As part of a St. Louis Encephalitis Surveillance Program adult mosquitoes were collected weekly from May to September, 1976–1978 with dry ice-baited traps at 11 sites in four areas of southwestern Ontario. Thirty-four species from six genera were caught but of the 210,000 mosquitoes collected, three species, Mansonia perturbans (Walker), Aedes vexans (Meigen), and Culex pipiens Linnaeus (including C. restuans Theobald) comprised more than 90% of the catch. The greatest number of species were collected in June and July. The greatest number of mosquitoes were captured in July as the three principal species were most abundant at this time. The seasonal distributions of the nine most common species are presented and explanations suggested for the patterns of some of these. This study confirms and extends the findings of previous mosquito surveys in southwestern Ontario and should provide useful information for future programs on mosquito research and control in this region. Based on its seasonal pattern, relative abundance, SLE virus isolations and its record as an efficient vector in the USA, C. pipiens is probably an important vector of SLE in southwestern Ontario.

The generic classification of the Macropsini is reviewed, and five new genera and four new subgenera are erected: Macropsella n. gen., Macropsis (Neomacropsis) n. subgen, M. (Parapediopsis) n. subgen., Pedionis n. gen., P. (Thyia) n. subgen., Pediopsoides (Celopsis) n. subgen.; Reticopsis n. gen., Toropsis n. gen., and Varicopsella n. gen.. The following genus-group names are considered to be subgenera: Macropsidius Ribaut as a subgenus of Macropsis Lewis; Nanopsis Freytag, Kiamoncopsis Linnavuori and Sispocnis Anufriev as subgenera of Pediopsoides Matsumura; Parasitades Singh-Pruthi as a subgenus of Oncopsis Burmeister. Asmaropsis Linnavuori is synonymized with Hephathus Ribaut, Tsavopsis Linnavuori is synonymized with Macropsis (s.s.) Lewis, and Zinneca Amyot & Serville is synonymized with Oncopsis Burm. (s.s.).

Three hundred and seventy-three macropsine species (including 59 unnamed species) are placed generically, with 73 new combinations. Twelve new species are described: Macropsella complicata (New Guinea), Macropsis citronella (Australia), M. gagnei (New Guinea), M. gressitti (New Guinea), Oncopsis enopis (Nepal), O. nepalensis (Nepal), O. tortosa (Nepal), Pedionis astrala (Philippines), P. contrasta (Hong Kong), P. venosa (Japan), Pediopsis femorata (Formosa), Varicopsella obtusa (Borneo). An index is provided to the 436 available names in the Macropsini, including four unplaced species from the Ethiopian region and 21 from the Australian region.

Macropsine types in the B.P. Bishop Museum, Honolulu, the British Museum (Natural History), London, Hokkaido University, Sapporo, Japan, and the U.S. National Museum, Washington are illustrated and lectotypes are designated for Kirkaldy and Matsumura species. A neotype in the Canadian National Collection is designated for Zinneca flavidorsum Amyot & Serville.

The female of Xysticus winnipegensis Turnbull et al., 1965 is described for the first time. The external genitalia of the female show the species to belong to the luctuosus group of the genus rather than the triangulosus group as previously supposed.

The genus Carphacis des Gozis (Staphylinidae: Tachyporinae) is revised and recognized as a valid genus rather than a subgenus of Lordithon Thomson (= Bolitobius auctorum). Three species, dimidiatus Erichson, intrusus Horn, and nepigonensis Bernhauer are recognized as valid and transferred from Lordithon to Carphacis. Bolitobius dimidiatus humeralis Melsheimer is considered a new synonym of C. dimidiatus, and B. ruber Malkin and B. intrusus wallisi Malkin are considered new synonyms of C. nepigonensis. All taxa are described and illustrated and maps showing the known distribution of each species are included. A key is presented to aid in distinguishing the North American and only known Palearctic species.

A key is given to nine species of Macrosiphum (Sitobion) on ferns in North America, including four new species: M. (S.) lambi new species from Athyrium filix-femina (L.) Roth, in Algonquin Park, Ontario; M. (S.) woodsiae new species from Woodsia ilvensis (L.) R. Br., Manitoba and Northwest Territories; M. (S.) clydesmithi new species from "bracken fern" (Pteridium aquilinum (L.) Kuhn), Utah and Oregon; and M. (S.) walkeri new species from Nephrolepis exaltata (L.) Schott., Arcadia, California.

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.

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.

The chemical composition of plants is one of the major factors influencing their acceptability as food by insects. The interrelationships among these chemicals and between them and insect predators is very complex (Davis 1968). Some are inherently toxic to insects (Singleton and Kratzer 1969); others inhibit feeding (Hsiao and Fraenkel 1968); and still others act both as toxicants and as repellents (Bennett 1965). Apparently, no class of chemical compound is without representation in this regard.

The Colorado potato beetle, Leptinotarsa decemlineata (Say), is distributed throughout the world and is an occasional pest of potatoes in Atlantic Canada. During the course of rearing Colorado potato beetles for behavioral studies at the Fredericton Research Station I obtained a strain of beetles which differs from the normal brown morph in being predominantly white. Similar coloring occurs in larvae and pupae and in young female and male adults. The eggs are light yellow instead of the usual orange-yellow. Such an albinic mutant has been previously reported in the United States by Tower (1906) and named L. pallida. Tower found the white mutant to be true-breeding and widely distributed, occurring both in nature and in laboratory colonies. Such a mutant has not been reported since and this is the first record of a white morph in Canada.