The Forest Insect Survey of the Maritime Provinces has been observing an outbreak of the winter moth, Operophtera brumata (Linn.), since its discovery in Nova Scotia in 1949. In addition to noting annual changes in distribution, the Survey has made population counts on 8 to 20 tagged trees of red oak, Quercus rubra L., at each of seven locations along the south shore of the Province. These trees were sampled each year to show the abundance of larvae of the winter moth and the fall cankerworm, Alsophila pometaria (Harr.). Both species are commonly found on the same trees, and their life histories are similar. The collections and subsequent rearings also showed the degree of parasitism by native or introduced species of parasites. The defoliation of the trees was estimated at the time of sampling and again at the end of the feeding period to determine the relationship between larval population and defoliation. Some of the sampling data, which were collected from 1952 to 1955, are used to develap the sequential plan of sampling described herein. Use of the plan at the sampling stations should reduce the number of samples while retaining accuracy within predetermined limits.

In this paper 12 new species and a new genus (Prochramesus) of scolytid beetles are described from Mexico, and one species is described from Honduras. Notes concerning geographical distributions of a few other Mexican species are included. The specimens taken in Mexico were all collected by the author while with the 1953 expedition of the Francis Huntington Snow Entomological Museum (University of Kansas, Lawrence). The new species represent the following genera: Pseudohylesinus (1), Phrixisoma (1), Leperisinus (1), Phloeosinus (1), Chaetophloeus (1), Renocis (1), Phloeotribus (1), Prochramesus (1), and Chramesus (4).

When working with the stereoscopic microscope it is often desirable to use both hands for continuous manipulation of dissecting instruments or material under observation. In many instances, however, as when using the higher magnifications to study internal organs of insects, repeated focus adjustments are needed. The use of one hand for focus control is then a source of inefficiency and annoyance because it means frequent change of an instrument from its carefully adjusted position in the microscope field. Eyestrain and unsatisfactory performance follow attempts to reduce the number of adiustments made.

Aedes melanimon was described by Dyar (1924) from specimens collected at Bakersfield, California, as closely resembling Aedes dorsalis (Meigen) but differing in color, wing-scale pattern, and in the male genitalia. Freeborn (1926) considered A. melanimon to be an “aberrant form” or “race” of A. dorsalis. Two species closely related to A. dorsalis are the American Aedes campestris Dyar and Knab, and Aedes caspius (Pallas) of Europe, Asia, and Africa.

House fly control as practiced at present requires a combination of thorough sanitation supplemented with the use of insecticides. Farms vary considerably in the standard of sanitation maintained. The question arises whether a farmer who conscientiously applies house fly control measures on his premises will find his efforts frustrated by invasions of house flies breeding on less sanitary farm-steads in the neighborhood. To answer this question it is necessary to understand the factors that affect house fly dispersal. These include wind direction, intensity of mind-borne odors and possibly variation in the tendency of flies to migrate. Some of these questions were answered in investigations during the summer of 3951, by releasing and recovering radioactive house flies in a dairy community near Fort Whyte, Manitoba.

The introduction of predators of the balsam woolly aphid, Adelges piceae (Ratz.), from Europe to the Atlantic Provinces of Canada was commenced in 1933 as a joint project of the Forest Biology and Entomology Divisions of Science Service and the Commonwealth Institute of Biological Control. Several species were released between 1933 and 1941 but only one, Neoleucopis obscura (Hal.), became established and its control value was insufficient (Balch, 1952). The project was continued in 1951 and several additional species have been established. Studies of these predators and their place in the control complex in Canada were undertaken and this paper is the first in a series on the subiect. It results from the necessity of rapid field identification of the various stages of all predators found. It deals with three closely related dipterous predators, two of which were introduced, N. obscura and Cremifania nigrocellulata Cz., the other, Leucopina americana (Mall.), being native to Canada. Similar descriptions of the other species with a key will be published later.

During spray trials carried out recently for European pine shoot moth control in Ontario, a method was developed to assess dyed, oil-based insecticide spray deposits colorimetrically using a paper sampling surface. The procedure permits intensive sampling without the necessity of handling fragile or bulky sampling kits in the field.

Bacillus sotto Ishiwata is a bacterial pathogen of the larvae of Bombyx mori L. (the silkworm) and it has been shown (2) that the toxin it produces is associated with the crystalline inclusions (5) found in sporulated cells of this microorganism. The pathogenicity of B. sotto for the larvae of certain insect species and the properties of B. sotto toxin have been described previously (1, 2, 3). In the present paper the effect of the toxin on the larvae of several insect species is reported.