Cymodusa borealis sp.nov. (Hymenoptera: Ichneumonidae) is described from the Canadian arctic. This species belongs to the cruentata group of Cymodusa Holmgren (sensu Sanborne 1986).

Psallus salicicola sp.nov. is described from northern Canada. Dorsal habitus and male genitalia illustrations are included. Psallus aethiops Zetterstedt is considered to be the senior synonym of P. drakei Knight. Additional distributional records are given for P. aethiops and P. betuleti (Fallén) from Alaska and northern and maritime Canada, which indicate that these two species are genuinely Holarctic taxa.

The arthropod and annelid fauna of a series of small, acidic pools in a domed, ombrotrophic bog on the Avalon Peninsula, Newfoundland, was studied over the ice-free season of 1986. Pools were assigned to four classes on the basis of their surface area (<1; 1.1–10; 10.1–100; >100 m2) and at least two 1-m2 (entire pool if area <1 m2) substrate samples, plankton samples, and moss samples were taken from pools of each size class biweekly. One hundred and thirty-one taxa, most identified to the species level, were collected. Taxa varied in abundance between pools of various size classes and, using Cluster Analysis and TWINSPAN, two principal communities were identified. Oligochaetes, beetles, and mosquitoes dominated small, astatic pools and odonates, chironomids, and several other taxa predominated in large, stable, vegetated pools. Water level stability is postulated to be the principal factor determining this community structure. Within large pools, odonate larvae were the dominant predators and comprised the majority of the standing crop. Odonate larvae have life cycles of 2 or more years; their slow growth is probably due to prey limitation. Odonate larvae potentially exert a powerful predation pressure within the large pool community, and may be the principal biotic factor determining abundance and distribution of prey taxa within the bog pool system.

Nine entomopathogenic nematode–bacteria complexes were screened for their virulence against larvae of six noctuids, a geometrid, and a pyralid. Ninety-six-hour LD50’s of steinernematids (and heterorhabditids) ranged from 1 to 3 (1–8) infective juveniles in Galleria mellonella (L.), 1–71 (2) in Peridroma soucia (Hbn.), 1–10 (1–3) in Mamestra configurata (Wlk.), 1–28 (3–7) in Euxoa ochrogaster (Gn.), 19 in Lacanobia radix (Wlk.), 22–60 (4) in Pseudaletia unipuncta (Haw.), 2–95 (111) in Agrotis ipsilon (Hufn.), and 3–28 in Paleacrita vernata (Peck). The nematode, Steinernema feltiae LIC, a cold-hardy strain isolated in Newfoundland, was highly virulent for G. mellonella and M. configurata, but not for P. soucia and E. ochrogaster. The number of nematodes invading larvae and the number produced were greater in G. mellonella than in other insects tested. Nematode–bacteria complexes that showed potential for controlling cutworms included S. feltiae, S. glaseri, S. bibionis, Heterorhabditis bacteriophora, and H. heliothidis.

Solanum berthaultii Hawkes bears trichomes reportedly providing resistance to insects. Results indicated that the density of types A and B trichomes was linearly related to the inverse of the leaflet area. The number of trichomes on the adaxial and on the abaxial surface of terminal leaflets was not affected by two levels of water stress or by growing conditions in the greenhouse or the field. The leaflets of the water-stressed plants were generally smaller and, consequently, the density of trichomes higher.

The survival of first-instar Colorado potato beetle larvae was similar on S. berthaultii grown under varying drought conditions and on leaves from field-grown plants bearing different densities of trichomes.

