An IPM program was developed to control Venturia inaequalis (Cke.) Wint., Lygus lineolaris (Palisot de Beaiivois), Conotrachelus nenuphar (Herbst), and Rhagoletis pomonella (Walsh), the annual key pests of apple orchards in southwestern Quebec. The program was found to control other pests, such as Orthosia hibisci (Guenée). Phytophagous tetranychids were controlled with the introduction of an organophosphate-resistant strain of Amblyseius fallacis Garman, Key pests were monitored carefully and pesticide applications were timed to correspond to their presence in the orchard. After an extremely severe winter and late spring frosts, the IPM program failed to provide commercially acceptable pest control. A measure to correct this problem is suggested in the text. This program reduced the cost of pesticide treatments by 34% when compared with pest control practices currently used by commercial growers in Quebec.

Determination of the spatial pattern and estimation of the density of egg, larval, and adult populations of Ctenicera destructor (Brown) and Hypolithus bicolor Eschscholtz were made by soil sampling, and for C. destructor adults, also by cages that collected the emerging adults in the spring. Eggs of both the above species and also those of Aeolus mellillus (Say), which were also found in the samples, were highly aggregated. Small C. destructor larvae were most highly aggregated and medium larvae less so; large larvae were usually randomly distributed. Unlike C. destructor, large H. bicolor larvae were more highly aggregated than either the small or medium bicolor larvae. Sampling by emergence cages showed that C. destructor adults were aggregated while sampling by soil cores showed them to be randomly distributed. The different result obtained by the two methods was attributed to the difference in the size of the sampling unit. Aggregation was detected in 29% of the H. bicolor adult population sampled by soil cores only.

Larval densities of C. destructor ranged from a low of 0.25 to a high of 1.46 per sample unit (81 cm2) over the 14-year period that samples were taken; densities of H. bicolor ranged from 0.16 to 0.64. Densities of C. destructor and H. bicolor adults averaged about 6 (range 1–16) % and 12 (0–27) % of the total population of larvae and adults for each respective species. Population composition, in terms of adults and larvae of different sizes, and population fluctuations are discussed.

The relation between density and the number of sampling units required to achieve four levels of margin of error at four levels of statistical significance was determined.

No satisfactory transformation was found for data of individual samples with a mean less than 1. Several common transformations, including Taylor’s power transformation, were satisfactory for stabilizing the variance of pooled samples.

During September, 1950, 23,180 specimens of the European earwig, Forficula auricularia L., were collected in Vancouver, British Columbia, for the purpose of recovering the imported parasite Bigonicheta setipennis (Fall.). Great fluctuations were observed in the number of insects caught from day to day. This paper is an attempt to assess the role of various climatic factors in these fluctuations.

The obliquebanded leafroller, Choristoneura rosaceana (Harris), is a polyphagous insect that is occasionally a serious pest of apple trees. To determine how well adapted it is to this host plant, we studied its nutritional ecology by measuring the development and mortality of larvae and pupae reared on different sets of leaves. We investigated the influence of 3 apple cultivars, 2 time periods (June, July–August), and several leaf types, including those with different ages and different branch positions, on these processes. Larvae and pupae developed more rapidly with lower mortality on younger leaves than on older ones. When larvae were fed leaves collected from the same cultivar and branch position at different times during the season, developmental rates were faster and survival rates were higher earlier in the season. Development and survival were similar on leaves of all cultivars.

Methamidophos proved more suitable than methomyl for incorporation in an integrated pest management program for celery. Methomyl applications resulted in increased leaf mining and greater emergence of Liriomyza species leafminers. Methomyl use also increased adult parasite mortality, and significantly reduced the rate of parasitism by approximately 50% as compared to methamidophos or control treatments. Species composition of parasites was influenced by pesticide treatments; the Diglyphus species, Chrysocharis species and Halticoptera circulus (Walk.) demonstrated tolerance, but Chrysonotomyia punctiventris (Crawford) was intolerant.

