The black cutworm, Agrotis ipsilon (Hufnagel), is of major economic importance in many areas of the world. In recent years, adequate methods for assessing the toxicity of insecticides to the black cutworm have been developed (Begg and Harris, 1958; Begg et al., in preparation; Harris and Mazurek, 1961). However, with the exception of the works by Crumb (1929) and Satterthwait (1933), less research has been devoted to the life history of this insect.

The sex pheromone components of European corn borer, Ostrinia nubilalis (Hbn.), from southern Alberta were identified in washes and extracts of abdomen tips from calling female moths. This is a Z strain population as (Z)-11- and (E)-11-tetradecenyl acetates were isolated in a ratio 100:2.4, and a corresponding synthetic blend in a ratio of 100:3 attracted males in the field. Dodecyl alcohol, tetradecyl alcohol and acetate, and (Z)-11-tetradecenol were also identified, but none of these components nor other "pheromone-like" mono-unsaturated C10 to C16 acetates had any effect on increasing the trap catches of male moths under field conditions. However, the addition of (Z)-9-dodecenyl acetate or (Z)-9-tetradecenyl acetate to the synthetic pheromone blend significantly reduced the capture of male moths, even though these compounds were not detectable in the female extracts. Pheromone blends used for monitoring the Z strain of the European corn borer must be essentially free, ca.< 0.1%, of these acetates. A commercially available, sticky-surface, delta-type trap was the most satisfactory of several tested for capturing moths under prairie conditions.

Inheritance of gregarious or solitary oviposition in Muscidifurax raptorellus Kogan and Legner involves two phases: (1) the female parasitoid expresses either trait shortly after mating, the magnitude of which is apparently determined by the male genome; and (2) the trait is then apparently fixed into a genome of her offspring who demonstrate it in the virgin state. In the first phase, less than one-half the magnitude of behavioral expression is shown, full expression occurring in the F1 diploid virgin hybrid. In matings with hybrids produced from subsequent backcrosses, more than one-half of the behavior is expressed shortly after mating. Traits related to gregarious oviposition (number parasitoids developed per host and total progeny) were also similarly initially expressed and subsequently inherited. A polygenic mode of inheritance is apparent, with ≥3-22 genes estimated. The extranuclear influences prior to inheritance may involve microorganisms and/or chemicals (enzymes) present in hymenopteran seminal fluid. Natural selection in this system should be accelerated by males causing the expression of a portion of the quantity of heritable behavior within the same generation.

When an apple orchard is abandoned in Eastern Canada the trees may continue to grow reasonably well for many years. As a rule the fruit is ruined by apple scab, but damage from insects or mites may be relatively minor. Under such conditions, phytophagous insects and mites are commonly held to an acceptable commercial level by natural control factors. On the other hand, when an apple orchard is abandoned in the semi-arid, southern interior of British Columbia the trees generally die from desiccation in a short time. Occasionally, when particularly favoured by sub-irrigation, they may survive for ten years or more. But they produce no marketable fruit; invariably it is ruined by insects. Unlike the abandoned eastern orchard. that in British Columbia his little natural protection from the codling moth, Carpocapsa pomonella (L.), and the blister mite, Eriophyes pyri (Pgst.), to mention but two common pests.

The genus Hoploseius is redefined on the basis of H. cometa (Berlese), H. drosophili (Chant) new combination, and H. bakeri new species, which are described, keyed, and illustrated. Fragmentary ecological data with specimens of Hoploseius make it apparent that the mites are associated with polyporous bracket fungi and have a phoretic relationship with adult drosophilid flies.

Observations mainly on sexual behavior were made in both the field and laboratory on five species representing four genera of stag beetles all occurring in central Illinois.Males of Lucanus Scopoli (= Pseudolucanus) and Dorcus MacLeay which have relatively short mandibles made direct use of these appendages in subduing and maintaining the female in position during mating.Males of Platycerus Geoffroy and Ceruchus MacLeay which have larger mandibles did not use these appendages to hold the female, but rubbed a pair of legs intermittently against the female’s elytra and had much longer matings.The presence of a female stimulus was determinant in the amount of fighting among males.

