Six species of aphids belonging to four genera were measured for 12 morphological features at five developmental stages. It was concluded that reliable identification of species based on morphological features is possible only at adult stages. Samples were also analyzed for seven enzymes by gel electrophoresis. There were no enzyme pattern differences among developmental stages in any species. Three enzymes, malic dehydrogenase, malic enzyme and tetrazolium oxidase, showed the same band pattern in all species. The other four, acid phosphatase, alkaline phosphatase, esterase and leucine-alanine peptidase, showed “diagnostic” patterns specific to a given species. All species are easily identifiable by their esterase pattern which could be confirmed by acid phosphatase, alkaline phosphatase, and leucine-alanine peptidase patterns. The enzyme pattern differences were used to establish a dendrogram of genetic relationship among species which was compared with a dendrogram of morphological similarities. The close genetic similarity among species suggests that significant adaptive differentiation leading to speciation may have occurred within the context of relatively few genie changes. This is compatible with speciation in aphids being due primarily to their obligate parthenogenetic reproduction, frequent bottlenecks (drastic reduction in number), and host plant specificity.

A blacklight trap was established at 3790 m in 1978 and at 3505 m, 3657 m, 3790 m, and 3810 m, in 1979, on the alpine tundra in Colorado. Weekly catches from 6 July to 4 August 1978, and 26 June to 14 September 1979, resulted in ca. 3500 individuals of over 48 species of moths. These results establish that a greater diversity of moths exists and greater nocturnal flight activity occurs than was previously supposed for alpine tundra communities. The implications for pollination and insect foraging are discussed.

Percentage parasitism by seven insect parasites of the western spruce budworm, Choristoneura occidentalis Freeman, was not significantly different among crown aspects. Parasitism by two hymenopterous parasites was significantly different among crown levels in either one or both hosts. Other parasites were either insufficiently abundant to provide an adequate test, or percentage parasitism differed insignificantly among crown levels or host types. Because percentage parasitism was not generally different among crown levels, any level could have been sampled.

The developmental rates of individual larvae of Tribolium confusum Jacquelin duVal were measured at five temperatures on three diets to quantify the interaction between these two environmental factors. No significant differences in survival were detected but developmental times were affected by both factors. A logistic equation accurately described the relationship between mean developmental rate and temperature for each diet. The variance in developmental rate was a linear function of the mean developmental rate, and the mean accounted for more of the differences in variance than diet or temperature.

The effect of diet was greatest at the temperature which caused the highest developmental rate. It decreased as temperature decreased. This effect could be accounted for by varying the coefficient K, the asymptote of the logistic equation. The coefficient K showed a positive linear relationship to the lysine content of the diet. This coefficient may provide a compact and quantitative means of summarizing the interaction of environmental factors such as diet and temperature in the logistic model for the developmental rate of insects.

Previous work described the effects of predation of pea aphids by adult coccinellids. That work has been extended to cover the entire reproductive cycle of the coccinellids. The relationship between amount of aphids eaten, and numbers of coccinellid eggs produced, was determined in the laboratory and used to predict numbers of eggs produced in the field. The survival rate of the eggs to adults, as a function of aphid density, was estimated in large field cages and in small enclosures. These relationships were incorporated into a population model for both predators and prey. The model has been validated against field data. It suggests that predator reproduction is optimized when conditions are very good. The significance for optimal foraging theory and biological control is discussed.

Growth, development, and survival were investigated for the larvae of the red turnip beetle, Entomoscelis americana Brown, fed excised cotyledons or first true leaves of four cultivars of Brassica campestris L. (Torch, Echo, Candle, and R500) or three cultivars of B. napus L. (Midas, Target, and Tower) in the laboratory. The red turnip beetle has four larval instars and its growth curve is S-shaped. The seven cultivars of B. campestris and B. napus tested were suitable host plants for the larvae. On all the cultivars, survival was relatively high, the weights and developmental times were similar, and the percentage of malformed adults was low. In B. campestris and B. napus, the cotyledon stage was marginally better than the first true leaf stage as food for the larvae. Survival usually was higher and in one of the three experiments the adults at emergence were heavier on the cotyledons than on the first true leaves. However, the developmental times were similar, except in one of the three experiments where they were longer on the cotyledons, and the incidence of malformed adults was low on both stages of plant growth.

