Polyacrylamide gel (6%) electrophoresis (at pH 8.2) of the thoraces of adult Glossina morsitans morsitans Westwood revealed three xanthine oxidase (XO) phenotypes and six aldehyde oxidase (AO) phenotypes. Each enzyme was postulated to be under the control of a single locus, XO with two alleles and AO with three alleles. Gene frequencies were in Hardy-Weinberg equilibrium for both loci in two laboratory populations. Breeding experiments provided direct evidence for single locus control of each enzyme. No significant differences in phenotype frequencies were observed between the colony maintained at the University of Alberta, Canada and the parent colony at the University of Bristol, England. A colony of highly inbred flies from the University of Bristol had only one phenotype of AO and of XO.

The digestive section of the midgut of Glossina morsitans morsitans Westwood contains a phosphatase with a pH optimum of approximately 9.2 and with low substrate specificity; the enzyme was classified as an alkaline phosphatase (E.C. 3.1.3.1).

Polyacrylamide gel (6%) electrophoresis (at pH 8.9) of the digestive portion of the midguts of adult G. morsitans morsitans revealed three alkaline phophatase phenotypes. Midgut phosphatase was postulated to be under control of a single locus (designated alkph) with two alleles. Gene frequencies were in Hardy-Weinberg equilibrium in two laboratory populations while a third, highly inbred population had only one phenotype. Phenotype frequencies were not significantly different among females of various ages from the Edmonton colony. Breeding experiments provided direct evidence for single locus control of midgut phosphatase.

Three new species of Micropeplidae are described from Latin America, Micropeplus newtoni from Mexico, Peplomicrus mexicanus from Mexico, and Peplomicrus pecki from Colombia, bringing the total number of New World species to 21. A revised key to aid in the identification of the Micropeplidae of Latin America is presented. New distributional data are given for 10 other species of the family and revised distributional maps are given for the North American species Micropeplus sculptus, M. laticollis, and M. robustus.

A plot of 6 m tall white spruce trees was treated with an aerial application of an oil-base spray containing a non-toxic compound, Tris (2 ethyl hexyl) phosphate (referred to as TOF), which was amenable to gas-liquid chromatographic analysis The spray was formulated and applied at a rate to approximate the eastern Canadian operational spruce budworm control sprays. Meteorological measurements were made in the airspace from mid-crown height to the height of spray emission for the period of spray application and deposition. Spray deposit collection units (kromekote cards and glass plates) were used to record spray deposit at ground level.

Foliage samples and complete branches were taken from each of three trees at a series of heights and each of the four compass quadrants and returned to the laboratory for chemical analysis. Spray deposit was determined in terms of ppm TOF on the foliage. The kromekote cards provided information from which the drop size characteristics of the spray cloud and the deposit in terms of drops/cmK were determined; a colorimetric analysis of spray deposit on the glass plates indicated the volume of spray deposited.

Analysis of the spray deposits on the foliage indicated gradients in deposits with most on the upper, outer, upwind portions of the trees and least on the lower, inner, downwind portions. These differences were significant. These gradients can be attributed to two weather factors (a) the prevailing wind drifting the pesticide cloud through the forest canopy resulting in a filtering to produce a decreasing gradient from upwind to downwind side of the tree, and (b) air eddies around the tree tops resulting in an increased deposit and slight penetration of the spray cloud on the outer downwind portions of the tree.

This study demonstrates that a finely atomized spray applied to a white spruce forest under suitable weather conditions will give a deposit on the outer portions of the tree with a variation of only about 50% in spray deposit but with significantly less deposit on the inner, lower portions of the tree.

The bioactivity and disappearance of chlorpyrifos in Dursban® 2.5 G and M formulations was studied in the laboratory and in the field in temporary pools lined with sod, clay, or sand substrate. The activity and presence of chlorpyrifos in the water was determined by bioassay with Culex tarsalis Coquillett larvae and chemical analysis by gas-liquid chromatography.

The tests indicated that, at equal rates of application in pools with organic matter or clay substrate, the 2.5 G formulation resulted in lower chlorpyrifos concentrations than the Dursban M, but provided periods of larval mortality equal to or greater than the M formulation except in laboratory sod-lined pools. At a given application, the shortest period of larval mortality and lowest detectable residues occurred in sod-lined pools, whereas in the sand-lined pools, the longest period of larval control and the highest residual concentration of chlorpyrifos in the water was encountered.

Limonia (Idioglochina) marmorata (Osten Sacken) is the only intertidal tipulid along the entire west coast of North America. The pupae have prominent prothoracic respiratory horns which are modified to form plastron-bearing spiracular gills. Examination of these gills by both light and scanning electron microscopic methods reveals that they resemble the spiracular gills of the intertidal Limonia (Geranomyia) in general form, but in fine detail they more closely resemble those of the intertidal species of Limonia (Dicranomyia). Using the fine structure of the spiracular gills as a classificatory feature along with larval and adult characters, it is suggested that there is little distinction between Idioglochina and Dicranomyia at the generic level. This confirms the contention of Hinton and also lends weight to the classificatory scheme of Alexander, who distinguishes Idioglochina and Dicranomyia only at the subgeneric level.