Carrot rust fly (CRF), Psila rosae (Fabricius) (Diptera: Psilidae), caged with 2-month-old carrot plants at 20 °C, 50–70% RH, and 16:8 L:D laid an average of 109 eggs per female. With ca. 50% survival from egg to pupae, the rearing procedure yielded a 25 × population increase per generation. The duration of the life cycle at 20 °C was ca. 65 days. Calculated threshold temperatures and degree days above those temperatures necessary for complete development were: eggs, 4.5 °C and 94 degree days (°D); larvae, 2.02 °C and 625 °D; and pupae, 1.47 °C and 374 °D. Larvae collected in the field in fall developed normally when incubated at 22 and 19 °C; ca. 40% of the pupae entered diapause at 16 °C, and 100% at 13 and 10 °C. Fall-collected larvae chilled at 1 °C for ca. 3 months developed normally at all temperatures including those which induced diapause in pupae from unchilled larvae. With laboratory-reared pupae, 100% diapause was induced with > 10 days exposure to 13 or 10 °C. Twenty weeks storage at 1 °C was sufficient to terminate diapause in > 95% of the pupae. The ability of both CRF larvae and pupae to survive cold temperature conditions suggests that 2 separate spring emergence peaks may occur, which could have important implications if the spring flight is to be predicted on the basis of °D accumulations.

Chow and Mackauer (1984) recently reported on inter- and intraspecific larval competition between Aphidius smithi Sharma & Subba Rao and Praon pequodorum Viereck (Hymenoptera: Aphidiidae), when both were parasitizing the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae). In interspecific competition, a 1st-instar Praon larva usually eliminated, by physical combat, an Aphidius larva that was up to 48 h older. However, circumstantial evidence suggested that once an Aphidius larva had reached an advanced stage of the final (4th) instar, it was able to complete development and pupate, even in the presence of a younger Praon competitor.

Parasites of the sawflies Neodiprion abbotii (Leach), N. abietis (Harr.), N. lecontei (Fitch), N. nanulus nanulus Schedl, N. pinetum (Nort.), N. pratti banksianae Roh., N. swainei Midd., and the N. virginiana Roh. complex are separated by using characters of the parasite remains in the host cocoons from which the parasites emerged. Characteristics of the cast skin of the last larval instar of 11 species are described and illustrated in this paper; the remaining 29 species were described and illustrated in earlier papers (Finlayson, 1960a, 1960b, 1962). Keys are given to separate the species of the genera Exenterus and Lamachus that attack the above hosts, using characters of the cast skin of the last larval instar.

The toxicities of acephate, aminocarb, carbaryl, chlorpyrifos, chlorpyrifos-methyl, methomyl, mexacarbate, permethrin, and trichlorfon to last instar western spruce budworm, Choristoneura occidentalis Freeman, were significantly altered by the presence of host-plant foliage. The pyrethroid permethrin was significantly more toxic when sprayed directly on fully exposed larvae than when first sprayed on foliage. However, all other toxicants were more toxic sprayed on foliage. A toxicologically-based method was used to assess the residual toxicities of the nine chemicals. Each chemical was applied to potted seedlings at its respective LD90-foliage, then weathered for up to 7 days. Significant differences in toxicity were related to both insecticide and weathering interval. The toxicities of carbaryl and permethrin were least affected by weathering.

Traits that function in male–female sexual interactions tend to diverge rapidly compared with other traits. Several hypotheses attempt to explain this evolutionary pattern. Predictions of two of these hypotheses, lock-and-key and sexually antagonistic morphological co-evolution, were tested by examining how two sets of species-specific male structures fit with female structures during courtship and copulation in the fly Sepsis cynipsea (L., 1758). Contrary to predictions of both hypotheses, neither the species-specific modifications of the male's front legs nor those of his genitalic surstyli were matched by modifications of the female structures with which they meshed (wing bases, 6th abdominal sternite); males damaged small patches of microtrichia on the female's wings with their legs, but the morphology of the female's wings and abdomen showed no sign of the defensive designs expected under antagonistic morphological co-evolution. Data regarding the alternative hypothesis of sexually antagonistic behavioral co-evolution by females in response to male morphology were less conclusive, but this hypothesis failed to explain the sustained, apparently stimulatory rhythmic squeezing by the male genitalia and the lack of female defensive responses to this squeezing. These movements of the male surstyli during copulation suggest that they function to stimulate the female. The wing base of the female has apparent sense organs near the sites contacted by the male, as expected under the alternative hypothesis of traditional female choice to explain rapid divergent evolution. The male's genitalic surstyli were also used in novel precopulatory interactions. A pair of previously undescribed processes at the bases of the surstyli probably grasp and may also rhythmically squeeze the female during copulation.