An apparatus consisting of a plastic box and a feeding circuit permits the calculation of μl volumes of ethanol ingested by Drosophila melanogaster Meigen. The net amount of ethanol taken (expressed in 100% ethanol) has been examined in various experimental conditions: sucrose solutions, ethanol–sucrose solutions at various sucrose and alcohol concentrations, ethanol solutions - cube of sucrose and ethanol solutions alone. The data obtained on ingestion by Drosophila show that the consumption of sucrose solutions was inversely proportional to the concentrations of sucrose. The amount of ethanol ingested during 14 days was directly related to the concentration of ethanol in the diets although in general the total volume of solution consumed did not vary significantly in most cases. The analyses of observations of 14 days showed that decreased mortality was obtained with the rise in the concentration of sucrose in sucrose-water solutions in 0.5–3% range and the mortality increased with the rise in the concentration of ethanol in the diets, yet ethanol-sucrose was better than cube of sugar alone.

All stages of a new genus, Euryhapsis, are described and differentiated from several other genera of primitive Orthocladiinae. Three new species are described: Euryhapsis cilium (type-species), Euryhapsis illoba, and Euryhapsis brevis. Eurycnemus annuliventris (Malloch) is transferred to Euryhapsis. A key to species of males is presented.

A serological technique, the precipitin test, was examined as a method for determining the feeding habits of the spider Pardosa sternalis Thorell (Araneae: Lycosidae). Radial immunodiffusion responses were significantly influenced by quantity of prey consumed, the time elapsed between spider feeding and serological analysis, and the temperature at which spiders were maintained after feeding. Maximum antigen detection time after feeding was 150–200 h for spiders fed varying quantities of prey and held at 25°C and over 400 h for those held at 4°C. Ouchterlony double diffusion tests indicated that although two congeneric prey species could be distinguished from one another, significant cross-reactivity between the two was observed. No such cross-reactivity occurred between more distantly related prey species. The feasibility for utilizing precipitin analyses in field studies of predator–prey relationships is discussed.

The behavior of adults of clerid beetle Thanasimus dubius (F.) preying upon adult southern pine beetles, Dendroctonus frontalis Zimmerman, in an arena in the laboratory is described by classifying the acts according to their consequences. A sequence of five stereotyped acts is performed by the predator: either searching or ambush, seizure of prey, alignment of prey, consumption of prey, and grooming. Handling time by the predator consists of the sums of the durations of the four acts of seizure through grooming, which was not significantly different for male and female predators, but was significantly longer for male prey (13.81 min) than for female prey (10.49 min). Consumption of prey (8–9 min) is the major component of handling time. Predators searched or waited in ambush an average of 5.8 mm before seizing a prey, and captured prey with an efficiency of 72%. Blinding predators had no significant effect on their efficiency at capturing prey. Maxillary and labial palpectomy alone or in combination significantly reduced efficiency of capture, and reduced numbers of prey consumed.

The life history of Plutella xylostella (L.) was studied in plantings of Brussels sprouts at Cambridge, Ontario in 1977 and 1978. Adults were monitored by using sticky traps constructed of bristol board; eggs, larvae, and pupae were monitored by sampling plants. In both years in the spring, some of the first eggs were found before adults were caught in the traps. The trap collections indicated four periods of adult flight each year. During the last period of flight in 1977 eggs were laid; however, the fifth generation was not completed. Day-degree analyses of the populations indicated that 293 day-degrees (C) above a threshold temperature (7.3°C) were required to complete one generation. Using day-degree accumulations it was possible to predict accurately the periods when various stages of the pest were dominant even though there was considerable overlap of various stages in the field.

Nine species are recognized, of which six are new to science: Teleas crassifemur ♂, T. neptuni ♀ ♂, T. niger ♂, T. punctifrons ♀ ♂, T. terricola ♀, and T. villus ♂. The three previously described species which are retained in the genus Teleas, viz. T. lineaticeps Ashmead, T. pallidipes Ashmead and T. sibiricus Kieffer, are redescribed. Females of T. lineaticeps and T. pallidipes are described for the first time. All other Nearctic species listed by Muesebeck (1979) under Teleas are presently transferred to the genus Trimorus Foerster (subfam. Teleasinae) (all new combinations): Trimorus americanus (Ashmead), T. coxalis (Ashmead), T. harringtoni nom. nov. (= Teleas canadensis Harrington nec Acolus canadensis Ashmead), and T. mandibularis (Ashmead). T. sibiricus Kieffer is the only member of the genus known to have Holarctic distribution.

A key to the females and males of Nearctic Teleas and a key to Nearctic genera of Teleasinae are presented.

The multiporous plate sensillum occurs on the antennae of Hymenoptera. The internal and external cuticular surfaces of these sensilla, as well as the cellular ultrastructure, were examined in the Braconidae by electron microscopy. The sensillum has an elongated, external, porous plate and an inner, cuticular septum in which there is an aperture. It is innervated by numerous neurons, the dendrites of which pass through the aperture, branch and traverse the longitudinal axis of the sensillum. The ratio of aperture length to sensillar length was measured on the internal cuticular surface in 32 species. This ratio increased from the ancestral to the derived species. This sensillar character may be useful in elucidating braconid systematics. It also has potential use in the systematics of other hymenopterous parasitoids.

