Male and female adults of Mideopsis (Nudomideopsis) magnacetabula n. sp. are described. This is the first species of this subgenus described from the New World, and knowledge of the new species necessitates modification of the subgeneric concept.

An energy budget was evaluated for the bertha army worm, Mamestra configurata (Walker), over its life cycle. Cumulative values for the budget at the end of larval development were: ingestion, 2124 cal; respiration, 372 cal; production, 485 cal; and egestion, 1266 cal. The sixth instar larva accounted for 80.1, 83.2, 81.3, and 78.8% of the total energy in ingestion, respiration, production, and egestion, respectively, during its development. Assimilation efficiency varied from 35.5 to 44.4% with a mean of 40.6%, gross production efficiency varied from 16.6 to 23.8% with a mean of 21.3%, and net production efficiency varied from 37.5 to 61.3% with a mean of 52.7%.

Intensive and systematic laboratory studies conducted under various experimental conditions (larval stage, physiological condition of the insect, temperature, formulation) revealed that non-crystalliferous strains of Bacillus thuringiensis Berliner and B. cereus Frankland and Frankland were equally pathogenic for larvae of Choristoneura fumiferana Clemens as the crystalliferous strain of B. thuringiensis tested. Also the addition of minute quantities of chitinase (10,000 UN/ha) considerably increased the efficiency of commercial preparation of B. thuringiensis against C. fumiferana.

At 20°C, B. thuringiensis var. kurstaki provoked a slow septicemia in 3rd instar larvae of C. fumiferana which resulted in 90% larval mortality in 27 days. Under the same experimental conditions, a non-crystalliferous strain of B. thuringiensis (No. 17) and two strains of B. cereus, entomopathogens isolated from C. fumiferana and from a Tachinidae, also caused a slow septicemia resulting in 90% mortality of 3rd instar larvae after 30 to 32 days.

Experiments revealed that the symptoms of infection (lethargy, loss of weight) caused by B. thuringiensis + chitinase were far more rapid and pronounced than those provoked by B. thuringiensis alone The commercial preparation 26B prepared by Sandoz-Wander, applied at a rate of 16.8 × 109 BIU/ha caused only 80% mortality of 3rd and 4th stage larvae, while the complex Sandoz + chitinase N.B.C. provoked 100% larval mortality between 9 and 27 days depending upon the experimental conditions used Similar results were obtained with Dipel 36B. For instance, at 20°C Dipel + chitinase N.B.C. provoked 100% mortality of 3rd stage larvae in 9 days, while with Dipel alone, the same level of mortality was reached after 24 days. Also, it was established that C. fumiferana larvae reared on Abies balsamea were far more susceptible to the action of the bacillus than those reared on artificial diet.

These results confirmed that addition of chitinase considerably increased the pathogenic properties of B. thuringiensis on C. fumiferana and the low efficiency of the bacillus alone. The addition of chitinase to commercial B. thuringiensis preparations is required and of prime importance in future use of B. thuringiensis for the control of this insect pest.

The pink bollworm (Pectinophora gossypiella (Saunders)) is an important pest of cotton in the desert areas of the United States and Mexico, as well as other areas of the world. The literature on this pest is quite extensive, and hence, beyond the scope of this paper. Work by McLaughlin (1974), Lukefahr (1962), Watson et al. (1973), Slosser and Watson (1972), Adkisson et al. (1963), and Westphal et al. (unpublished) have been extremely useful in providing a satisfactory data base for formulating a mathematical description of the biology of this pest species (i.e., a time varying life table model—Hughes (1963), see Southwood (1966)).

