Macrosiphum parvifolii is described from British Columbia. It is a heavily pulverulent, almost flocculose species that is known only from red huckleberry, Vaccinium parvifolium Sm.

Data are given on the biology of several species of Trichoptera in the Metolius River, Oregon, based on drift and benthos samples. Twenty-seven species were collected. Species of Limnephilidae, Brachycentridae, Hydroptilidae, and Lepidostomatidae were important drift components. The Metolius River is extremely productive, with a mean density of larval Trichoptera of 7400 per square meter in benthos samples and a maximum of 5000 per 24 hours in drift-trap samples. Different species varied in their tendency to drift, in the age class distribution in the drift, and in diel periodicity. Drift-trap collecting is shown to be a useful method of studying aspects of behavior such as the dispersal of larvae and the emergence of pupae.

The San José scale, Aspidiotus perniciosus Comstock, died within 8 to 22 weeks on McIntosh, Red Delicious, Common Delicious, Winesap, Rome Beauty, and Newtown apples harvested on commercial picking dates and placed in standard cold storage. The scale died in much shorter periods on early maturing varieties than on late maturing varieties.

The later a variety was harvested the longer the fruit had to be stored to kill the scale. The maximum storage period was 32 weeks for Winesaps and Newtowns harvested in early November, approximately 1 month after the commercial picking date.

The storage period required to kill the San José scale on Winesap apples varied from year to year, cool weather in early autumn apparently increasing the storage period.

The effects from treating populations of predacious mites with a number of spray chemicals are tabulated. The species include Phytoseiidae: Typhlodromus pyri Scheuten, T. rhenanus (Oudms.), Amblyseius fallacis (Garman), Phytoseiulus macropilis (Banks), Amblyseius finlandicus (Oudms.); and Raphignathidae: Mediolatta novae-scotiae Nes. The chemicals include fungicides, acaricides and insecticides.

The escutcheon or badge of the Lyman Entomological Museum (see Can. Ent. 96(12) cover and page 1485) bears a likeness of Haploa confusa (Lyman 1887), which was originally described in the genus Callimorpha. The species was described from four syntypic specimens in Lyman's collection, all from Montreal. Four additional specimens in “the Cambridge Museum” (Museum of Comparative Zoology, Harvard University, Cambridge, Mass., U.S.A.) are also syntypes as they were mentioned by Lyman following the original description. To date, no lecrotype has been selected for this species.

The pre-storage treatment of fruit with either an antiscald inhibitor or an alcohol solution for segregating water core apples, increased the rate of mortality of the San José scale, Aspidiotus perniciosus Comstock, on Winesap apples held in storage.

The dewaxing and waxing process had little effect on the mortality of the San José scale. The process mechanically removed the scale from the cheeks and shoulders of stored apples but not from the calyx and stem ends.

The Engelmann spruce weevil, Pissodes engelmanni Hopkins, is an indigenous pest of spruce regeneration in western Canada and the adjacent United States. It is univoltine, overwintering as an adult in the duff beneath the host trees. Eggs are deposited in feeding punctures in the terminal leader. Larvae feed downward in the phloem causing two or more years loss of height growth. Deformities incurred by three or more consecutive years of weevil attacks produce a tree of no commercial value. The incidence of weevilling is most numerous in open grown, even-aged, young stands. Of 14 insect parasites and one predator, Dolichomitus terebrans nubilipennis (Viereck), Eurytoma pissodis Girault and Lonchaea corticis Taylor are considered principal natural control agents.

The mycetangia of Corthylus columbianus Hopkins are described. These structures lay immediately below the integument of the pronotum, one in each ventrolateral region. Each mycetangium is a coiled tube 4.69 ± 0.35 mm. in length, cream colored, opening into the anterior coxal cavity. Mycetangia occur only in the male beetle and provide the overwintering storage site and transmission mechanism for associated microorganisms. Smears and cultures of the mycetangia were positive for ascospores and vegetative cells of a yeast, Pichia sp., which coincides with the microsymbiote dominant in developmental chambers of the larvae.

