Eleven species of the family Cixiidae have been recorded from Canada (Metcalf, 1936, Gen. Cat. Hemip. 4 (2)). Ten of these are represented in the Canadian National Collection. In addition, ten other species are represented by Canadian specimens. Three of these are previously undescribed. The following are descriptions of the new species, keys to the genera and species known to occur in Canada, and distributional notes on the species from specimens in the collection. External characters are used in the keys. These are not always reliable in determining the males of some closely allied species, because of the frequent absence of dark elytral markings in that sex. The male genitalia show good specific characters, and figures of these are given for the species difficult to determine reliably an external characters.

Although DDT gives excellent control of the striped cucumber beetle, Acalymma vittata (F.), the most serious insect pest of cucumbers in Canada, the technical grade of DDT is generally considered too toxic to cucumbers to he used on that crop with safety. Recently, two related materials that are said to be less toxic to cucurbits in general have been on the market: high-setting-point DDT, and methoxychlor. Carruth and Howe (1948) showed that DDT approaching aerosol grade in setting-point was less injurious to squashes than DDT of technical grade. Several entomologists have reported that cucumbers, like melons and squashes, show definite varietal responses to DDT. Hervey and Schroeder (1946) found the variety Ohio 31 to be more severely injured by DDT than China or Chicago Pickling. Wilson and Sleesman (1947) reported that plants of Ohio 31 were stunted much more by DDT than those of National. This paper is a report on three seasons' investigations of the toxicity of three per cent technical-grade DDT dust to 12 varieties of cucumbers, and one season's investigations of the toxicity of three per cent high-setting-point DDT and methoxychlor dusts to the same 12 varieties.

Grasshoppers, tree crickets, and katydids always cause some injury to tobacco in southwestern Ontario, and at times the injury is very severe. Thc leaves may be riddled or even completely stripped, the most severe injury usually occurring late in the season, about harvest time. These insects breed in sod, in wood-lots, and along roadsides, and such areas require special attention when control measures are undertaken. Because it is usually considered advisable to restrict the amount of insecticide applied to tobacco leaves, the chlordane dust used in this experiment was applied only to the vegetation bordering the field. Any control by applying poison to tobacco plants can be effected only after at least limited feeding and some injury to the leaves; but treatment of field margins uses waste plans as the poison ‘carriers’ and a large part of the injury to tobacco is avoided. This method of control is useful only for insects which feed on general vegetation and would be of little value in controlling species which restrict their feeding to the cultivated crop.

A large apple orchard at Queenston, Ont., was sprayed regularly with DDT in 1946, 1947, and 1948, but in 1949 part of it was left unsprayed. The unsprayed trees became so heavily infestcd with leafhoppers that by the end of August the foliage was severely injured. The injury was similar to that caused by the white apple leafhopper, Typhlocyba pomaria McAtee.

A collection of more than 200 nymphs was made on August 11 and reared to maturity, and additional adults were collected on August 29. All of the males, except a few specimens of Erythroneura lawsoniana Baker, proved to be Typhlocyba froggatti Baker.