The larvae of the European pine shoot moth, Rhyacionia buoliana (Schiff.), feed on several species of hard pines, of which the most economically important are red pine, Pinus resinosa Ait., and Scots pine, Pinus sylvestris L. Approximately one hundred million trees of each species mere planted in southern Ontario since 1905, most of them since 1925. Many pure and mixed stands are now infested by R. buoliana which has no apparent preference for either host tree.

Wheats that are resistant to the wheat stem sawfly, Cephus cinctus Nort., differ in degree of resistance and in certain environments lose all or part of their resistance. The survival and behaviour of the larvae in different locations in the stems of various spring wheats have been examined with the object of determining some of the factors involved in resistance and in the variability of resistance. In the previous paper in this series (Holmes and Peterson, 1961) it was shown that resistance to hatching of the egg of the sawfly depended on the stem solidness of its host.

Two principal pests of apple and peach trees in southwestern Ontario are the European red mite, Panonychus ulmi (Koch), and the two-spotted spider mite, Tetranychus telarius (L.). Usually only P. ulmi is present on the trees in large numbers during the spring and early summer, at which time T. telarius lives predominantly on the ground cover. In August, many T. telarius move from the ground cover to the trees, and large numbers of both species may then be present. In mite control investigations in an apple orchard at the Harrow Research Station, T. telarius moved onto the trees, especially in the central plots, regardless of the acaricides previously applied or the numbers of P. ulmi that were or had been present. This phenomenon posed the question of whether the residual effects of acaricides applied to the trees were mainly responsible for the size of P. ulmi populations in the central plots, or whether competition resulting from the ingress of T. telarius was partially responsible.

Incidence of damage to needles of Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, by larvae of gall midges has been noted in British Columbia since 1935. In 1953 severe midge damage to Douglas fir occurred in sections of British Columbia, Washington, Idaho and Montana. Outside of brief and general reference to these gall midges in literature and in unpublished notes, almost nothing was known of their biology, and the species remained undescribed. Relatively little interest has been shown these insects until recent years, when severe infestations in southeastern British Columbia affected the sale of Douglas fir for use as Christmas trees.

Gillette (3) described this species as Chermes similis in 1907. His description was of winged females from galls but he mentioned that wingless females and their egg clusters were also present in some galls, although there was no way to make certain that they were of the same species. The galls were on blue spruce from Colorado, and winged adults from these settled on spruce in cages. Patch (4) reported this species in 1909, on Norway, white, red, and black spruces from Maine. She found that the winged females settled 'on all these spruces but preferred white spruce. Wingless females with egg clusters were present in the galls and she assumed they were Chermes similis Gillette. Annand (1) placed the species in the genus Pineus, along with all species having four abdominal spiracles. He referred to the previous writers, and gave a description of a wingless adult, “probably from a gall”, included with Gillette's type material. He tentatively called this form a fundatrix. He also described a wingless female and a ‘nymph’ which Patch had found associated with galls of P. similis, as Pineus sp.

Severe defoliation of aspen stands by the forest tent caterpillar, Malacosoma disstria Hbn., became apparent in 1948 in three widely separated regions in Ontario, and by 1949 it was clear that another general outbreak of this defoliator had begun. In 1950 the Forest Insect Survey (cf. McGugan, 1958) initiated an intensive program of observation, collecting, and rearing to record the progress of the outbreak and study the parasite complex of the insect. This paper compares the outbreak in the early ‘fifties’ with earlier ones, and attempts to describe the pattern of build-up and decline of forest tent caterpillar populations within extensive forested areas.

