Male.—Length 10 mm.; antenna 8 mm.

Head shining; vertex feebly convex ; front with sparse weak punctures Malar space scarcely one-fourth as long as basal width of mandible. Thorax shining; sparse weak punctures on dorsal third of pronotum, meso-scutum, scutellum, anterior half of mesopleura, mesosternum and metapleura; propodeum with distinct rather dense punctures except for polished mid-dorsal area where punctures are obsolete.

The oviposition behavior of the pteromalid parasitoid Nasonia vitripennis (Walker) was investigated in an attempt to explain the difference in population density maintained on two species of host, the housefly, Musca domestica L., and the blowfly, Phaenicia sericata (Meigen). The behavior of a female wasp was significantly affected by the species of host to which she was exposed. When presented with 10 pupae for 24 hours she averaged 14.2 eggs on 3.0 housefly hosts and 8.3 eggs on 7.2 blowfly hosts of the same size.The importance of the alteration in behavior to the population density of Nasonia became apparent when the suitability of the two host species was examined. At all densities of eggs more wasps matured on blowfly pupae than on housefly pupae of the same size. Survival on both hosts decreased as the density of Nasonia eggs increased. The difference in egg distribution, coupled with lower survival on housefly pupae and at increased density suggests a considerably lower production by this parasitoid on housefly hosts, compared with that on blowfly pupae.

A study of the caddis flies of Waskesiu Lake was carried out during the summer of 1940 as part of the general program of limnological investigations which have been conducted in Prince Albert National Park, Saskatchewan, since 1928. The importance of caddis flies in the ecology of the lake had been recognized since they provide much food for fish in the near shore reginn.

Male moths of Euxoa pleuritica (Grote) were strongly attracted to mixtures of Z7-dodecenyl acetate, Z7-dodecenyl alcohol, and Z5-dodecenyl acetate, the optimum ratios being in the range 5:1:1–5:5:1. The attractant worked best at very low dose levels and was entirely species-specific.

The potential usefulness of Nosema locustae Canning as a microbial agent for grasshopper control was first demonstrated by Henry (1971) and Henry et al. (1973). These authors found that a 50–60% reduction in grasshopper density (as compared with untreated populations) could be achieved, and they speculated that 35–50% of the survivors would be sufficiently infected so that their fecundity would be reduced. The value of incorporating such an agent into a grasshopper pest-management system is obvious: By suppressing high insect densities to manageable levels, the need for conventional chemical insecticides could be reduced and perhaps even restricted only to “hot spot” areas. The objectives of the study we report here were to: (1) Determine if N. locustae was infective to the predominant species of grasshoppers in Saskatchewan; (2) if so, monitor the development of the disease within the populations; and (3) determine if the pathogen could survive over the winter and infect next year's populations. Because this was a preliminary experiment, we did not attempt to determine any effect the pathogen might have on population reduction.

Calling by newly emerged female Lambdina fiscellaria lugubrosa (Hulst) began the first evening and commenced 15 h after the onset of light in nature and in a 14L:10D photoperiod regime in the laboratory. Copulation began 0.5 to 1.5 h later, and moths remained in copulation an average of 3.45 h. The internal reproductive system is typical of ditrysian-type Lepidoptera. Mating usually resulted in the transfer of a single, spheroid spermatophore with a long collum. The spermatophore was placed in the bursa copulatrix in such a position that spermatozoa could leave through the aperture into the ductus seminalis. The greatest mating success occurred between 2- to 4-day-old males and females up to 4 days old. Maximum oviposition occurred on the day after mating. Numbers of eggs maturing and being laid were increased after mating. Mean longevity of mated and unmated females in the laboratory was 18.1 and 20.8 days, respectively. Mating success was greatest at a 6:1 male to female sex ratio, and progressively less at a 1:1 and 1:6 sex ratio. Males mated only once in a 24-h period, but were capable of multiple mating. Females usually accepted one spermatophore but occasionally up to three were found.

