The data presented in this paper were obtained during preliminary tests of acaricides that have been carried on in the greenhouse since 1947. Special attention has been given to the duration of residual action because this is one of the most critical indications of the potential value of an acaricide under field conditions. Residual toxicity in these experiments may he defined as the toxicity of a dry deposit to mites introduced on foliage subsequent to spraying.

The modes of action of the various acaricides are uncertain. In most cases it is undoubtedly contact action, although the more volatile materials may have some fumigant effect. Toxicity by direct ingestion is unlikely because of the feeding habits of the mites, but it is possible that some of the compounds tested may have a systemic action, being absorbed by the plant and remaining within the tissues for an extended period.

Aggregations of various species of spring-tails on the surface of the snow have been noted and reported upon by several authors. Of these species, the one occurring most commonly is Achorutes socialis Uzel (Podura nivicola Fitch) which Folsom (1916) records as being a common species in most parts of Europe and occurring in several localities in the north-eastern United States. MacNamara (1919b) studied the habits of this species as it appeared in the vicinity of Arnprior, Ontario, reporting that it “may be as thick as 500 to the square foot, while in hollows and depressions in the snow—such as foot-prints—from which they cannot escape, they sometimes accumulate in solid masses that could be ladled out with a spoon.” James (1933) noted an assemblage of this species at Pottageville, Ontario, and reported that “beneath the hemlocks they covered the snow with a frequency of over 400 to the square foot.” A related species, tentatively identified as A. bengtssoni Agren, appeared in a population estimated by Park (1949) as exceeding 4,000,000 from three exit holes in an area of six square feet in Illinois in December, 1946.

The following article contains two records apparently new to Vancouver Island, notes concerning two species rare in collections from the island and remarks concerning the status of Leptura soror LeConte.

Holopleura murginata LeC. A single male, taken on Mount Tzouhalem, Duncan, Vancouver Island, on May 21, 1947, by R. L. Fiddick apparently provides the first record for the island. This interesting species was called to my attention by G. Stace Smith of Creston to whom it was originally sent for determination. The only other British Columbia record, published by H. B. Leech (1945) is based on a single specimen beaten from a Douglas fir at Arrowhead, B.C. by G. Slade on May 10, 1945.