Although the extreme winter conditions of Arctic habitats are considered to be important determinants of the faunal composition of Arctic regions, the overwintering biology of most Arctic insects is unknown. A significant proportion of the insect fauna at high latitudes are hymenopterans, yet little information is available on their overwintering strategies. In this study I examined the overwintering strategies of willow gall-forming and catkin-feeding nematine sawflies and their parasitoids. All sawfly species overwintered as prepupae, were freezing-tolerant, and survived exposure to −50 °C. Freezing at high subzero temperatures was initiated by ice nucleators associated with the posterior hind gut wall. Heterogeneity of overwintering habitats with respect to temperature was not a determinant of the overwintering success of these Arctic sawflies. Divergent overwintering mechanisms were evident in the sawfly parasitoid taxa. Endoparasitoid larvae, like their sawfly hosts, were freezing-tolerant. Freezing of immature, feeding endoparasitoid larvae occurred at the freezing point of the host prepupa and was a consequence of the inoculation of the endoparasitoids' fluid compartments by ice crystals growing in the host hemolymph. Peculiarities in the structure of the endoparasitoid larval gut suggest that the site of nucleation is across the gut wall. Outside their hosts, however, endoparasitoid larvae can supercool extensively, and their tolerance of extremely low temperatures is similar to that of their hosts. Overwintering strategies adopted by the ectoparasitoids were also diverse, with both freezing-tolerant and freezing-intolerant species present in the parasitoid community. Freezing-intolerant species could not survive winter temperatures in the field in the absence of an insulating layer of snow.

The morphology and histology of the internal reproductive system of the female spruce budworm moth, Choristoneura fumiferana (Clemens), is described and discussed, with notes on the spermatophore and egg development.

Investigations were conducted to quantify the effects of treatment of cracked wheat, Triticum aestivum L. (Gramineae), kernels with sublethal and median-lethal concentrations of Bacillus thuringiensis Berliner 1915 (Eubacteriales: Bacillaceae) on the energy use by Plodia interpunctella (Hübner) 1813 and Tribolium castaneum (Herbst) 1797 larvae. Cumulative food consumption and egestion during insect development and the weight and energy values of adult insects were determined and oxygen consumption was estimated. At sublethal (4 μg/g wheat for P. interpunctella, 250 μg/g wheat for T. castaneum) and median-lethal (18 μg/g wheat for P. interpunctella, 1950 μg/g wheat for T. castaneum) concentrations, food consumption during development decreased from controls by 9.1% and 47.1%, respectively, for P. interpunctella and 14.4% and 38.2%, respectively, for T. castaneum. Egestion decreased by 9.5% and 61.5% for P. interpunctella and 19.4% and 47.3% for T. castaneum at these respective concentrations. Increasing B. thuringiensis had negative effects on food consumption and energy use by the insects. Levels of B. thuringiensis lower than required for complete control may assist in protecting grain from stored-product insects.

A strain of Bacillus cereus (Pr-1017) was isolated from dead and dying larvae of the larch sawfly. Laboratory and field feeding tests resulted in mortalities as high as 60 per cent and 38 per cent, respectively.

A positive correlation between the incidence of mortality and the mean daily temperatures was obtained in the field experiments.

Immature stages of the rodent bot fly, Cuterebra tenebrosa Coquillett, from central Washington are described and illustrated. Redescription of both sexes of the adult fly are also provided. Larval cuticular spines and posterior spiracular patterns are distinctive for second instars. Important characters of third instars include shape and number of points on cuticular spines and papillae arrangement. C. tenebrosa parasitizes bushy-tailed wood rats (Neotoma cinerea) and desert wood rats (N. lepida) in the western United States and western Canada.

Differences in weevil attack between trees containing crystallizing and non-crystallizing resin were observed. Among twenty non-crystallizers only three trees were successfully attacked by the white-pine weevil. About 50% of the remaining population was successfully attacked. Resin crystallization can thus be used as a characteristic to screen for resistance to the white-pine weevil.Since several other characteristics such as leader diameter, depth of cortical resin ducts and bark thickness are also related to weevil resistance, a discriminant function could be developed to maximize discrimination between susceptible and resistant trees by a properly weighted combination of characteristics related to weevil resistance.