The Eurasian noctuid, Calophasia lunula Hufn., was introduced into North America to control yellow toadflax, Linaria vulgaris Mill., and Dalmatian toadflax, L. genistifolia ssp. dalmatica (L.) Maire and Petitmengin. Larvae feed on the foliage of both toadflax species, but different strains of the moth appear to prefer either yellow or Dalmatian toadflax (Nowierski 1990). Calophasia lunula was first released against yellow toadflax in five Canadian provinces from 1962 to 1968 (Harris and Carder 1971). The moth has been established on yellow toadflax in Ontario since 1965, where it has defoliated up to 20% of the stems (Harris 1988). However, attempts to establish C. lunula on Dalmatian toadflax in Canada have been unsuccessful (Nowierski 1990). Initial releases of the moth in the United States were made in 1968 against both toadflax species with Ontario stock from yellow toadflax (Nowierski 1990). Since then, multiple releases of C. lunula have been made in six western states, including Montana (Story 1985), but until 1989 no establishment had been recorded on either toadflax species.

Sinophorus wushensis sp.nov. (Hymenoptera: Ichneumonidae) is described from Taiwan. This is the first verified record of Sinophorus from Taiwan.

Although the role of phytoseiid mites as predators of the European red mite, Panonychus ulmi (Koch), on apple is well established, the role of another family of European red mite predators, the stigmaeids, is not as clearly understood. We compared predatory behavior and prey-stage preferences of the stigmaeid Zetzellia mali (Ewing) and the phytoseiid Typhlodromus caudiglans (Schuster) in the laboratory. The only predator–predator interaction we found to be potentially important was consumption of phytoseiid eggs by stigmaeids. Given a choice of equal numbers of both European red mite eggs and phytoseiid eggs, Z. mali consumed 38% phytoseiid eggs. Eggs and quiescent larval stages of European red mite were preferred by Z. mali, but active larval stages also were consumed. By contrast T. caudiglans preferred active forms to quiescent forms and eggs, and was able to consume adult forms. Although Z. mali was found to be slower, less active, and less voracious than T. caudiglans, Z. mali produced more eggs for a given number of prey consumed than did T. caudiglans. These behavioral and prey-stage preference differences should enable phytoseiids and stigmaeids to be compatible in the short term (within one generation).

Omalonomus relictus, a highly modified new genus and new species of soil-dwelling rove beetle, is described from the Cypress Hills of Alberta and Saskatchewan. The structural peculiarities associated with its subterranean habitat are discussed and illustrated. Moore and Legner’s (1974) key to the genera of North American Omaliinae is modified to assist in the identification of adults of the genus. The occurrence of this blind, slightly pigmented, flightless beetle in the soil of the Cypress Hills supports the hypothesis that at least part of this area was unglaciated and served as a refugium during late Pleistocene glacial advances.

Podisus sagitta (Fab.) is a small- to medium-sized predatory stink bug, which is distributed from the southern United States into South America. The immature stages and both sexes of the adult insect from a laboratory strain are described and illustrated. Notes on the life history of P. sagitta also are given.

Populations of pea aphid, Acyrthosiphon pisum (Harris), were sampled through the summer of 1984 on five cultivars and in 1985 and 1986 on six cultivars of field peas, Pisum sativum L., grown in field plots in southern Manitoba. Patterns of pea aphid population growth were generally similar among cultivars in any one year. Aphid populations on all cultivars in all years remained relatively low until mid-July, then increased rapidly, peaked at about the beginning of August, and declined sharply to low levels in late August. At the time of peak aphid numbers, significant differences in aphid population densities were found among cultivars in 2 years; the lowest densities were found on the cultivars Century and Tipu, and the highest densities on Triumph or Trapper. Pea aphid feeding was not detrimental to any yield parameters except 1000 seed weight. In 1984 Triumph and Tara, and in 1985 Triumph had significantly decreased 1000 seed weights in plots in which aphid densities were not controlled. Differences in the abundance of the aphid among cultivars were not reflected in their yield responses. Over 3 years the regression line of aphid densities upon Century seed weight was significantly steeper than those of Trapper, Lenca, or Tara. Trapper was least affected by aphid feeding. Results indicated that the economic threshold of pea aphids on peas other than Century needs to be re-evaluated.