The rove beetle, Aleochara bilineata Gyll., is known as a predator and a parasite of the cabbage maggot, Hylemya brassicae (Bouché), in most areas where the latter is an economic pest of cruciferous crops (Wishart, 1957; Wishart et al., 1956, 1957; Hughes, 1959). However, although A. bilineata is an extremely prolific insect (Colhoun, 1953; Wishart et al., 1956), in that the adult beetles destroy root maggot eggs and larvae and the parasite larvae destroy root magpt pupae, little has been reported concerning the economic value of the predator-parasite as a natural control agent. Preliminary studies in Prince Edward Island indicated that the predator destroved large numbers of root maggots but it did not appear to sive economic control (Read, 1960). Details of the biology of this predator have been presented by Colhoun (1953). This is a report of studies conducted to determine the potential value of A. bilineata as a natural control agent, and includes observations on the comparative life histories of host and parasite and notes on predation and parasitism in the greenhouse and on parasitism in the field.

An aerial spray program was conducted by the District of Kitimat, B.C. on August 1, 1960 for the control of the saddle-backed looper, Ectropis crepuscularia Schiff. An oil formulated DDT spray (1/2 pound technical DDT per U.S. gallon), was applied by aircraft at a rate of 1 gallon per acre. The results were inconclusive and raised the questions as to whether the low insect mortality counts were due to inadequate spray coverage or to the relative low susceptibility of the larvae to the DDT formulation. (Silver, 1961).

Alternative chambers are used in laboratory studies of insect behaviour to determine responses to divergent pairs of temperatures, humidities, or light intensities. Theoretically, they provide an efficient means of presenting two different uniform intensities of a physical factor in equal areas that are separated only by a narrow, central boundary zone. In practice. however, only dark-light chambers approach this theoretical ideal. Jn temperature or humidity chambers, the boundary gradient often varies in width and steepness at different points, and the two halves may acquire unpredictably vagrant gradients which change in slope and extent with passing time.

In the Prairie Provinces, newlv harvested grain is seldom infested with stored grain insects and mites when first binned. During the storage period, infestation of grain depends on 1, the proximity and abundance of stored grain pests, 2, the ability of the insects to gain a foothold and cause extensive damage, and 3, the initiai storage condition of the grain. The latter, in turn, is influenced bv temperature, moisture content and the amount of grain dust, chaff and weed seeds present.

The quantities of excreta produced by aphids (Auclair, 1957) and locusts (Dadd, 1960) have been used to estimate the relative consumption of different food materials. Likewise the quantities of food consumed by some other insects have been conveniently estimated by counting fecal pellets (Thorsteinson, 1953; Ito, 1960). Ito (1960) stated without supporting data “there is a highly significant correlation between the amount of mulberry leaves ingested and numbers of feces produced”. Nevertheless there appear to be no published quantitative measurements made on individual insects that show the relationship between the quantities of food consumed and excreta passed. This note gives the relationship between the quantities of dry matter (D. M.) consumed and excreted for three larval instars of the pale western cutworm, Agrotis orthogonia Morr., fed two varieties of etiolated wheat sprouts, Thatcher (Triticum aestivum L. emend Thell.) and Golden Ball (T. durum Desf.). In addition the relationship between D. M. consumed and numbers of fecal pellets produced or D. M. excreted by fifth-instar larvae were determined for two diets that differed considerably in nutritional value.

The genus Psithyrus Lepeletier is closely related to the genus Bombus Latreille. A large number of similar and dissimilar characters of these genera have been enumerated (Richards, 1927), but the major modification of Psithyrus to an obligate, parasitic mode of life has been the loss of the pollen-collecting apparatus and the lack of a worker caste. However, Psithyrus still visits flowers for nectar, and the general morphology of the “tongue” has not been modified as has the pollen-collecting apparatus. Detailed measurements on the labium of Psithyrus have not been reported previously. This paper gives data on 10 species. The information adds to basic knowledge on Psithyrus, and may be of value in relation to the question of the monophyletic or polyphyletic derivation of species of Psithyrus. Also, as with Bombus, considerable variation exists in the sizes of the parasitic bees, which is associated with the nutrition of the larvae. The measurements of the radial cell of the forewing show size relations within a species. The length of the radial cell (Fig. 1) has been selected as the most convenient method, although the size of an individual can be expressed also by the measurement of either its wing length or weight.