Irradiation of specific regions of 5- to 20-h-old housefly pupae with X-rays shows that exposure of anterior seven segments alone to 1200 r prevents adult emergence, whereas irradiation of posterior region with doses up to 10,000 r has no effect on this phenomenon. It is evident that the target organ, damage to which results in the failure of adult emergence, lies in the anterior seven segments. It is suggested that failure to emerge is due to a direct effect of radiation on the differentiating myoblasts leading to dystrophy of the muscles.

The two-spotted spider mite, Tetranychus urticae Koch, showed a pronounced two-peak diel periodicity of susceptibility to dicofol, in a natural regimen of light: dark. The first occurred between 0200 and 0500 hours and the second between 1300 and 1800 hours. Mortality dropped sharply after sunrise (0441 hours) and again an hour before sunset (2002 hours). Lowest mortality occurred near midday. Egg-laying was inversely related to mortality over the 24-hour period.

An assay procedure for estimating the dosage–response relationship of early instar larvae of the onion maggot, Hylemya antiqua (Meigen), to insecticides is reported. The method gave reproducible results for diazinon on several test dates. The assay showed that maggots from strains collected at East St. Paul and Portage La Prairie, Man., tolerated 50 to 108 times as much heptachlor as a susceptible strain from Chatham, Ont. Previously, adults from the Manitoba strains had been shown to be highly tolerant to heptachlor. The potencies of Bayer 37289 and Bayer 25141 relative to diazinon were 0.5 and 0.1, respectively, for a heptachlor-tolerant strain. For NIA 10242 and Nemacide, equivalent values were 0.9 and 0.2 for this strain and 1.0 and 0.2 for the susceptible Chatham strain. The slight differences in the tolerance to these insecticides, shown for the two strains of larvae, were not associated with their tolerance to heptachlor.

Drifting of honey-bees in a bee flight and rearing room quickly results in imbalances in hive populations. Orientation cues (coloured walls, coloured boards over the hive entrances, symbols on the walls, and objects located in the room) do not reduce drifting. Hive position in the room affects the direction of drifting, with one colony gathering-in a high proportion of the drifting bees.

Diapause induction in Hyphantria cunea is under the joint control of photo-period, temperature, humidity, food quality, and possibly other variables, but insufficient data are available to permit a precise evaluation of their actions and interactions. Short daylength and low temperature induce diapause and the critical thresholds for New Brunswick – Nova Scotia populations are in the vicinity of 14.3 hours and 72°F, respectively. Low humidity increases the incidence of diapause, as does also the change in the nutritional quality of foliage late in the season. Both field data and the extrapolation of laboratory data to field conditions indicate that the occurrence of a partial second generation is unlikely in this area, even in warm seasons.

Barylypa irona, a new species of ichneumon fly from Michigan, is described.

Various aspects of the behavior of I. confusus (LeConte) relating to the production of and response to male attractant were studied. Storage at 8.0 °C and 100% R.H. had no adverse effect on survival, response to male attractant, or predisposition to fly. Low humidity and high temperatures (21 °C) adversely affected behavior and survival. Beetles conditioned either in natural or constant environments responded at high levels throughout a 24-hour period. Female response to male frass reached a low of 24.2% in January and February and rose to a peak of 76.6% in May and June. Response to benzene extract of male frass fell moderately during autumn and winter, indicating a lowered response ability for overwintering populations. Male response was lower and more erratic but followed the same seasonal trends.

After brief exposure periods, even previous nonresponders oriented to male attractant at significantly higher levels than the total original population. Long-term confinement in an atmosphere containing male frass odor caused a reduction in response of both sexes to male frass extract, presumably because of adaptation of olfactory receptors.

Flight attempts by both sexes occurred between 25° and 40 °C but were severely inhibited at these extremes. Light intensities below 431 luxes suppressed flight. Optimal take-off temperatures were 30 °C for males and 32.5 °C for females. Both contact with male frass and with attractive air reduced the take-off attempts of both sexes to near zero. Attractive odor in the air still suppressed flight significantly after beetles had been conditioned up to 4 hours in contact with male frass.

