Host selection by the hickory timber beetle, Xyleborus celsus (Coleoptera: Scolytidae), was studied using axe-girdled, herbicide-treated, and healthy black hickories, Carya texana (Buckley), 10–25 cm D.B.H. Many more beetles were caught on sticky traps placed on treated trees than on sticky trees placed on untreated trees. Traps on treated trees 17 cm D.B.H. or larger caught more beetles than traps on trees 10–15 cm D.B.H. The interval between treatment and initial beetle attack varied with season. Beetles were not attracted to window flight traps baited with 118 ml of 95% ethanol.

Nine sampling units for estimating southern pine beetle population within a tree are compared according to unit size, strata size, and number and type of sampling allocation. As a measure of performance of different sampling schemes or different unit sizes the ratio of the variances of the estimate is used, i.e. relative efficiency.

Relative efficiency decreases as unit size increases, where equal surface area is sampled. Unequal stratification, which allocates smaller area to the upper and lower strata, results in higher relative efficiencies than equal stratification. Thus, unequal stratification is recommended. Samples should be allocated to these strata according to the optimal sampling ratios.

Tarsonemus waitei Banks, 1912, T. setifer Ewing, 1939, and T. pauperoseatus Suski, 1967, are shown to be conspecific (new synonymy). Tarsonemus bakeri Ewing, 1939, thought to be conspecific with T. setifer for the last 25 years, is shown to be specifically distinct. Both sexes of these species are redescribed and reillustrated, and character state variability expressed within populations of T. waitei is discussed. The waitei species group, previously called the pauperoseatus group, is redescribed for these and other species. A provisional key to the known member species of this group is given. This group is judged to be insufficiently distinct from some of the other species of Tarsonemus to warrant recognition as a subgenus.

A new trapping technique which selectively captures Culex sp. mosquitoes during oviposition is described. A comparison of this trap to CDC and CO2 traps is presented and the advantages of the oviposition trap for viral monitoring discussed.

Due to concern over an outbreak of bluetongue disease in cattle near Osoyoos, B.C., a survey of Culicoides spp. was made and the seasonal and immediate geographical distribution of the known large-mammal biting species studied. Species found included C. cockerelli (Coquillett),C. crepuscularis Malloch, C. near haematopotus, C. jamesi Fox, C. montanus Wirth and Blanton, C. obsoletus (Meigen), C. occidentalis Wirth and Jones, C. palmerae James, C. piliferus group, C. travisi group, C. variipennis (Coquillett), C. yukonensis Hoffman, and Leptoconops kerteszi Keiffer. The active period for adults of C. occidentalis, a proved vector of bluetongue disease, is from mid-April through early October. Breeding sites of this species were common from 275 to 600 m above sea level throughout the area of bluetongue disease incidence. Breeding sites extended up to 1350 m and adults were trapped at 1820 m. A large number of adult C. occidentalis and other Culicoides spp. were collected for isolation of bluetongue virus. No virus was recovered. This was possibly due to large-scale testing of susceptible domestic animals for bluetongue virus antigens and removal of those giving positive reactions prior to collection of the insects tested.

Three new species, two in the genus Amblyseius Berlese and one in the genus Typhlodromus Scheuten, collected in Canada are described. Three additional Amblyseius species and one Typhlodromus species are recorded for the first time in Canada. The previously unknown males of 9 species are described. These new records bring the total numbers of species in the genera Amblyseius and Typhlodromus in Canada to 53 and 22 respectively.

The banded woollybear, Pyrrharctia (Isia) isabella (J. E. Smith,) was reared under laboratory conditions from egg to adult. Individually reared larvae were fed one of six artificial diets and fresh plantain at 26 °C, light/dark (h) 15/9. The times of moulting, larval and pupal weights, and adult characteristics (fertility, sex) were recorded.

Larvae were easily reared on bean, wheat germ, casein – wheat germ and fresh plantain, while casein, alfalfa, and plantain diets proved unsatisfactory. Rearing procedure and developmental characteristics are discussed.