Hunger and abundance of adult Coccinella californica (Mannerheirn) preying on pea aphids, Acyrthosiphon pisum (Harris), on alfalfa, Medicago sativa L., were assessed in the field. There was no consistent relationship between abundance or hunger and aphid density. The field beetles encountered in sampling were 4 times hungrier at each observed aphid density than expected from a simulation model of the predation that is driven by hunger. Laboratory studies revealed a circadian rhythm of beetle activity that was modified by hunger. An index of predatory potential (number of beetles times average hunger) was found to be a better indicator of impact of the beetles than absolute numbers of all coccinellids or hunger separately. It is suggested that the beetles encountered in simply walking through a field produce the most useful index of numbers of hungry beetles. This census must be done daily however because of the high vagility of adult coccinellids.

The genus Thripoctenoides (subfamily Entedontinae: Eulophidae) is recorded from North America for the first time, and Thripoctenoides kaulbarsi, new species, is described.

Three colonies of Polistes fuscatus (Fabricius), each with two foundresses, were bisected during the pre-emergence stage and separated for 20 days. In the absence of the dominant, each subordinate foundrss became an egg-laying queen on her half of the nest. The dominant foundress did not exhibit superior reproductive productivity. The split colonies were reunited by placing the nests approximately 4.0 cm apart in a single nest box. Each foundress and all workers were observed tending both half-colonies, and the original dominance hierarchy was apparently restored in two of the three colonies.

The wheat bulb fly, Delia coarctata (Fallén), a widespread Eurasian species, is recorded for the first time from Quebec, New Brunswick, Prince Edward Island, Nova Scotia, and Maine. Unlike most Anthomyiidae, this species overwinters in the egg stage in the soil. Hatching occurs in early spring, and young larvae attack the roots of fall-germinated grasses. The primary host is couch grass, Agropyron repens (Linnaeus). In Europe, however, D. coarctata is an important pest of winter wheat, and workers in North America are alerted to its potential economic importance here. Adults may be distinguished from other root maggot flies by a combination of characters which includes the plumosity of the arista, the setation of the thorax and legs, the colour of the wings and legs, and most importantly, the details of the male and female terminalia.

Seasonal emergence, abundance, biting and oviposition activity of Mansonia perturbans (Walker) were monitored in southwestern Ontario during 1977 and 1978. Adults emerged from 13 June until 24 August with the greatest emergence occurring in mid-June and mid-July. In both 1977 and 1978, adults were collected by dry ice-baited CDC light traps from 7 June until at least 7 September, with a peak of abundance in late June, followed by a smaller second peak in early August. Biting activity occurred from the second week of June until the first week in September with a maximum during the last week of June. Oviposition occurred from 30 June until 24 August with a maximum in early July.

A new spray application system which mimics the spray deposit of aerial applications of chemical insecticides was developed and tested using acephate at the rate of 60 g a.i./L (U.S. Environmental Protection Act registered dosage) on small Douglas-fir and subalpine fir trees infested with western spruce budworm. The system successfully duplicated aerial application by causing a budworm population reduction equivalent to previous aerial tests having analogous insecticide deposit characteristics. Using the system, preliminary information was gained on the effectiveness of sulprofos and thiodicarb. When delivered at a rate of 4.1 L/ha, sulprofos caused a budworm population reduction of 86.2% at 22.4 g a.i./L and thiodicarb caused a reduction of 98% at 45 g a.i./L.

The suitability of nine species of Cruciferae as hosts for the larvae of the red turnip beetle, Entomoscelis americana Brown, was tested in the laboratory using excised cotyledons or true leaves as food and rape (Brassica campestris L.) as the standard. The three types of commercial mustards grown in Canada (yellow-seeded (oriental mustard) and brown-seeded (brown mustard) forms of Brassica juncea (L.) Czern.; and yellow mustard, B. hirta Moench) and three weeds (Capsella bursa-pastoris (L.) Medic, shepherd’s purse; Erucastrum gallicum (Willd.) O.E. Schulz, dog mustard; and Sinapis arvensis L., wild mustard) were suitable food plants. Brassica nigra (L.) Koch (black mustard), Descurainia sophia (L.) Webb (flixweed), and Sisymbrium loeselii L. (tall hedge mustard) were marginally suitable. Thlaspi arvense L. (stinkweed) was a non-host plant. These observations suggest that an important element of the pest management system for the red turnip beetle should be the elimination of volunteer commercial mustards and the cruciferous weeds, except T. arvense, in April and May to prevent population build-up.