In the apple orchards of Nova Scotia DDT, azinphos-methyl or lead arsenate control the winter moth, Operophtera brumata (L.). DDT, even at a low dosage, is detrimental to predators but not to the phytophagous mites Bryobia arborea M. & A. and Panonychus ulmi (Koch); azinphos-methyl is toxic to B. arborea but not to P. ulmi; lead arsenate is of low toxicity to both the phytophagous mites and predators but effective in control of the winter moth when applied against the maturing larvae.

The first record of the occurrence in Canada of the pear fruit sawfly, Hoplocampa brevis (Klug), was made on 2 June 1964 when several larvae were collected in pear fruits near Queenston, Ontario, about one mile west of the Niagara River. The identity of the species was confirmed 26 May 1965 by Dr. H. E. Milliron, Taxonomic Section, Entomology Research Institute, Canada Department of Agriculture, Ottawa, from three adult sawflies taken in pear orchards 12–19 May 1965 and one adult that emerged in a cage 17 May 1965 from an overwintered larva.

The westermanni group of the genus Euxoa is defined, and a key to the eleven constituent North American species is presented. Two species are described as new: chimoensis from Fort Chimo, Quebec, and luteomaculata from montane areas of southern Alberta, southern British Columbia, and northern Washington.

A lightweight and inexpensive cylindrical-sleeve insect cage is described. The cage was constructed of plastic screening and cotton fabric closed by an open-ended zipper. The cage was successfully used to collect insects from rust cankers on the stems and branches of pine trees.

A list is given of 77 species of arthropods, taken in 1965 from the bracket fungus Fomes fomentarius (L. ex Fr.) Kickx growing on dead birch, in Gatineau Park, Quebec.

The majority of caddisflies selected for discussion in this paper are from Mexico. The Mexican Trichopterous fauna should contain a large number of genera and species, however, relatively few have been recorded, or described from that country. The phylogeny of many nearctic species will be better understood when our knowledge of the Mexican fauna is more complete. With this as the objective, most of the new species selected for description herein will further elucidate our knowledge of the Trichoptera.

One new species of Wormaldia, four new Polycentropus, two new Limnephilus and two new Oecetis have been selected for description. The unknown female of Limnephilus discolor is described. Types are in the senior author's collection unless otherwise indicated.

Two undescribed species of the genus Heptagenia of the maculipennis group are described and illustrated. Heptagenia jewetti n. sp. is known from Oregon, and H. petersi n. sp. from Wyoming and Utah.

Dermanyssus gallinoides is described as a new species of mite. It is parasitic on a sapsucker in British Columbia and has been collected from the nests of a red-shafted flicker and Lewis’ woodpecker in Colorado.

The effects of fluctuating water tables on the survival of the larch sawfly, Pristiphora erichsonii (Hartig) (Hymenoptera: Tenthredinidae), were studied by burying cocoons at different depths in a tamarack bog. Most larvae in cocoons flooded during August or September died before winter. The percentage of overwintering survival of unflooded cocoons remained constant from late fall until development began in the spring. The higher the cocoons were above the maximum water table during August and September, the greater was the percentage of overwintering survival and subsequent adult emergence.

A new subspecies, Helicoverpa pallida nihoaensis, from Nihoa Island, Hawaii, is described. Additional distributional data for Helicoverpa zea (Boddie) in Hawaii are presented, and pupal diapause in a Sudan population of H. armigera (Hbn.) is discussed. The present generic assignment of Heliothis pauliana Viette is questioned, and Chloridea chilensis (Hamp.) is transferred to the genus Schinia.

Eucosma rescissoriana Heinrich is highly destructive to cones and seed of western white pine, Pinus monticola Douglas, and is distributed throughout the geographic range of this host species in northern Idaho. One generation is passed per year with emergence in late May. Egg and larval stages arc generally found in June and July; the pupal stage overwinters. Stand density and elevation were used as variables in ecological studies of population sine. All stages of E. rescissoriana were correlated to phenological data in 1962.

The measurement of insect attraction by the number of specimens collected in a certain time, or by the duration of the attractive effect, does not distinguish between the roles of intrinsic attraction and the attractant concentration. It is shown that the number of D. melanogaster responding to a food odor is proportional to the logarithm of the attractant concentration, in conformity with the Weber–Fechner Law. The implications of this result are discussed.