Samples of a population of Argia vivida Hagen larvae were taken at about monthly intervals from a series of warm sulphur pools at Banff, Alberta, from June 1973 to December 1974. Changes in head capsule width and wing pad length in field-collected and laboratory-reared specimens show that the life-cycle is univoltine. Only the final (Z) instar can be recognized with certainty, but methods are described whereby the population can be divided into size classes which are thought to correspond well with the last nine larval instars. Periods of rapid growth occur in the autumn and again in the spring. Larvae overwinter in the instars U, V, W, X, and Y and the major shift to the final instar occurs in March and April. Adults emerge from April to August. In the laboratory, growth is temperature dependent until the penultimate (Y) instar and this could be a factor in the field since, although larvae can exist year-round at a constant 26 °C, some larvae live in the cooler areas at the edges of the streams and pools. Entry to the final instar appears to require the long photoperiods that follow the vernal equinox.

An abdominal tip extract of female bertha armyworm moths, Mamestra configurata (Walker), was found to contain two sex pheromone components. One corresponded to (Z)-11-hexadecen-1-ol acetate, previously identified from this source, and the other to a tetradecen-1-ol acetate, identified by gas chromatography – mass spectrometry. Data obtained from the EAG profile of isomeric tetradecen-1-ol acetates indicated the active component to be (Z)-9-tetradecen-1-ol acetate. Neither of these two acetates was by itself attractive to males in field tests; however, mixtures were attractive, with the best attraction occurring with a C16:C14 acetate ratio of about 19:1.

Apple orchard tests in 1974, 1975, and 1976 showed that applications of granulosis virus reduced deep-entry damage by larvae of the codling moth, Laspeyresia pomonella (L.), to apple fruit at harvest by 55 to 96% compared with damage to fruit on nontreated check trees. Sting or shallow-entry injury was usually higher on virus-sprayed trees than on check trees presumably because larvae were killed by the virus soon after entry into the apple.

An inventory was taken of aphid species occurring on balsam fir, white spruce, larch, red pine, white pine, jack pine, and black spruce at two sites where the introduced red wood ant, Formica lugubris Zett., had been released. Twenty-one aphid species were found, all in the genus Cinara Curtis. Nine of these species, and possibly a tenth, were new records for Quebec. Observations on colony size and distribution on host trees, in ant infested and control blocks, were recorded.

To date no entirely satisfactory control method has been developed for the European skipper, Thymelicus lineola (Ochs.), which was first introduced into North America in London, Ont., around 1910 (Saunders 1916) and has since spread throughout much of Canada and northern United States (Arthur 1966; Burns 1966; McNeil et al. 1975). In Quebec this insect has reached epidemic proportions in several areas (McNeil et al. 1975) and while Sevin® has been utilized, its application causes certain undesirable off-target effects. It is therefore essential to develop a means of control which does not cause these ecological problems.

The larvae of Macrotheca angulalis Barnes & McDunnough and Alpheias sp. are described and illustrated. A comparison is made between these and the larvae of Galleriinae.

Larval growth in B. terricola Kirby was measured from daily photographs of the combs of colonies. The growth rate of well-fed larvae was exponential until the commencement of cocoon spinning. No difference between the instantaneous growth rates of physiologically determined workers and queens developing in the same larval clump could be detected. Queen morphogenesis consisted principally of an extended stadial duration as compared with workers. Larvae which were starved regained their former growth rates once they were again fed plentifully. As a general feature of larval growth in Bombus it is suggested that the capacity to resume growth at an invariant maximal rate is retained under widely varying trophic regimes. Thus larval growth in bumble bees is interpreted as a succession of bursts of maximum proportional increase separated by periods of temporary starvation induced both by irregularities in colony food intake and the inherent stochasticity of worker feeding behaviour.

The overwintering mature larva of the parasite Anastatus disparis Ruschka within the intact gypsy moth, Lymantria (= Porthetria) dispar L., egg chorion is susceptible to freezing and has a mean supercooling point of −28.8±0.14°C. This level of cold hardiness is not increased by exposure to sublethal low temperatures. Over 85% of larvae survived 10 months at 0°C and 4 days at −12° or −18°C, both followed by an additional 2–3 months at 0°C, but over half of the survivors went into prolonged diapause which was not fulfilled by subsequent rearing at room temperature. The parasite is apparently capable of surviving winter conditions over the same geographic area in Canada as the gypsy moth, and the introduction of A. disparts into locations in Canada where gypsy moth is now present is recommended.