Efficient sampling procedures for estimating densities of eggs of Douglas-fir cone gall midge (DFCGM), Contarinia oregonensis Foote, on individual trees as well as for orchards were developed from data collected in Douglas-fir seed orchards in 1978–1981. Egg distribution was contagious and generally fitted the negative binomial distribution on individual trees, but a common k could not be estimated. Tree and crown level affected density of midge eggs within orchards. Average density at the midpoint of the cone-bearing portion of the crown was not significantly different from the tree average. The optimum sampling pattern in an orchard, i.e. one conelet from the midpoint of the cone-bearing portion of each of 120 trees, would require 120 person-hours to process the samples when DFCGM egg densities are high (worst-case situation).

A small colony of the striped flea beetle, Phyllotreta striolala (F.), has been maintained in a cage in the greenhouse for more than 21/2 years. Horseradish [Armoracia rusticana (Lam) Gaertn., Mey. & Scherb.] was found to be a suitable host plant, and the caged beetle colony has followed a similar life cycle to natural populations in the field.

Adult and nymphal populations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), on “Contender” green beans, Phaseolus vulgaris L., were sampled during the summers of 1971–1972. Sweep net and D-Vac® suction apparatus samples were taken concurrently, and both estimates were compared by regression analysis.

The tarnished plant bug reached levels above the economic injury levels for both early and late crops in 1971–1972. The economic threshold was determined as 0.5 insect/10 plants below the economic injury level.

Distributional and anatomical characteristics of the species of the western North American genus Cordylospasta are analyzed. The current concept of this genus is a considerable modification from that of earlier classifications.

Of the two species belonging to Cordylospasta, C. fulleri Horn is unique among North American blister beetles in having antennae with 8 to 10 antennal segments. This species is strictly allopatric to the second species, C. opaca (Horn), in which the antennae are 11-segmented.

Step-clinal geographic variation in seven anatomical characters is recorded for C. opaca. On this basis six biological races are recognized as occurring in central and southern California. These are considered the equivalent of subspecies. An informal approach to the recognition of these infraspecific taxa is followed since, due to limited material, interracial reproductive relationships cannot be inferred confidently at the present time.

The pine engraver, Ips pini Say, and Pityogenes knechteli Swaine often co-exist in lodgepole pine, Pinus contoita var. latifolia Engelmann. We tested the hypotheses that P. knechteli produces an attractive pheromone and that the attraction of P. knechteli and I. pint to conspecifics is inhibited by the presence of the other species. Pityogenes knechteli males and females were attracted to bolts infested with conspecific males and to bolts infested with I. pini males; however, there was no significant cross-attraction of I. pini males or females to bolts infested with P. knechteli males. Attraction of P. knechteli and I. pint males and females to bolts infested with conspecific males was not inhibited in the presence of bolts infested with males of the other bark beetle species. Pityogenes knechteli has no potential for competitive displacement of I. pini but may enhance the adverse effect of I. pini on the mountain pine beetle, Dendroctonus ponderosae Hopkins.

Aggregation sites for male Cuterebra grisea Coquillett were found near areas where deermice were infested by botfly larvae. At these sites which were near streams or roadsides, male C. grisea flew over heat-reflecting surfaces which often contained objects taller than their surroundings. Each male chased intruders, including other males, from a territory over which it flew at regular intervals in an oval or figure-of-eight pattern. They flew in mornings during July and August provided the shade temperature was above 19.5°–20 °C and the sun was shining or had been shining. On very warm mornings when 20 °C was reached early in the morning, males did not fly until about 33/4–4 hours after sunrise. Flight almost always ended by midday. Female flies were rarely seen because they appeared only long enough to be mated. The data on C. grisea led to the discovery of similar male aggregation behavior of the pack rat botfly, C. tenebrosa Coquillett.

The larva of Nomophila noctuella D. & S. is described and illustrated. Five specimens from Germany compared with those from Ottawa, Canada, showed no specific differences.