Many experiments in entomology are evaluated by counts of the number of individuals in each unit of space or time. The original counts may be summarized in a frequency distribution showing the number of units containing 0, 1, 2, 3 … individuals of a given species. If a population is distributed over a number of units at random, the distribution of numbers per unit will approximate a Poisson series, the variance of the population being equal to its mean. Such distributions are rare in nature. Usually there is an excess of unoccupied units and of densely occupied units over Poisson expectation. This departure from randomness is attributable to contagion, where the presence of one insect in a unit increases the probability of others occurring in that unit. It results from the egg-laying habits of adult insects, gregariousness of feeding larvae, etc.

The spruce budworm Cacoecia fumiferana Clem. is a tortricid moth which periodically appears in vast numbers in the spruce-balsam forests of Canada and the northern United States. When these outbreaks occur, the balsam fir is often killed over areas totalling thousands of square miles. Therefore, this insect has conle to be regarded as one of the most serious enemies of pulpwood forests and has attracted a good deal of attention from forest entomologists.

The timing of diapause termination and the thermal characteristics of postdiapause development were compared in six Ontario populations of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.). The populations studied were from the major apple growing areas which are located in four climatically different zones. Pupae of all populations collected in the fall and stored under simulated overwintering conditions had terminated diapause by the end of January. Pupae overwintering under natural conditions had also terminated diapause by this time. Significant population differences occurred in the postdiapause developmental threshold (t0) and thermal constant (K). Simulating postdiapause development and emergence of the six populations using the 1981 temperature records from one location resulted in a 9-day difference between the earliest and latest mean emergence times. The implications of these results for pest management are discussed.

A sequential egg-mass sample system for Douglas-fir tussock moth, Orgyia pseudotsugata McDunnough (Lepidoptera: Lymantriidae), was designed, based on visual scanning of the lower branches of Douglas-fir trees, Pseudotsuga menziesii (Mirb.) Franco. A branch was removed from each quadrant from the upper, middle and lower crown level, and from the lowest whorl of a total of 59 non-defoliated trees in 10 areas. No consistent trend in egg-mass density per branch could be found between crown levels and no level proved superior as a representative of the tree. Therefore, the lower whorl of branches was selected for survey purposes because of sampling efficiency. Sample stop lines were determined from egg-mass density and variability data collected on 55 sites and subsequent defoliation estimates were related to these densities. The system is designed as an early detection tool to be used only in non-defoliated stands at the incipient stage of an impending outbreak.

Preserved Coleopteran remains dating to the last quarter of the 17th century were recovered from historical latrine or privy contents in Boston, Massachusetts. This analysis yielded 15 individuals of the striped flea beetle, Phyllotreta striolata (Fabricius). Its presence represents the earliest known record of this species in North America and demonstrates that it was introduced at least a century earlier than previously thought. The species history and possible modes of introduction are discussed.

Research over a 2-year period indicated that female pecan weevils, Curculio caryae Horn, tended to fly higher than males. Male pecan weevils were observed to be clumsy flyers and crawled to the pecan tree more often than females. Significant differences were noted among replicates, height flown by sexes, and distances from the tree where weevils were released. Pecan weevils do have definite habits in reaching the tree and this study seems to indicate that further investigations might be conducted to establish a method of control for the less mobile male weevils as well as for the higher flying females.

The history of the black-headed budworm, Acleris variana (Fern.), in the western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests of coastal British Columbia is one of recurring cycles of outbreaks. The latest cycle occurred from 1952 to 1957 and was represented by three main outbreaks in the Portland Canal area from Prince Rupert to Stewart, the Queen Charlotte Islands, and on northern Vancouver Island. Previous to this, groups of West Coast outbreaks were recorded from 1940 to 1945, and from 1927 to 1931 (Prebble and Graham, 1945a).

Growth rate, diapause incidence, and diapause intensity were different in two strains of corn borers found in southwestern Ontario. Crosses between these two strains demonstrated that growth rate was female sex linked while diapause incidence was male sex linked. The effect of these two characteristics on hybridization is discussed.