A visible mutation with salmon-colored eyes was found in our colony of Glossina morsitans morsitans Westwood. The trait, designated salmon (sal), is a recessive controlled by an X-chromosome locus which is at least 36 map units from ocra. Adults emerged from less than 20% of the puparia obtained by mating females homozygous for salmon with the hemizygous salmon males; these flies have very pale eyes and die at an early age. The mutant is genetically rescuable since females homozygous for salmon mated with wild-type males produced the normal number of phenotypically wild-type female offspring and about 32% of the expected number of male offspring; the males have very pale eyes.

Sex pheromone traps to control codling moth by male removal was evaluated in three orchards in the Okanagan Valley. The program was successful in only one of the three orchards. This orchard is completely isolated and codling moth control has been obtained for 5 years. In a second orchard, codling moth populations were reduced by sprays prior to the male removal program. The program was successful in 1977, as the per cent injured fruit was only 0.6. In 1978, the codling moth capture rose sharply and at harvest the per cent injured fruit was 8.0. There was a high infestation in the third orchard when the program was initiated, and in 1976, the per cent injured fruit dropped to 10.4% from 60.0 in 1975. The per cent fruit injured by codling moth rose to 37.4 in 1977 and to 60.2 in 1978 under the male removal program. Our data show that this method of control is effective only under special circumstances, where codling moth populations are low and where isolation precludes reinfestation.

A systematic analysis of larvae of 11 Nearctic species of Hygrotus Stephens was undertaken. The larvae are described and characterized; a key for their discrimination and illustrations of structural features of representatives of first- and third-instar larvae are provided. Many structural features, especially detailed variations in the chaetotaxy of cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi, were found to be useful for systematic and phylogenetic comparisons. Based on 21 larval characters, a cladistic analysis of the species studied was developed. A sister-group relationship between H. laccophilinus (LeConte) and the remaining available species is suggested. The less derived species, i.e. those without natatory setae on the legs, appear phylogenetically more closely related to the larvae of Hydroporus s.str. Hygrotus masculinus (Crotch) is the most derived species of the genus and, for many characters, seems more closely related to Hyphydrini. According to larval morphology, it is hypothesized that the genus Hygrotus diverged posteriorly to the genus Hydroporus Clairville.

Predation on adults of the crucifer flea beetle, Phyllotreta cruciferae (Goeze), by the northern fall field cricket, Gryllus pennsylvanicus Burmeister, was recorded in laboratory tests to identify predators of flea beetles that attack canola and mustard crops. In these tests, four field-collected adult crickets all ate live adult P. icruciferae, as did 15 of 16 lateinstar cricket nymphs. The tests were carried out in 60 by 20 mm disposable plastic Petri dishes, with a stoppered hole to facilitate introduction of flea beetles. A filter paper liner in the bottom of the dish gave the insects a firm footing.

Spiders (Araneae) were sampled in white spruce (Picea glauca (Moench) Voss (Pinaceae)) dominated stands from the ground and shrub layers, and from several overstorey strata to assess patterns in species composition and diversity (alpha and beta) along the vertical gradient (0–12 m above ground). Overall, 3070 adult spiders in 15 families and 76 species were collected, with the ground layer accounting for the highest species richness (40 species) followed by the mid-overstorey (36 spp.) and the shrub layers (33 species). Vertical stratification was apparent in the samples: richness clearly decreased with height, and species turnover between the ground, shrub, and mid-overstorey levels was evident, suggesting that species composition in each layer was highly distinctive. Within the mid-overstorey stratification was less obvious but both species richness and spider abundance were predicted significantly by height from the ground and branch size. Given the role of late-seral conifer stands for maintaining old-growth species, understanding diversity patterns across strata provides basic knowledge to support forest management decisions that effectively conserve spider species and assemblages. It is clearly important to include higher canopy layers in considering impacts of forestry on biodiversity in the boreal mixedwood.

Continuous trapping on the bark surface of trees infested with Dendroctonus brevicomis LeConte was carried out during six beetle generations from June 1969 to November 1971, at the University of California’s Blodgett Forest Research Station in the central Sierra Nevada mountains. Significant linear correlation was found between the density of D. brevicomis trapped on the surface of infested trees and the initial within-tree beetle densities. In the first beetle generation, mass arrival was rapid and intense (averaging 1167 beetles per 2.7 sq. dm of trapping surface on each tree, during a mean of 8.8 days). The arrival patterns during this generation were quite consistent between trees. During the second generation, mass arrival was prolonged over a mean of 19.4 days and fewer beetles were trapped ( per 2.7 dm2 of trapping area per tree). The patterns of arrival were more variable during this second generation. In generation 1, with the exception of one tree, the beetles were distributed equally at the three trapping heights (4.5, 7.5, and 10.5 m). In generation 2 they were more abundant on the traps at the lower portions of the tree.