Relationships between temperature and development rates of eggs and larvae of Winthemia fumiferanae Toth. were experimentally determined, using the spruce budworm as host. Hatching of parasitoid eggs was triggered by host pupation. The median time required to complete egg development at different temperatures was estimated from distributions of percentage development success of the parasitoid over time between egg deposition and host pupation. For parasitoid eggs that had sufficient time to hatch, detachment from the host before pupation was the most important cause of mortality at 15 °C or higher, but was negligible below this temperature. A curvilinear model describing egg development rate as a function of temperature was used to simulate the development of W. fumiferanae eggs in the field. The relationship between larval development rate and temperature also was modelled, and the variability described. Simulations initiated by host pupation-driven egg hatching, and terminated with prepupal drop to the ground, are presented and discussed with respect to the appropriateness of using host pupation as an indicator of parasitoid egg hatching in the field.

A non-pest population of Colorado potato beetle, Leptinotarsa decemlineata (Say), was monitored in the field and in the laboratory to define some cultural and host plant factors that might prompt increased use of potato by a population locally adapted to a wild host species (Solanum sarrachoides Sendt.). This study tested whether elimination of the beetle’s natural host from plots of potato would result in increased densities of beetles on potato, and examined whether beetles showed differences in performance on and in preference for S. sarrachoides or potato. In 2 years of study, egg densities on potato were higher in weed-free than weedy plots; paired preference tests in the laboratory also indicated that beetles deposited the most egg masses (92%) on S. sarrachoides. Densities of larvae and adults on potato were not affected by weed density. Growth rates of larvae were significantly faster on S. sarrachoides than on potato for both early-season (pre 7 July) and late-season (post 21 July) foliage. Survival and adult size were not affected by host species. In choice tests, late-instar larvae preferred S. sarrachoides to potato. Host preference of larvae varied with age of foliage, and S. sarrachoides became increasingly preferred later in the growing season.

One or more insects were captured during 1 week in probe traps placed in granaries holding wheat, barley, or oats in 51% (n = 116) of grain bulks in the fall of 1986, 88% (n = 111) in the summer of 1987, and 85% (n = 106) in the fall of 1987. Fungivorous insects were the most common and predominant group at all sampling times. Granivorous species were the rusty grain beetle, Cryptolestes ferrugineus (Stephens), and the red flour beetle, Tribolium castaneum (Herbst). Grain in galvanized steel and wooden granaries was usually infested with insects to the same extent; granaries with or without aeration systems usually contained the same number of species; small bulks of grain often were infested less frequently than large bulks; the presence of livestock feed on farms did not result in greater insect incidence; and insecticide use in granaries did not prevent re-infestation of grain and insecticide use increased from 24% in 1986 to 31% in the fall of 1987. The kinds of insects detected in grain stored with various farming practices, and co-occurrence with other arthropods in the grain provides baseline information on potentially changing patterns of infestation.

Pitch canker, caused by Fusarium subglutinans (Wollenw. and Reink.) Nelson, Toussoun, and Marasas, a pine pathogen recently identified in California, may increase the distribution and abundance of Ips spp. on Monterey pines in Santa Cruz Co., CA. In all pine stands, Ips spp. tunneled into healthy branches and boles. Ips mexicanus (Hopkins) was the most abundant engraver beetle observed, followed by I. paraconfusus Lanier; I. plastographus (LeConte) was rare. Ips mexicanus was routinely captured in traps baited with racemic I. paraconfusus pheromone. During die winter, I. mexicanus excavated mass feeding cavities in shade-suppressed branches. In uninfected stands, 3% of the trees and only 0.3% of the branches were mass-attacked. In severely infected stands, 47% of the top one-third of the trees, 3% of all branches, and 91% of the branches declining due to infection by F. subglutinans were mass-attacked by Ips spp. On pitch canker-infected trees, I. mexicanus attacked cones and stems <1 cm in diameter. Sixty percent of the attacks on logs occurred inside or within 5 cm of the area covered with pitch canker-induced resin. When confined with logs, 45% of I. paraconfusus tunneled in or near pitch canker-induced resinous areas,21% near fresh chisel wounds, and 19% near resinous material produced by the Sequoia pitch moth. Synanthedon sequoiae (Hy. Edwards).