Dendroctonus terebrans (Olivier) adults may be accurately sexed by means of the seventh abdominal tergite. Stridulation sound and stridulation movement are useful especially in field observations but not completely accurate because some male beetles do not stridulate and some females do.

Laboratory rearing is accomplished by the introduction of parent beetles to fresh pine bolts. Development takes ca. 78 days at 23 °C ± 2 °C or ca. 1302 degree days of effective temperature.

The development of Ceuthorrhynchidius horridus (Panzer) was observed on five diets consisting of less than 15% dry weight of host-plant material. Adult yields per inoculated larvae were low (less than 1%), although yields from uncontaminated last instars reached as high as 16.6%. Comparisons of diet versus plant-reared weevils showed that (1) larval weight gain at 28 days was significantly greater for plant-reared larvae, (2) plant-reared adults were significantly larger than diet-grown weevils, but there was no difference in fertility, and (3) egg size, viability, and first instar head capsule widths were not significantly different for progeny from diet and plant-reared weevils.

Because laboratory and field cage experiments had shown that partially sterile (25 krad dose) male codling moths were sexually more competitive than sterile (40 krad) ones, a study was made in a British Columbia orchard in 1970 to determine whether release of 25 krad moths of mixed sexes would suppress this pest more effectively than release of 40 krad moths. Approximately 75,000 moths/ha were released from 24 April to 25 September for each dose level. In the 25 krad moth release plot, the percentage of apple fruits damaged by this pest at harvest was reduced from 0.21 in 1969 to 0.08 in 1970, whereas in the 40 krad plot damage was reduced from 0.04 in 1969 to 0.02 in 1970.

Release of 25 krad moths was also compared with insecticide sprays for codling moth suppression in two small areas at Cawston and Olalla, B.C. At Cawston, the percentage of apples damaged at harvest was reduced from 1.0 in 1969, after three sprays of phosalone, to 0.1 in 1970 after release of irradiated insects. In contrast, per cent damage in a nearby apple orchard, sprayed twice with azinphos-methyl in 1969 and 1970, increased from 2.0 in 1969 to 8.1 in 1970. At Olalla, per cent damage was about the same (0.5) in 1969, after three phosalone sprays, as in 1970 (0.6) after release of irradiated insects. In a neighboring apple orchard, sprayed twice with phosalone in 1969 and 1970, per cent damage was about the same (1.0–1.2) each year.

Adult emergence of Simulium verecundum S. and J. and S. decorum Walk. was reduced 58–94% by exposure of late instar larvae to 0.1 ppm Altosid or Altosid SR-10 for 1 h. Pupae were not affected by the presence of 0.1 ppm Altosid SR-10 in the rearing water. Adult emergence of S. verecundum was reduced 95% when mixed larval instars were reared in the presence of 0.001 ppm Dimilin. Last instar larvae died as a result of abnormal metamorphosis. Black fly mortality was 86–100% with 1-h exposures to 0 1–0.2 ppm Dimilin, and 100% with a 15-min exposure to 1 ppm at 22 ± 2 °C, lower temperatures giving similar results.

Release of Altosid over a 48-h period from formulated blocks gave a concentration of 0.002–0.006 ppm in a small stream. Emergence of adults was completely suppressed for 23 days 18 m downstream and 17 days 43 m downstream. Applications of 1 ppm Dimilin for 15 min to two streams resulted in the gradual elimination of black fly larvae from artificial substrates, a high reduction in adult emergence, and the formation of abnormal larvae following the tests. The maximum concentration of Dimilin detected in the water was 0.31 ppm during application; however, submerged vegetation residues as high as 18.9 ppm were found 1 h following the second application, decreasing to less than 0.05 ppm 14 days later.

Arthrolytus (Anadolytus) oezbeki n. subgen., n, sp. is described from Western North America. Some biological aspects of the species are discussed.

Parasitoid-host records were gathered during a study of the arthropod fauna of alfalfa Medicago sativa L., at Ithaca, N.Y., during 1966-71, Dates and number of rearings are given for 46 parasitic taxa. Nine new parasitoid-host relationships are reported.