Pre-mating behavior of male gypsy moths was investigated in 0.2 ha circular plots containing from 0 to 72 virgin females/plot in untreated areas and in areas treated with an aerial application of 20 g/ha microencapsulated disparlure. Male moths in both treated and untreated plots oriented initially to trees, not directly to females. Mating was disrupted in treated plots but males continued search behavior. No anemotactic behavior was evident in either treated plots or untreated plots with females. In untreated plots, male moths were not caught on sticky panels (panels suspended at 2, 4, and 6 m) higher than pheromone baited traps set at 2 m. In treated plots, equal number of males were caught at all panel heights and in baited traps at 2 m. Previous mating and pheromone exposure histories of males did not affect the response of these males to traps baited with 4–5 mg of disparlure in untreated plots. In a test of the relative attractiveness of a cotton wick and a new laminated bait dispenser in Johnson traps, traps baited with the laminated dispenser had a greater male moth catch/male contact to trap than the traps baited with the cotton wick. Not all males contacting the Johnson trap were caught. A mode of action for disparlure as a disruptive agent in the long range sexual communication system of gypsy moth is proposed.

Plusieurs espèces de moustiques (Diptera: Culicidae) sont des vecteurs de zoonoses d’incidence médicale et vétérinaire considérables. Une modification de la distribution géographique de ces vecteurs majoritairement engendrée par des facteurs anthropiques est actuellement accompagnée de (ré-)émergences de maladies infectieuses en Europe et en Amérique du Nord. Depuis l’avènement des insecticides de synthèse lors de la seconde guerre mondiale, les moustiques font l’objet de recherches de plus en plus étendues et approfondies. Dans une vision de lutte intégrée, les moyens de lutte anti-vectorielle se répartissent aujourd’hui selon quatre axes principaux: (1) la gestion environnementale et le contrôle physique, (2) le contrôle chimique, (3) le contrôle génétique, et (4) le contrôle biologique par le biais d’entomophages et de micro-organismes entomopathogènes. Dans ce contexte, ces derniers ont un potentiel intéressant car ils possèdent la capacité d’infecter et de tuer l’hôte avec une sélectivité plus ou moins prononcée. Cet article se propose de resituer le contrôle biologique parmi les autres techniques dans la lutte anti-vectorielle contre les moustiques, et de faire état des potentialités et des perspectives offertes par les bactéries, virus et champignons entomopathogènes. Leur utilisation sous forme de biopesticides est enfin discutée.

A method for continuous rearing of the carrot rust fly, Psila rosae (Fabricius), has been developed for the first time. All stages of the rearing were conducted in a temperature cabinet maintained at 64 ± 2°F. Adults in a screen cage were fed water, honey, soybean flour and yeast. The females oviposited in the soil of potted carrots. Eggs were periodically removed with the top layer of soil to gallon jars containing several carrots layered in muck soil.

Field collected puparia emerged satisfactorily at 70°F., but not at higher temperatures. In the laboratory population there was a preponderance of males. A generation of carrot rust flies was completed in approximately 80 days.

Experiments conducted in a plantation of oil palms, Elaeis guineensis (Jacquin), infested with bagworms, Metisa plana (Walker), tested the hypotheses that crowding enhances the incidence of larval ballooning and negatively affects the size attained by pupae. Proportions of ballooning larvae increased with increasing densities of larvae per palm. The lengths of bags (and pupal cases) decreased with increasing numbers of bagworms per leaf. Ballooning of larvae from crowded palms is likely adaptive because individuals attaining large size at pupation have proportionately greatest survival, mating success, and fecundity.

A number of reports on snow insects have been made by entomologists although many of them are brief and fragmentary. Brauer (1871) long ago considered the problem which winter represents for insect life and stated that Boreus (Mecoptera: Boreidae) and Chionea (Diptera: Tipulidae) and several members of the Collembola were true snow insects. Frey (1913) collected many insects from the surface of snow and listed representatives of the above mentioned groups from Finland, as mlell as a large number of insects whose presence on the snow was apparently accidental. Marchand (1917) made some interesting observations on the bchaviour of Chionea and its temperature tolerance and referred to several earlier papers on this genus. Handschin (1919a) carried out an extended study of the snow zone fauna of the high Alps and took many specimens on the snow or on glaciers. However, he did not list Boreus and his Diptera had not been identified when he made his report. Collembola were dealt with in another publication (1919b).

Two types of field bioassays of the relative attractiveness of various pheromone sources to Ips pini were conducted at Wanakena, N.Y., and at Warrensburg, N.Y. In the first test, the numbers and sex ratios of beetles responding to boring males from New York, Idaho, and their F1 and backcross hybrids graded down in the order of "blood relationship." The intermediate attractiveness of hybrids indicates that hybrids produce pheromones of both parents. In the second test, New York males reared in white pine attracted greater numbers of beetles than those reared in red pine and beetles boring in white pine were more attractive than those boring in red pine.

Impact of the flower- and shoot-tip-feeding beetle, Brachypterolus pulicarius (L.), on growth, flowering, and seed production of common toadflax, Linaria vulgaris (L.) Mill., was investigated using potted plants. Brachypterolus pulicarius had no effect on root or shoot biomass of attacked plants. Adult feeding by B. pulicarius delayed onset of flowering by 27 days relative to controls. Flowering of attacked plants was suppressed from mid-June until mid-July, but by mid-August flowering was similar to that of control plants. Total seed weight, individual seed weight, and percentage germination were all reduced significantly on attacked plants, resulting in a 74% reduction in number of viable seeds produced. Brachypterolus pulicarius is univoltine in Alberta, overwintering mainly as pupae.