The egg laying regime of Forficula auricularia L., defined by different parameters (number of broods, proportion of females that produce two broods, number of eggs produced at each batch, and the proportion of the total number of eggs represented by the first batch), was studied in the laboratory and under seminatural conditions for a population from Montréal. Approximately half of the females produced two batches of eggs in the laboratory; however the number of eggs produced in the first batch was substantially higher than that of the second batch. In the field a single batch of eggs was produced. Comparison of our data with the literature showed that the Montréal population appears to have a greater resemblance to one of a cold temperate climate (Font-Romeu, Eastern Pyrénées) than one of a warmer climate (Rennes, Bretagne) for all parameters studied.

The morphology of the stylets of the six-spotted leafhopper, Macrosteles fascifrons (Stål), is described from light and transmission electron microscopy. The maxillary stylets are about 1/5 longer than the mandibular stylets. Both pairs of stylets contain central ducts running from their bases to their tips. The duct in the mandibular stylet is unbranched but that in the maxillary stylet bifurcates midway toward the tip. The mandibular duct contains 3 dendrites; the maxillary duct contains 5 dendrites. The fine structure of the dendrites is described.

In 1999, the leaf roller Caloptilia fraxinella (Ely) (Lepidoptera: Gracillariidae) was noticed for the first time in the city of Edmonton, Alberta, Canada, on ornamental green ash (Fraxinus pennsylvanica Marsh. var. subintegerrima (Vahl) Fern.) and black ash (F. nigra Marsh.) (Oleaceae). It has since been found there on Manchurian ash (F. mandshurica Rupr.) and white ash (F. americana L.). Specimens were collected and reared, and vouchers have been deposited in the Canadian Forest Service Arthropod Collection in Edmonton and the Canadian National Collection of Insects (CNC) in Ottawa, Ontario.

Production of sex pheromone was induced during the photophase, a time during which pheromone is not normally produced, in females of Heliothis virescens (F.) and H. subflexa (Gn.) by injection of homogenates and partially purified extracts of the brain – subesophageal ganglion complex of conspecific females or H. zea (Boddie) females or synthetic pheromone biosynthesis activating neuropeptide (PBAN). The amount of (Z)-11-hexadecenal, the major component of the pheromone of both species, increased during the first 60 min after injection of PBAN then leveled off and declined in H. virescens. In H. subflexa, the amount of this aldehyde increased during the first 120 min and declined after 240 min. Studies indicated that extracts of the brain – subesophageal ganglion complex that did not contain neurally produced biogenic amines induced production of as much pheromone as did homogenates containing these compounds. Dose-response studies indicated that the optimal dose of synthetic PBAN for induction of pheromone during a 60-min incubation was 5.0 pmol. In vivo maintenance of pheromone production required continuous stimulation of the pheromone gland.

Diel periodicities of emergence and oviposition of Trichoptera, observed in the St. Lawrence River at Montreal, Quebec (451/2° N.), in late June and July, are closely similar. They are poorly synchronized but the peak for most species is nocturnal, falling between sunset and solar midnight. Catches in floating traps were used to measure emergence rate. As such catches (of Trichoptera) may contain parous as well as newly emerged females, attempts were made to separate these two components of the catch before analysis, thus providing records for both emergence and oviposition. Oviposition periodicity was studied independently by counting egg-masses on a floating board. Precautions needed for future critical work on emergence are mentioned.

