Culex pipiens (L.) and Culex restuans Theo. populations were monitored at Guelph, Ontario, throughout the summer of 1978, by egg raft collections from artificial pools and adult collections using CO2-baited, CDC light traps. Three to four major generations of C. pipiens were evident with first oviposition on 17 May and last on 15 October. C. restuans was abundant during the spring and early summer while C. pipiens was most abundant in mid-July and August. Neither species showed greater attraction to pools containing a reported ovipositional attractant, decanoic acid. The use of oviposition pools was found to be an efficient, inexpensive, and sensitive technique for monitoring populations of Culex spp.

Mature Telrastichus julis (Walker) larvae, which overwinter in the pupal cells of their dead cereal leaf beetle hosts, enter diapause in late summer. Diapause is maintained by warm conditions and short daylengths during late fall and early winter; it ends without a specific terminating stimulus. Subsequently the larvae remain in a state of postdiapause quiescence until soil temperatures rise above 9 °C, the theoretical threshold (t) for postdiapause development. Emergence of the central New York population occurs when the parasites have accumulated 162 degree days (D°) of heat above 9 °C. This K value is considerably lower than that previously reported for a population from Michigan.

Our study provides the first experimental evidence that both temperature and photoperiod regulate the rate of diapause development in a parasitic insect.

Because little is known of the pre-settlement insect fauna of Canada it is now almost impossible to assess all of the changes that have been caused by settlement. For most of the time that has elapsed since colonization began, settlements have been small and scattered, and land use has been non-intensive. Many refuges for native insects persisted until very recently, and many still persist but are diminishing. Thus probably few aboriginal species have been driven to extinction. Many ruderal and cultivated plants accompanied settlers from Europe and Asia. Some of these provide an expanded food supply for a few native insects and these have expanded their numbers and ranges. Other native insects have been displaced and diminished by depletion of forests and planting of crops. Exotic plants are inevitably accompanied by exotic insects and Canada has provided a hospitable home for a multitude of exotic insects. Over 300 species have been deliberately introduced for biological control.

Once established in a colonial environment, the exotic origins of immigrant species are difficult to detect. Seven criteria for detecting exotic insect populations are suggested.

The impacts of settlement on the principal geographic regions of Canada and their probable influence on insect faunas are briefly discussed.

It is concluded that the insect fauna of Canada has been greatly enhanced by settlement.

The effect on stream invertebrates of carbaryl (Sevin-4-oil®) applied at a rate of 840 g A.I./ha for spruce budworm suppression in Maine was studied. Three streams in each of three different treatment areas were monitored: streams in areas sprayed with carbaryl for the first time, streams in areas sprayed 2 consecutive years, and streams in unsprayed areas.

Initial postspray response was an increase in drift up to 170× in treated streams. Benthos samples showed significant declines among Plecoptera, Ephemeroptera, and Trichoptera on subsequent sampling dates. Plecoptera did not repopulate any treated stream by 60 days after treatment. Streams treated for the second consecutive year had very low prespray Plecoptera populations compared with those unexposed to carbaryl. Diptera, with the exception of Microtendipes, and Oligochaeta were unaffected.

Habitats and life cycles of five species of water striders were compared in south-central British Columbia. Three species of Gerris were bivoltine; both Limnoporus species were univoltine. Generation timing varied markedly among lakes and periods of maximum abundance for all species overlapped. Each species showed distinct association with a single type of habitat defined by vegetation structure. These associations separate most species among lakes and suggest that habitat is the most important resource axis for ecological separation of gerrid species on the Fraser Plateau.

Five syntypes of Calotelea ocularis Ashmead were studied; a lectotype is selected and redescribed. The ocularis-species group of Calotelea is proposed. The history of the type material of Caribbean species of Proctotrupoidea treated by Ashmead (in Riley et al. 1894) is briefly discussed.

In 1976 and 1977, adults of Aedes sticticus (Meigen) and Aedes vexans (Meigen), marked with fluorescent dust, were captured in light traps up to 33 days after release and at distances up to 11 km from the release site. Adults flew primarily northwest from the release sites, and with the prevailing winds. Porcine and bovine hosts present at some of the trapping sites, appeared to be highly attractive to female mosquitoes. Within an 8 km trapping radius of the release site, the mean number of marked/trapped female mosquitoes decreased with distance. In 1977, 50% of the marked captures (weighted according to km2 of trapping area) were taken within the first 2 km, 82% within 4 km, 92% within 6 km, and the remainder out to 8 km from the release site. For all trap sites, the mean recovery of marked/unmarked adults over a 33 day trapping period in 1977 was 1:1113.

Five red-winged blackbird nests were collected from Delta Marsh, Manitoba in June 1975 and examined for insect fauna. Three nests were examined in October 1975, and one in June 1976 for Siphonaptera and Calliphoridae. Two thousand five hundred and forty arthropod specimens of 68 insect species and a few undetermined species of Acarina were recovered. Of the insects, 65.5% were Diptera, 27.6% were Coleoptera, and the remainder were from six other orders. Blood feeding forms included Culicoides crepuscularis (Diptera) and Ceratophyllus garei (Siphonaptera). The fauna of these wet nests differed qualitatively and quantitatively from dry nests studied by others.

