Nosema acridophagus Henry was shown to be more virulent than N. cuneatum Henry to 3rd-instar nymphs of Melanoplus sanguinipes (Fab.) following peroral inoculation with 1.0 × 106, 105, 104, or 103 spores/individual. The lethal time was dose dependent and significantly shorter and the lethal dose (LD50) was significantly lower in grasshoppers inoculated with N. acridophagus than for those inoculated with N. cuneatum. Grasshoppers inoculated with N. acridophagus died earlier and a smaller proportion survived to the adult stage compared with those inoculated with N. cuneatum. Nosema acridophagus was more infectious at the lower doses than was N. cuneatum; however, N. cuneatum reached an intensity of infection in host tissues which was 2–10 times higher. Both microsporidians appeared to have similar pathogenicity for both individually and group-reared M. sanguinipes.

Three hundred and forty-one primary types of Braconidae housed in the Canadian National Collection were examined and listed. These were contributed by the following authors: Fischer (68), Mason (61), Loan (48), van Achterberg (32), Muesebeck (22), Bhat and Gupta (20), McComb (18), Walley (18), Wharton (15), Viereck (7), Martin (6), Saffer (6), Loan and New (5), Provancher (3), Bhat (2), Loan and Wylie (2), Gupta and Bhat (1), Loan, Klein, and Coppel (1), Mackauer (1), Matthews (1), Richardson (1), Sharkey (1), Shenefelt (1), and Walley and MacKay (1).

Douglas-fir cones were collected from 17 seed orchards in California, Oregon, and Washington in the fall of 1983. Cones were completely dissected and seed losses ascribed to the Douglas-fir cone gall midge (Contarinia oregonensis (Foote)), the Douglas-fir seed chalcid (Megastigmus spermotrophus (Wachtl)), the Douglas-fir cone moth (Barbara colfaxiana (Kearfott)), and the fir coneworm (Dioryctria abietivorella (Groté)). There appear to be great differences between orchards, but overall C. oregonensis and M. spermotrophus collectively destroyed approximately 70% of the filled seed. Physiographic province significantly (P<0.05) explained variation in damage by all insect species between seed orchards. In general, damage by all species increased from northern provinces to southern mountainous provinces. Damage by C. oregonensis and B. colfaxiana appeared to be related to land use or management factors, as well.

During 2 field seasons, Coccinellidae (primarily Coccinella transversoguttata richardsoni, Coleomegilla maculata, Hippodamia convergens, H. tridecimpunctata, and H. glacialis) were the most abundant predators on potato hybrids (Solanum tuberosum × S. berthaultii, F3) with various densities of glandular pubescence. Highly pubescent clones had the highest percentage of predator eggs, while clones with the lowest trichome densities had the highest percentages of immature and adult predators. By comparison, high numbers of aphid parasitoid mummies (primarily Aphidius and Praon spp.) occurred on clones with moderate to high densities of glandular pubescence. During both years, predators and parasitoids were most abundant in late July and August.

The life cycle, feeding behavior, and feeding damage of the spruce budmoth, Zeiraphera canadensis, were studied in northern New Brunswick. Larval emergence, which began in late May, was usually completed within 10 days. First-instar larvae did not feed on the previous year's foliage and took less than 30 min to settle inside a growing shoot, from which they exited only at the end of larval development. Larvae then dropped to the ground and remained as prepupae for approximately 6 days. Mating could be observed the first night following adult emergence. The majority of the mated females contained only 1 spermatophore (92%); others had 2 (7%) or 3 (1%). Although 95% of the egg clusters had 7 eggs or less, 5% had up to 19 eggs. Eggs required embryonic development before successful diapause could be initiated. The importance of these observations in the development of management strategies for this pest is discussed.

Banchus flavescens Cresson is the most abundant hymenopterous parasitoid of the bertha armyworm, Mamestra configurata Walker, in western Canada. The females attack 1st, 2nd, and 3rd instars of the host. The speed of parasitoid development is adjusted so that the 2nd instar is completed when the host finishes feeding. Banchus flavescens has an obligate diapause and overwinters as a prepupa within a cocoon in the soil. Notes on life history and descriptions of the egg and 5 larval instars of B. flavescens are given.

The effects of Panonychus ulmi (Koch) density on several yield components of Red Delicious apples in a Nova Scotia orchard were examined from 1967 to 1970. The same 96 trees were sampled in each of the 4 years, and from a peripheral sampling zone within each tree the number of dormant and blossom clusters and the eventual number of apples produced was determined. The other yield components — bloom, set, and crop — were computed from these counts. Applications of ryania, carbaryl, and animert on 6 June 1967 followed by supplementary applications of animert on 7 July (carbaryl plots) and 1 August (ryania plots) were used to induce varying densities of P. ulmi. Mites were sampled twice weekly from June to August and fortnightly in September. Chemical treatments in 1967 had significant effects on mite-days/leaf in each year from 1967 to 1970. Cumulative mite-days/leaf had a significant negative influence on the number of harvested apples/sampling zone in 1967 and 1969, the years of higher apple production and higher mean bloom, but not in 1968 and 1970. Mites in 1969 also had a significant negative effect on return bloom in 1970. These findings agree with other studies that suggest an interaction between fruit load and yield losses induced by mites.

The species of plant on which larvae of Mamestra configurata (Wlk.) fed had significant effects on the rate of larval development, larval and pupal survival, pupal weight, the percentage of females that mated, and the number of fertile eggs/mated female. Among the four plant species tested, using living plants, the canola cultivars (Brassica napus cv. Regent and B. campestris cv. Candle) were approximately equal in suitability, lamb's-quarters (Chenopodium album) was less suitable, and lentils (Lens culinaris cv. Chilean) was unsuitable as food for M. configurata. The parameters recorded for larval survival, pupal weight, and the number of eggs/female on the most suitable food plants were higher than those recorded previously for larvae reared on excised leaves of suitable hosts.

Mating behavior among many moth species is mediated by female-released pheromones that attract males over distance. Males of the western spruce budworm, Choristoneura occidentalis Freeman, are attracted by pheromone which has been identified and synthesized (Cory et al. 1982; Silk et al. 1982). In response to pheromone, males will fly upwind and thus approach a bait on a fir limb, then land and persistently search near the bait, often locating it (Sower and Shorb 1985). Male budworm moths moving upwind toward a pheromone source are seen to use a wandering, left-and-right and up-and-down flight pattern. This is the classic anemotactic response of male moths to female-released pheromone as described by Shorey (1976), David et al. (1983), and references therein.

Xylosandrus germanus (Blandford) (Coleoptera: Scolytidae) is an ambrosia beetle that occurs in Japan, Korea, the Kuril Islands, Vietnam, Taiwan, China, Central Europe, and the United States (Nobuchi 1981). Unlike most ambrosia beetles, it will attack apparently healthy trees and those that are dying or recently dead (Weber 1982). It has been associated with plants infected with pathogenic fungi, including black walnut (Juglans nigra L.) infected with species of Fusarium (Anderson and Hoffard 1978; Kessler 1974); reported symptoms include cankers, wilting and dieback, and sprouts. We found black walnut with wilting and dieback symptoms in southern Illinois in spring 1978 and central Tennessee in spring 1980. Subsequent examinations showed that X. germanus was present and apparently closely associated with the disease symptoms because of the number of diseased trees that also contained X. germanus pinholes. Therefore, we decided to study the relation between X. germanus attack and disease symptoms in black walnut.

Vol. 117, 1985. pp. 737-762.

p. 745, 1. 7: “Ceraeochrysae placita” should read “Ceraeochrysa placita”.