Population parameters of ectoparasites on feral pigeons, Columba livia Gmelin (Aves: Columbiformes: Columbidae), were estimated from 1995–2012 in southern Manitoba, Canada. The ectoparasites are chewing lice (Phthiraptera): Philopteridae – Campanulotes compar (Burmeister), Columbicola columbae (Linnaeus), and Coloceras tovornikae Tendeiro; Menoponidae – Hohorstiella lata (Piaget). We tested the hypotheses that both abundance and population stability are species-specific traits. Over 10 years, the four species of lice had distinct population dynamics. Campanulotes compar and C. columbae were more abundant than C. tovornikae and H. lata, had higher male to female sex ratios and higher ratios of nymphs to females, different levels of aggregation, and more stable populations. Campanulotes compar was more prevalent than C. columbae and its prevalence was more stable, and the two species also showed differences in the levels and stabilities of male and nymph to female ratios. Coloceras tovornikae had a higher prevalence and male to female sex ratio than H. lata, but the two species showed similar levels of stability for these parameters. The level of stability of these populations was relatively high compared with many other organisms, and in particular higher than for plant ectoparasites (Hemiptera: Aphididae). Although the four species occupy similar habitats, often on the same bird, and three of the four feed in a similar way, the population biology of each species is distinct. The life history traits that lead to these differences have yet to be determined.

Capric acid added to a food – whole wheat flour and dried brewers’ yeast – to constitute 2.5% or more of the foodstuff killed all Tribolium confusum Jacquelin du Val within 8 weeks. Lesser amounts of capric acid resulted in different degrees of mortality. By the end of 4 weeks similar results were inevitable when varied levels of capric acid were added to two representative dehydrated foods, tapioca pudding and macaroni and cheese. This uncustomary use of a long-recognized insecticidal fatty acid has some merit: for immixed with foodstuff it can control insect pests, and yet it, as a natural constituent of milk etc., is no stranger to metabolic systems of higher animals, so probably is not too hazardous to humans.

Diapause induction in Hyphantria cunea is under the joint control of photo-period, temperature, humidity, food quality, and possibly other variables, but insufficient data are available to permit a precise evaluation of their actions and interactions. Short daylength and low temperature induce diapause and the critical thresholds for New Brunswick – Nova Scotia populations are in the vicinity of 14.3 hours and 72°F, respectively. Low humidity increases the incidence of diapause, as does also the change in the nutritional quality of foliage late in the season. Both field data and the extrapolation of laboratory data to field conditions indicate that the occurrence of a partial second generation is unlikely in this area, even in warm seasons.

The distribution of feeding damage by adult Phyllotreta cruciferae (Goeze) was examined on the cotyledons, first true leaves, stems, and petioles of four crop species of Brassicaceae (Brassica juncea L. "Cutlass", B. napus L. "Westar", B. rapa L. "Tobin", and Sinapis alba L. "Ochre"). Previous studies showed that B. napus and B. rapa are susceptible, B. juncea is partially resistant, and S. alba is highly resistant to P. cruciferae. Flea beetles usually fed more on the upper surfaces, bases, and edges of cotyledons and first true leaves, but the feeding patterns were not identical on the four species. Phyllotreta cruciferae had a greater preference for the upper surface of S. alba cotyledons than for the upper surfaces of Brassica species. First true leaves of B. napus had over 90% of the feeding damage along the edge, compared with < 70% for the other species. The size of feeding pits did not differ on the upper and lower surfaces of the cotyledons and first true leaves for the Brassica species, but S. alba had smaller feeding pits on the lower surface. Sinapis alba also had the smallest feeding pits on the upper surface of its cotyledons, and S. alba and B. juncea first true leaves had feeding pits about one-half the size of the feeding pits on the other species. There was no significant difference in the amount of stem damage for the four species, but B. juncea had significantly less petiole damage than S. alba. Although there were differences in the way P. cruciferae exploited the seedling tissues of these Brassicaceae, the differences were not consistent with, or were too small to account for, the different levels of resistance of the four crops.