The growth and yield responses of “Totem” strawberries, Fragaria × ananassa, to 4 introduction densities of the twospotted spider mite, Tetranychus urticae Koch, were observed under field conditions in the lower Fraser Valley. At the high-density treatments T. urticae populations peaked at 65 mites/leaflet and declined during harvest. At the medium- and low-density treatments and in the controls, T. urticae had lower and later peaks. Two species of insect predators and 1 phytoseiid species preyed upon T. urticae. Berry weight and number were predicted (R = 0.97, 12 df) from the number of flowering stalks and accumulated mite-days. Yields increased with increasing numbers of flowering stalks and declined with increasing accumulated mite-days. A $1300 yield loss/ha was observed when 2500 mite-days accumulated between 15 May and 16 July. Fruit size was not affected by T. urticae. Yield equations were developed so that a mite sample 1–5 weeks before harvest can be used to predict dollars lost due to T. urticae. The data allow the grower to determine an economic threshold based on the number of weeks before harvest, mite sample precision, differences in environmental conditions relative to the present study, the control measure to be used, and the market price to the grower.

Definite records of injury by the larch sawfly (Lugaeonematus erichsoni Hartig.) in North America only date back to 1881 when Hagen records the insect from Massachusetts. Horv long it had existed on the continent previous to that date is uncertain, but judging from its distribution at the time it was first reported, we may safely conclude that it had been present for a number of years. There is indeed a significant statement by Audubon in which reference is made to the larches being stripped, by a “green caterpillar some three quarters of an inch in length,” which if referable to this sawfly would take our records back to the beginning of the last century.

Among others, Schwerdtfeger, 1931, Gosswald, 1934, and Morris, 1949, have used frass-drop samples as indirect measurements of the density of forest insect populations with some success. The method has also been used to assess the effects of various insecticides on the feeding of treated larvae (Rhumbler, 1929; Schwerdtfeger, 1930) and to study the influence of weather upon the feeding and development of forest insects (Monro, 1935).

Two aspects of the biological control of R. buoliana are reported in this paper. From 1949 to 1957 rearing techniques were developed for and observations were made of the abundance and biology of parasites received in host material that was collected in Europe (Arthur). From 1955 to 1959 a critical evaluation of the parasites was made, largely based on a study at Elmira, Ontario, of the biology and habits of five representative parasitic species in the field and the laboratory to determine factors that limit their efficiency (Juillet).

Second-instar nymphs of Leptoglossus corculus (Say) confined to shortleaf pine conelets for only 4 days caused 100% conelet abortion. The bugs fed almost exlusively on the cytoplasm of cells of the nucellar tissue. Feeding in May produced an abscission zone in only a few days and resulted in conelet abscission in less than 2 weeks. Similar ovule destruction, followed by conelet abortion, occurred in late summer after being fed upon by the same instar, but conelet abscission was prevented because of a greater proportion of tracheary elements in the conelet stalks.

A single 7.5-min injection of 0.6 p.p.m. of methoxychlor into the North Saskatchewan River eliminated 100% of instars 3 to 6 inclusive of the larvae of Simulium arcticum Mall, from sites 40 and 80 km downstream, 91% at 121 km, and 66% at 161 km. Ninety-six per cent of the larvae less than 1 mm long were removed from the 161-km site. Plecoptera larvae were similarly affected. Chironomidae, Ephemeroptera, and Trichoptera were least affected.

The treated portion of the river was rapidly repopulated by insect larvae. None of the pretreatment taxa disappeared and in fact many new ones appeared, during the 10 weeks immediately following the treatment. In all four sites examined in the treated portion of the river, population densities of Chironomidae larvae larger than 1 mm long equalled or surpassed the pretreatment densities within 1 to 3 weeks, Ephemeroptera within 1 to 4 weeks, Trichoptera 1 to 7 weeks, Plecoptera 4 to 5 weeks, and Simuliidae in 2 to 10 weeks. Populations of larvae smaller than 1 mm long were generally restored more rapidly. Procedures for an annual abatement programme for S. arcticum in the Saskatchewan River are outlined.

Chromosonial studies have elucidated phylogenetic relations in Drosophila (White, 1954), culicids (Jucci, 1952) and chironomids (Bauer, 1936, 1945). Since it appeared promising to apply this approach to the Simuliidae, Rothfels and Dunbar (1953) began a cytological survey of the black flies of eastern Canada during the summer of 1951. They found that in this group the giant salivary gland chromosomes provided “a wealth of descriptive morphological detail in their number and gross morphology, in the characteristics of expanded centromere regions, in the location of specific nucleolar sites, in the degree of pairing of constituents, and in the ultimate discernible banding pattern…. Since these features are not functionally related to the external environment, the confusing effects of convergence are minimized, resemblances may be taken to indicate relation, and grouping is possible according to natural affinities” (Rothfels and Dunbar, 1953).