The Phoridae chapter in the "Manual of Nearctic Diptera, Volume 2" is updated to include newly collected material. Genera new to North America are as follows: Dacnophora Borgmeier, represented by D. pectinatus nov. sp. from Arizona; Ecitoptera Borgmeier and Schmitz, represented by a single badly damaged, undescribed, female specimen from Arizona; Kerophara gen. nov., represented by the type species K. ferruginea sp. nov. from Alberta, K. brunnea sp. nov. from Alberta, and K. sicula sp. nov. from Virginia; Mennoziola Schmitz, represented by a single, undescribed female specimen from Florida; and Styletta Borgmeier, represented by the widespread species S. camponoti sp. nov. The monobasic Borgmeieria Prado is shown to be congeneric with Neodohrniphora Borgmeier (syn. nov.) based on examination of the previously unknown female, and the names are synonymized. Also, the undescribed female of Abaristophora Schmitz is briefly diagnosed; species of the genus Bactropalpus Borgmeier are known to be the males of Trophodeinus Borgmeier; the genus Gymnophora Macquart has recently been revised; Lecanocerus Borgmeier probably does not belong to the Beckerinini; and Microselia Schmitz and Rhyncophoromyia Malloch are included in the Manual key. Corrections, additional couplets, and illustrations for the Manual key reflect this new knowledge.

Hymenochara, a new genus of Alleculidae, is described based on Mycetochara rufipes (J. E. LeConte) from eastern North America and Hymenochara arizonensis new species, from Arizona.

During current studies of Cerambycidae at Laniel, Quebec, new information on the immature forms and biology of the common woodborer, Xylotrechus colonus (Fab.) was obtained. This species belongs to the tribe Clytini of the subfamily Cerambycinae, and was first described by Fabricius in 1775 as Callidium colonus. Packard (1890) described and figured the larva, pupa, and adult in a general way; the mature larva was described in detail by Craighead (1923). Synonomy and adult description were given by Hopping (1932).

Three new species of fossil Tipulidae are described. Pseudolimnophila speirsae n. sp. and Limnophila marklae n. sp. (subfamily Limoniinae, tribe Hexatomini) are represented by adults; Tipula tubifera n. sp. (subfamily Tipulinae, tribe Tipulini) is represented by a pupa. Six other pupae belong to the subfamily Tipulinae.

With the increased availability of radioisotopes and their application to the study of insect behaviour and dispersal, the possibility of using a radio-active tag on grasshoppers was investigated. Preliminary studies on the distribution of radio-active phosphorus (P32) in Melanoplus mexicanus mexicanus (Sauss.) and Camnula pellucida (Scudd.) were carried out by Murray (1949) and Fuller (1950). The P32, in the form of phosphate ion, was placed on food plants in drop form, or the leaves were dipped in an aqueous solution containing the phosphate ion. When this was fed to the grasshoppers over 50 per cent of the activity was excreted, but the amount retained was distributed throughout the body. The highest activities were recorded for the thorax and the metathoracic legs. The radio-activity apparently had no ill effects on the grasshoppers. However, more specific data were required to determine how well the applied activity is taken up and how long it is retained.

In the Canadian Rocky Mountain National Parks, the lodgepole needle miner has a two-year life cycle, so that larvae of each generation are exposed to two successive winters. Although there is no doubt that mortality of these over-wintering larvae is directly attributable to a period of low temperature, there has been some doubt as to whether the bulk of the mortality occurs during the coldest part of the winter, or whether it occurs during periods of low temperature during the late autumn or early spring. Although spring and autumn mortality undoubtedly take place, estimation of the relative importance of mortality during the various seasons must await successive sampling throughout the three seasons. Nevertheless, in the absence of such data, we wish to present evidence that points to the major importance of the weather of the coldest month of the winter to not only the amount but also the vertical distribution of larval mortality.