The immature stages of Epinotia nanana Treitschke are described. Keys are presented for the eggs, larvae, and pupae of the four lepidopterous needle miners known on spruce in Ontario.

Small females of the parasite Nasonia vitripennis (Walk.) parasitized fewer hosts (housefly, Musca domestica L.) than larger ones during their lifetime because they had both a shorter life span and a lower rate of parasitization. The latter resulted primarily from a lower egg maturation rate. As females reared from superparasitized hosts are on the average smaller than those reared from non-superparasitized ones, these effects of parasite size reduce the rate of increase of N. vitripennis at high parasite:host ratios and result in greater stability in the interaction between the two species.

To determine the dispersal of coccinellids in corn fields, two methods were used: sticky traps were placed at different elevations to catch the beetles in flight, and a sucrose solution was sprayed on the upper or lower portions of plants to concentrate beetles.

The results show that the distribution on the plants is closely related to the manner of dispersal of the species, the Hippodamia species fly at a greater height than C. maculata, and H. convergens and H. 13-punctata are, respectively, about 15 and 9 times as mobile as C. maculata. The results generally support the idea that entomophagous coccinellids are more nomadic than their phytophagous relatives.

In August, 1963, silver poplar trees in St. John's West, Newfoundland, were severely attacked by small leaf-rolling caterpillars. Larvae were taken from a poplar tree during mid-August, 1963, and reared in the laboraeory. Moths that emerged were identified as of Anacampsis populella Clerck by Dr. T. N. Freeman, Entomology Research Institute, Canada Department of Agriculture, Ottawa, who also noted (in litt.) that this was apparently tlie first record of the species in Canada. Dr. K. Sattler (in litt.), Munich, Germany, confirmed the identification in 1964. Dr. Kelvin Dorward (in litt.), Chief Staff Officer, Survey and Detection Operations, United States Department of Agriculture, Washington, D.C., stated that the only record of A. populella for North America was for Washington State by Clarke (1942). Clarke stated that E. I. Smith of Entomology and Plant Quarantine, Seattle, Washington, reared moths from larvae collected on a species of Salix, and this appeared to be the first record of the occurrence of this species in North America.

Eretmocerus californicus is a solitary parasite of numerous whitefly species. It is able to develop in all nymphal stages of its host but prefers the second and third. Oviposition and development of the first-instar larva take place under the host, the following two instars develop endoparasitically. Superparasitism is common under artificial conditions, but the supernumeraries are always eliminated during their first or second instar. Adult longevity is highest at 60° and lowest at 100° F. Males are rare and superfluous in Riverside but abundant and essential in Indio. In Riverside, E. californicus is most abundant during the late summer and is almost absent from the field between January and June. In Indio, it is present the year around. Although it attacks the same host instars as Encarsia pergandiella Howard, no hyper- or multiple-parasitism takes place. E. californicus is an important controlling factor on whiteflies in the Coachella and Imperial valleys but not in Riverside and the coastal area.

The median depression on the last abdominal sternite is a useful character for distinguishing, in the field, the male from the female adult of all North American Hylobius species.

Everett and Newsom (1964) used a midline depression or sulcus on the abdominal sternites to separate the sexes of the rice water weevil, Lissorhoptrus oryzophilus (Kushel), and other weevils that are not closely related to species of Hylobius in North America. The male of Hylobius abietis L., a European relative, is distinguished from the female by a saucerlilte depression on the last sternite (Anonymous 1952). Millers et al. (1963) state that the first and second visible abdominal sterna of the male H. rhizophagus Millers are concave, and the fifth has a slight median depression; the female sterna are convex.

The boxelder leaf gall midge is univoltine in Michigan. Adults emerge after the first few warm days in April, and deposit numerous eggs within the folded young leaves of boxelder (Acer negundo L.). Larval eclosion occurs a few days later, and gall development begins shortly after. Head capsule measurements revealed three larval instars. Third-instar larvae drop to the ground near the end of May, work their way into the soil, and construct cocoons. Pupation occurs in late August, and overwintering takes place in the pupal stage. Because oviposition occurs almost always on leaves in a certain stage of development and an estimated 50% of leaves will therefore escape attack, host mortality apparently cannot be caused by this insect.