to the release of the pheromone. Calling began after the onset of light, was most intense 1 to 2 h later, and ceased after 4 h of light when the insects were held in a 16:8 LD photoperiod. Chemical studies showed the presence of a major sex pheromone that is an unsaturated carboxylic acid.

Euxoa antica, closely related to Euxoa terrena (Smith), is described from western United States. Adults and genitalia of both species are illustrated.

Attraction of the spruce beetle, Dendroctonus rufipennis (Kirby), to beetle-infested logs was reduced 99% by addition of 3-methyl-2-cyclohexen-1-one (MCH), the natural antiaggregative pheromone of the Douglas-fir beetle, D. pseudotsugae Hopkins. The synthetic attractant frontalin and α-pinene attracted few spruce beetles and its nominal attraction was nearly nullified by addition of MCH. Male spruce beetles responded to the natural and synthetic attractants in greater numbers than females. When MCH was added to these treatments, females predominated among the few beetles caught. The clerid Thanasimus undatulus Say was strongly attracted to treatments containing frontalin, whether or not MCH was added, but MCH alone was not attractive to this predator. Among 13 other species of scolytids caught, the most abundant were Scierus annectens Leconte and Hylastes nigrinus (Mann.). Two relatively rare species, Scierus pubescens Sw. and Xylechinus montanus Blkm., were attracted in unusual numbers to natural spruce beetle attractant. Intensive study is recommended of the possible use of MCH to prevent increase of spruce beetle populations.

Adult emergence of Simulium decorum and Simulium tuberosum was reduced or completely inhibited in air-agitated stream water by 0.1 p.p.m. slow release formulations of insect growth regulators. Abnormal pupae were produced when S. decorum larvae were exposed to 5 p.p.m. R20458-4E.

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.

Species of tenebrionid beetles in the genera Coelocnemis and Eleodes share high similarity in dorsal features. Similar species are largely sympatric in occurrence, and the distributions of some species pairs are almost identical. These congruences in appearance and geographic distribution are interpreted as evidence of Müllerian mimicry. All these beetles produce quinonoid secretions, presumably used in defense against vertebrate predators. The widespread occurrence of defensive secretions, and the similarities in dorsal silhouette and cuticular sculpturing, suggest that Müllerian mimicry is of general importance among tenebrionid beetles. The common black coloration of tenebrionids probably has an aposematic function, since black contrasts sharply with most substrates under the crepuscular lighting conditions in which tenebrionid activity typically occurs. The suitability of numerical phenetic methods for the description and analysis of convergence and mimicry phenomena is discussed.

The mechanism of sperm precedence in the spruce budworm was studied using a genetic marker. When female moths with red-eyes, a recessive trait, are mated twice within a day, first with a red-eyed male followed by a black-eyed male, three types of offspring were observed in the F1 generation. Some females produced only red-eyed offspring; another group produced only black-eyed progeny; a third group produced a mixture of both types. This indicates that sperms received from either or both matings may be utilized. The time interval between successive sperm transfers appears to be the underlying factor that determines sperm precedence in this insect; a hypothesis to explain this phenomenon is presented.

Field trials were conducted in British Columbia and Oregon in 1972, which demonstrated that trans-11-tetradecenal, a sex attractant for male Choristoneura fumiferana and C. occidentalis, is also a sex attractant for male 2-year-cycle spruce budworm, C. biennis, and that trans-11-tetradecenyl acetate is a sex attractant for male green budworm, C. viridis Free.

Hexacola sp. near websteri (Crawford), an imported larval–pupal parasite of Hippelates eye gnats, was reared in the laboratory on this host and its immature stages were diagrammed. The duration of each stage at 26 °C was as follows: egg, 2 days; first instar larva, 2 days; second instar larva, 3 days; third instar larva, 4 days; and pupa, 6–7 days. The morphological characters are compared with those of related species and the feeding activity of the larva is described.

A sex-linked mutant of the tobacco budworm, Heliothis virescens (F.), has been isolated. The wild-type pupae are brown, and the mutant pupae are yellow-bodied. The mutant (yb) could aid in sexing large numbers of tobacco budworms since > 98% of the female pupae from ± ♀ × yb/yb ♂ are yellow but all male pupae are brown. Data on mating frequency, fertility, and F1 survival of six mating types between ± or yb females and yb/yb, ±/yb, or ±/± males indicate that selection favors the wild-type genotype. When heterozygous males were crossed with either female genotype, the effect on fertility was similar to that produced by homozygous mutant males. Also, when heterozygous males were crossed with mutant females the effect on mating was similar to that produced by homozygous males. However, when heterozygous males were crossed with wild-type females, mating frequency was intermediate between that of the homozygous mutant and that of the homozygous wild-type. Survival of larvae from mutant females was lower than survival of larvae from wild-type females.

In 1972, an organophosphate resistant strain of the phytoseiid predator Amblyseius fallacis (Garman) from Michigan compared favourably with the endemic Typhlodromus occidentalis Nesbitt, from Summerland, B.C., in laboratory and greenhouse trials against European red mite, Panonychus ulmi (Koch), and was later released into an orchard. By August 1972, A. fallacis had decreased whereas population densities of T. occidentalis increased. Examination of leaves and bark from the trees, and weeds, grass, and litter beneath the trees in 1973 confirmed that A. fallacis failed to survive in the Okanagan environment.

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.

Extracellular hook electrode recordings were made of activity in the ventral nerve cord of the larvae of Orthosoma brunneum (Forster) during application of 30% CO2 to the head region. The work involved bilateral amputation of the tip segments of antennae, maxillary palps, and labial palps so that each specimen bore only one intact pair of the three sensory organs. Larvae with only intact antennae exhibited no response to CO2 in the ventral nerve cord; larvae with only maxillary palps did respond; larvae with only labial palps did respond, but less noticeably. Maxillary and labial palps are sites of CO2 reception in O. brunneum.

Entomophthora phytonomi Arthur, a pathogen recognized for many years under the name Entomophthora sphaerosperma Fres. as an important natural control agent in populations of the clover leaf weevil, Hypera punctata (Gyll.), has now been identified from the alfalfa weevil, Hypera postica (Gyll.). Both conidial and resting spore stages are described.

Early in the summer of 1973, the fungus was responsible for an epizootic in populations of the alfalfa weevil throughout much of east-central Ontario. In three study plots, mortality levels in larvae and cocoons ranged from 65–90% and 42–53%, respectively. This suggests that the fungus is capable of playing a significant role in the dynamics of weevil populations.