Two metal granaries each containing 27.3 tonnes of dry wheat (13–14% m.c.) were artificially infested with Cryptolestes ferrugineus (Stephens) and sampled for up to 4 years to determine fluctuations in insect density as influenced by changes in grain temperature and moisture content during storage. Density remained low (fewer than 5 insects/kg) throughout the period of study. Most insects were found at the floor near the wall on the south side of the granary. The temperature in the centre of the grain mass ranged from −5° to 22 °C during the 4 years. During a single season, moisture content varied as much as 5% at the centre near the surface of each grain mass, but did not vary more than 1% at other locations. In the first year of storage, the viability of the wheat ranged from 80% to 96%, and after 3 years in storage, 68% to 100%. Since no significant change was recorded in the temperature, moisture content, or germination of the wheat in the granaries, it was concluded that the biological activity of a low density population of C. ferrugineus does not initiate heating that occasionally occurs in farm-stored grain in Canada.

Using Dyar’s Law the number of larval stages in the life cycle of the European skipper, Thymelicus lineola, was determined in Quebec (1974, 1975, 1976), Ontario (1976), and Prince Edward Island (1976). In all regions five larval stages were observed, as in Europe, and not six as previously reported in Ontario. Apparently in this latter case an erroneous interpretation of the significant differences existing between the sexes (relating to head capsule width and developmental time) resulted in male and female fifth stage larvae being considered as fifth and sixth stages respectively.

Three species of Twinnia, including hirticornis n. sp., and five species of Gymnopais, including dichopticoides n. sp., holopticoides n. sp., and fimbriatus n. sp., are described, keyed, and illustrated. The ancestral simuliid is portrayed as possessing cephalic fans, because several related nematocerous families, viz., the Ptychopteridae, Dixidae, and Culicidae, also have similar and presumably homologous structures in the larval stage which are used in the same fashion to ingest food particles suspended in water The peculiar Twinnia–Gymnopais larval type, which lacks cephalic fans, is considered to have arisen simply by a neotenic retention of the fanless condition found in the first instar of Prosimulium. Phylogenetically, Twinnia and Gymnopais are therefore considered to have been derived from a Prosimulium-like ancestor. Twinnia is intermediate phylogenetically between Prosimulium and Gymnopais, and the latter is believed to be the most recently derived, possibly as a response to the development of arctic–alpine conditions in Beringia during the Tertiary.

A local population of P. apachus in California was studied to determine population structure and colony survival during the first 3 months of colony development. Only 24.2% of the colonies survived to the end of July. Bird predation on colonies (60.6%) and loss of foundresses (12.1%) were the main causes of colony failure. Bird attacks occurred approximately 2 weeks prior to the emergence of workers and the scrub jay, Aphelocoma coerulescens, was identified as one of the avain predators. All colonies that survived this initial period persisted until observations were discontinued in late July.

A single collection from a beaver lodge near George Lake, Alberta (53°57′ N., 114°06′ W.), in mid-May 1976 yielded 1362 female Anopheles earlei Vargas, of which 39.2% were blood-fed and 3.1% gravid. The mosquitoes could have overwintered in the lodge and fed on the beavers, but they could also have flown in from other overwintering and feeding sites earlier in the spring.

Survivorship of the citrus blackfly was greatest at 25.6 °C and decreased in either direction from this temperature. A series of linear equations were derived to describe stadium length in thermal units for each development stage of the citrus blackfly and for the complete life cycle. There was no significant difference between the calculated stadium lengths and those observed in the field using linear thermal units.

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.

Males and females of Phlebotomus vexator occidentis Fairchild and Hertig and P. aquilonius Fairchild and Hardwood were collected from burrows of yellow-bellied marmots, Marmota flaviventris nosophora Howell, in southern Alberta. P. v. occidentis adults were collected from burrows at collecting sites at Police Coulee (111°39′ W. long., 49°3′ N. lat.) and Lethbridge (112°52′ W. long., 49°39′ N. lat.), whereas P. aquilonius adults were collected only at the Police Coulee site. The Lethbridge location is a new northern limit for distribution of P. v. occidentis. The seasonal occurrence of adults of P. v. occidentis is July to September and P. aquilonius is August to mid-October.

The eggs of Nabis alternatus Parshley, which are laid in the stems of alfalfa plants, can be identified by their opercula, which protrude from the stem. Most eggs were laid in the upper portion of the main stem where the mean widths of the stems were 1.5 to 1.7 mm, and the hardness averaged 7.4 kg. The mean and minimum heights of oviposition increased with increasing total height of stem and the number of eggs laid also increased. Eggs laid in alfalfa stems that were subsequently allowed to dry had low percentage hatch.

The apple leaf midge, Dasineura mali (Kief.), was first noted in a New Brunswick commercial apple orchard at Waweig, Charlotte County, in 1964. Adults collected there in 1965 were identified by Biosystematics Research Institute. The midge's first appearance in the Saint John River Valley was in 1968 in York County. Since 1968 this insect has spread to infest orchards up river as far as Woodstock and down river to orchards in the Gagetown-Queenstown area.