A great number of papers and notes have been written on the root maggots attacking cabbage, cauliflower, turnip, and radish in Canada and the United States during the past 75 years. These deal chiefly with the occurrence, life-history, and control of the cabbage maggot, Hylemya brassicae (Bouché), or species which have been misidentified as that species. The Canadian work has followed the lead of Gibson and Treherne (1916), but in spite of the accumulation of information on the life-history of the species, on cultivation methods, and on insecticides, the pests of these cruciferous plants remain as noxious as ever.

This paper offers a taxonomic treatment of the American species belonging to the genus properly known as Phratora but designated as Phyllodecta Kby. by recent authors. Phyllodecta was described by Kirby in 1837 (p. 216); the month of publication is given as October by Sherborn (1929, p. 4931), and, according to Westwood (1837). Kirby's volume was presented on November 6 to the monthly meeting of the Entomological Society of London. Phratora has been attributed to Redtenbacher, because he was the first to publish the name with a description of generic characters, and has been dated 1845 (p. 116) or 1849 (p. 554). Phratora Redt., lacking priority, has been considered a synonym of Phyllodecta Kby. However, in 1837 both Chevrolat (p. 405 or 429) and Faldermann (p. 363) used Phratora in ways that would validate the name; Chevrolat's usage, and possibly that of Faldermann, antedates Kirby's description of Phyllodecta. Chevrolat listed previously described species Phratora, and his usage, as shown by Barber and Bridwell (1940, p. 4), was published between March 1 and July 5, 1837. Faldermann, without comment on the genus, described a new species in Phratora, but the exact date of his publication is unknown. The species considered by all these authors are congeneric. A consideration of genotypes is impractical at this time, but such is not required to show that the genus should be known as Phratora and that Phyllodecta is a synonym.

The parasitism of the yellow-headed spruce sawfly, Pikonema alaskensis (Roh.), was studied in the course of investigations on the control of the sawfly in farm shelter-belts. Although some of the chemical control measures used against the sawfly destroyed its parasites, others did not. A knowledge of the parasites and their abundance in the study area became necessary. Since most of the parasites known to attack the sawfly emerge from the cocoons, this stage of the host was investigated first.

In the laboratory culture of parasitic Hymenoptera it is a common practice to collect the adults from the large emergence cages into glass tubing with a power-driven aspirator. This glass tubing has an absorbent cotton plug at one end and the aspirator cork at the other. Depending upon the characteristics of the species being handled, from 100 to 400 individuals may be collected without impairment into a single tube before the aspirator cork is removed and replaced with another plug of absorbent cotton. The cotton plugs are then tightly fitted into each end of the tubing, and the volume of air space remaining between them amounts to approximately 38 ml. Parasites confined in this manner may be stored for brief periods if fed honey and held at cool temperatures. They are commonly packed in this fashion for transport to experimental field plots.