Storage of diapausing larvae of Choristoneura viridis and C. occidentalis at low temperature (2°C) appeared to be sufficient stimulus to terminate diapause. Reactivation at 25°C occurred sooner and was more synchronous with longer storage at 2°C. Highest survival was obtained after storage of 20 to 22 weeks for both C. viridis and C. occidentalis. Intraspecific and interspecific reactivation rates were compared by analysis of covariance, using the model ln Y = a + B ln X , where Y = larval emergence in days at 25°C and X = storage in weeks at 2°C. Intraspecific sex differences were not significant, indicating that protandry observed in this laboratory in both species must be due to some other factor. C. viridis had substantially less stringent thermal requirements for diapause termination than C. occidentalis. Diapause in the two species is discussed.

Pupal diapause in Athrycia cinerea (Coq.), a larval parasite of bertha armyworm, Mamestra configurata Walk., was usually prevented if the parasite larvae were reared at 25°C, but not if they were reared at 20°C. Mature larvae of the parasite were more sensitive than younger larvae to this temperature effect. Diapause incidence in A. cinerea at 20°C was not reduced by using only young parent females for oviposition; by rearing the parent females at a high temperature (25°C) and long day (16 h) prior to and during oviposition; by using host larvae that had been light-programmed for non-diapause; or by increasing the photoperiod, to which the parasite larvae were exposed, from 12 to 16 h. Termination of pupal diapause was accelerated by low temperature; at least 24 weeks at 2 °C were required to synchronize adult emergence.

Nymphs and adults of Gerris remigis Say were collected for 7 months from a stream with only this species of Gerridae. The colour markings of the nymphal stadia are described and illustrated. Measurements of antennal and hind limb segments are given and these can be used to distinguish successive instars.

Adults of Trisetacus chamaecypari n. sp., and female adults of T. thujivagrans n. sp. are described, and species of Trisetacus associated with Cupressaceae and Taxodiaceae are discussed and keyed. An original diagnosis of the genus Trisetacus is included.

This paper resurrects the genus Tethallotrum Scudder 1962 from synonymy and compares it with Allocentrum Bergroth 1894. A new species Allocentrum impunctatum is described from Madagascar.

Field studies in Ontario, Oregon, and California on interspecific attraction and inhibition among the coniferophagous species of Choristoneura (the spruce budworm and its allies) confirmed specific pheromonal differences among the species. Of the three species that are mutually attractive and whose males are attracted by blends of trans- and cis-11-tetradecenal, C. fumiferana, C. biennis, and C. occidentalis, catches of C. fumiferana males in traps baited with C. fumiferana females were significantly reduced by the presence of females from a second group in which it is believed the females produce trans-11-tetradecenyl acetate. Catches of C. occidentalis males by C. occidentalis females were not affected in this way. F1 hybrids and backcrosses between an aldehyde-producing species and an acetate-producing species produced females that were attractive to males of one or other of the parent species, although some females were not attractive to either. Individual females never attracted males of both parent species, and of those that were attractive, more were attractive to males of the aldehyde species than to males of the acetate species. The results suggest sex-controlled inheritance and expression.

Parasitoids of the overwintering generation of the introduced pine sawfly were surveyed in Minnesota. The parasitization rate was greatest in cocoons collected from foliage in fall 1971, but there was nearly complete mortality of sawflies and parasitoids in cocoons above the snowline by April 1972. Monodontomerus dentipes (Dalm.) most commonly emerged from cocoons collected from trees and shrubs in fall 1971. Exenterus amictorius (Panz.) was the most common parasitoid of cocoons collected from duff in both 1971 and 1972.