Teneral males produced attractant after a long maturation period. Single, mature males produced attractant up to 18 days, but after mating, productivity declined in direct correlation with the number of females per male. Single males produced frass throughout the day but maximum production was coincident with peak female emergence and flight. Male frass was significantly less attractive 15 minutes after exposure to open air and after 1 hour, very little attraction remained.

No trends in the ability of newly emerged adults to respond to male attractant were noted over a 30-day period. Emerging brood and re-emerging parent adults are responsive to flight stimuli, but darkened callows and parent adults removed from galleries could not be induced to fly. Reproducing females show a greatly reduced response to male attractant.

Male Grapholitha molesta (Busck) treated with 40 krad of gamma radiation in the late pupal stage reduced egg-hatch by 93.6%, and in the young adult stage by 96.4%, in eggs from untreated virgin females with which they were mated; in addition, hatched larvae failed to complete development. Induced sterility was consistently greater in treated adults as compared with treated pupae. Females in the late pupal stage were sterilized with about 10 krad.

Male longevity decreased in proportion to the radiation dosage above 30 krad when caged at a ratio of 3 ♂: 1 ♀. Longevity of untreated males decreased in proportion to the number of females available for mating.

Radiation levels of 30 krad or more decreased male mating, especially when applied to the pupal stage, in inverse proportion to dosage, as detected by caging males with three times as many females.

The number of matings per untreated male increased with the number of females available up to an average of 3.8 while the number of matings per female averaged approximately 1.6 with from one to three males per female.

The distribution of Douglas-fir tussock moth (Hemerocampa pseudotsugata McD.) egg-masses on white fir (Abies concolor (Gord. and Glend.) Lindl.) was studied in three areas of northern California. In each area 100 trees between 4.5 and 8.4 in. in diameter were stratified into five defoliation classes and four crown classes, giving a total of 20 classes per study area with five trees per class. Trees were divided into four crown levels and samples were taken at each of the cardinal directions at each level. Two branches comprised n sample unit in the top half of the tree (eight branches per level) and one branch the sample unit in the bottom half of the tree (four branches per level). Egg masses were recorded per 10 sq. ft of foliage or branch area. Eighty per cent or more of the egg masses were found in the bottom half of the crown. This percentage in the bottom half of the crown increased on trees with heavy defoliation or with increased exposure of the crown. Of the four possible sources of variation considered in this study, crown level, defoliation class, and crown class were significant while cardinal direction was not. A sampling method is proposed on the basis of the information gathered in this investigation.

Head capsule measurements of the ambrosia beetle Xyloterinus politus (Say) revealed three larval instars. The xylomycetophagous larvae lengthened their cradles and a positive correlation existed between head width and cradle length. A sex factor of 0.84 was in favor of the female adults. Dissection of active galleries revealed only a single female per gallery. Males were never seen to initiate or excavate a gallery and were forced from the entrance hole by the female when placed in an active attack. The gallery system studied was simple, the entrance hole penetrated into the sapwood for a variable distance before it branched into secondary tunnels at right angles to the main gallery.

Eggs were laid singly in cup-shaped cradles excavated by the female. The cradle openings were plugged with frass throughout the duration of the immature stages. Callow adults emerged from the cradles by forcing the frass plug covering the entrance, and re-entered, their position reversed to feed upon the ambrosial fungus growing on the cradle walk X. politus overwintered as an adult in the old cradles and galleries. Larvae of Ipideurytoma sp. (Hymenoptera: Eurytomidae), probably a larval parasite of X. politus, were found in cradles.

A model is presented which describes the effect of sterile male release on a wild population. This model is not subject to restrictions, such as equal competitiveness between normal and sterile males and sperm nor to insect species whose females mate only once. The model is an approximation as it assumes constancy in several dynamic population variables. However, it has application in determining the approximate effects of sterile male release and in decisions on the number of sterile males required for release programs. It also has uses in ecological research.

An additional record of the tunnelling habit of Ips plastographus (Leconte) is reported and illustrated and the function of the habit is discussed.