Populations of flying potato aphids (Macrosiphum euphorbiae (Thomas)), available to initiate new infestations on crops, were measured by plant trapping from 1966 to 1971 and by suction trapping from 1967 to 1978 at Harrow, Ontario. Yearly total catches were extremely variable and in some years there were periods of 2 weeks without catches during the summer. The long term annual flight pattern was a unimodal curve with a peak in August. Counts by plant trapping correlated with those obtained by suction trapping, and catches on Brussels sprouts, tomatoes, and peppers were all positively correlated. Plants exposed on a background of bare soil attracted more alatae than those exposed on a background of mowed weeds. The first female alatae were caught in the suction traps on 21 June ± 5 days each year and the first male alatae on 22 October ± 2 days. The last female alatae were caught on 21 October ± 5 days and the last males on 6 November ± 2 days.

The pattern of blood feeding in males of Stomoxys calcitrans L. is different from that of females. Female flies ingest more blood than males. Females fed only blood or blood and sugar-water ad libitum showed a periodic pattern of blood ingestion. The amount of blood ingested at the time of first feeding is partly dependent upon the age of the flies; in addition flies fed only blood ingest more than flies whose blood diet is supplemented with sugar-water. During the period prior to blood feeding the weight loss per day increased as the fly aged. On the other hand if the flies were fed with sugar-water from the time of emergence they gained considerable weight. The rate of weight loss after one blood meal was of the same pattern in flies fed 24 or 48 h after emergence. The pattern of weight loss was also similar in flies fed sugar-water ad libitum and blood 24 h after emergence.

Pieris callidice from the French Alps was hybridized with the phenotypically similar P. occidentalis nelsoni from Fairbanks, Alaska in order to examine the degree of genetic divergence within a group of Pleistocene origin. Egg hatch for the cross nelsoni male × callidice female was zero. In the reciprocal cross, egg hatch was normal, but most of the larvae failed to feed on the normal host-plant of nelsoni, and died. The hybrid pupae and the single adult were intermediate between the parents. It is inferred that P. callidice and P. o. nelsoni are more divergent genetically and physiologically than phenotypically.

The relationship between body size and age in two species of Collembola, Folsomia Candida and Xenylla grisea, was studied in three temperature regimes. Power curves were used to describe length as a function of age for each species-temperature combination. Growth parameters (slopes of the log-log curves) and length at hatch (log intercepts) were compared by multiple regression. There was a strong non-linear effect of temperature on growth in the range normally encountered.

The first detailed morphological description of the last-instar larva of Zophodia convolutella (Hübner) is presented. The life history, distribution, and economic importance are discussed.

A number of ketocatechols have been isolated and identified from acid hydrolysates of larval and pupal exuviae of the spruce budworm, Choristoneura fumiferana. The most abundant of these, 2-hydroxy-3′,4′-dihydroxyacetophenone, represented 5.8% of the dry weight of pupal exuviae, 4.6% of larval head capsules, and 0.3% of the remaining larval exuvium. This compound is thought to be the primary breakdown product arising from crosslinks between cuticular proteins and the aliphatic sidechain of a phenolic tanning compound. The yields therefore reflect the extent of β-sclerotization, one of two mechanisms proposed for the hardening of insect cuticle. Budworm is similar to other species with respect to the types of hydrolysis products recovered although three previously undescribed compounds were detected.

An assessment of toxicological responses among the Choristoneura species occidentalis, viridis, and fumiferana indicated that within-species variation in response to acephate may be as large as between-species variation. Studies of C. occidentalis sibling groups suggest that allozyme variation at the second esterase locus may be related to differential sensitivity to acephate. Use of genetic markers to forecast population response in control programs is discussed.

The rise and decline of two infestations of Aphis barberae Robinson on the thistle Cirsium arvense (L.) Scop, are described. The larger infestation consisted of 122 colonies in an area 8 m in diameter and produced many alatae before declining. The second infestation consisted of 12 colonies and produced no alatae. Each infestation appeared to arise from a single central colony and spread when alate and apterous aphids travelled short distances to adjacent plants. The growth patterns indicate that each infestation represented a single clone. Both infestations declined rapidly due largely to predation and became locally extinct early in the summer.

Strategies for the use of entomopathogenic viruses in the management of forest insect pests include the use of viruses by themselves or with other biocontrol or chemical agents applied simultaneously or separately at strategic time intervals. It is concluded that baculoviruses (nuclear polyhedrosis and granulosis viruses) have considerable potential as components of integrated forest insect pest management systems. The prime limiting factors in their large scale use at present are the high cost of virus production and underdevelopment of application technology. Their greatest potential will probably be realized when used as an indirect, or preventative, strategy with a view to preventing the occurrence of pest emergency situations.

The aquatic plants Utricularia minor L., Lemna minor L., and Elodea canadensis Rich. in Michx. were tested for their effects on the colonization of artificial ponds by mosquitoes and their predators. During the 11 weeks of sampling there were significantly fewer mosquito eggs, and hence mosquito larvae, in the plant-filled ponds than in plantless control ponds, and more predators in the Utricularia and Elodea ponds than in the plantless and Lemna ponds.

A convenient and efficient method of determining if qualitative changes are associated with changes in density of insect populations is to search for changes in isozyme frequencies (Stock and Guenther 1979). However, obtaining sufficient material for analysis of low density populations presents a problem. We have found that the use of sticky traps baited with synthetic pheromone is an efficient and practical method of surmounting this problem.

Morphological interpretations are given of sclerotized areas, such as the prothoracic shield, anal plate, and pinacula of lepidopterous larvae. Markings of these sclerotized areas which indicate the positions of muscle attachments are classified; new systematic names are suggested based on those of the corresponding muscles. The importance of sclerotized areas and markings for larval classification are shown by examples. These markings are used to distinguish certain closely related species of the genus Chilo (Pyralidae).