Pectinmethylesterase (PME) activity was found in the salivary glands of nymphs and adults of a leaf-footed bug, Leptoglossus occidentalis Heidemann. Puncture wounds in cone scales resulting from PME activity in the saliva of these bugs were seen by staining with a 0.05% aqueous solution of ruthenium red. This staining technique can be used to estimate feeding damage by L. occidentalis on cones of western white pine (Pinus monticola Dougl.), sugar pine (P. lambertiana Dougl.), and Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco).

Summary life table data of historical spruce budworm, Choristoneura fumiferana (Clemens), populations from the Green River Project in New Brunswick, Canada (1947–1958), provided information for developing a management strategy using annual inundative releases of the egg parasite Trichogramma minutum Riley. Three threshold levels (39, 169, and 201 budworm egg masses per 10 m2 foliage) were assigned to the spruce budworm population and a simulation model employed to manage it at or below each level. Based on field data, the lowest threshold represented a light level of defoliation while the other two thresholds represented moderate defoliation levels. With the exception of 3 years at the low level, annual inundative releases of T. minutum successfully suppressed the spruce budworm population below the three thresholds in the model. Annual releases of T. minutum were also simulated during the inclining, plateau, and declining phases of one outbreak cycle of the spruce budworm. At the same rate (12 × 106 female T. minutum per hectare), inundative releases during the inclining phase were more effective than during either the plateau or declining phases. The results suggest that some low and moderate populations of spruce budworm can be effectively managed using annual inundative releases of an egg parasite, particularly toward the end of the inclining phase of an outbreak, but when populations reach severe levels, additional mortality agents probably will have to be considered in an integrated approach.

Incidence of the western pine shoot borer, Eucosma sonomana Kearfott, and tree growth measurements from 5687 ponderosa pines, Pinus ponderosa Dougl. ex Laws., were recorded in the Calf Pen plantation Payette National Forest, ID. The percentage of trees infested by shoot borer generally increased as tree height increased.

Infestation of the tree’s leader usually resulted in reduced height growth especially where needle length was shortened in the leader. Height growth of infested leaders was less than uninfested leaders. This difference in height growth increased with the total height of the tree as measured in the previous year.

The accuracy of visual observations in estimating numbers of tuber flea beetles, Epitrix tuberis Gentner, on young potatoes was determined. Potential sources of observational error examined were as follows: (a) observer competence and experience; (b) time spent observing each plant; (c) time of day; (d) plant height; and (e) weather. Observational accuracy versus tuber flea beetle density on plants followed a linear relationship for both experienced and inexperienced observers. Marked differences between experienced and inexperienced observers generally were reduced after 2 h of sampling experience, but some observers were consistently less accurate at sighting beetles than others. When observing small plants, 5-s observations generally were more accurate at sighting beetles per second of observation than 2-, 8-, or 10-s observations. Under uniform weather conditions, accuracy was the same in the morning as in the afternoon. Observer accuracy was significantly reduced under the combined influences of observer fatigue and wind. The relationship of 5-s-per-plant sampling accuracy to plants between 14 and 56 cm in height was linear; however, a quadratic relationship is suspected for plants over the full range of plant heights (i.e. >1 cm). From these data, total tuber flea beetles per plant estimated by 5-s visual observations per plant would be: TFB = TFB0/EhE0n where TFB0 is the total number of flea beetles observed, n is the total number of plants sampled, Eh is a sampling accuracy constant for the mean plant height sampled, and E0 is the observer accuracy constant calculated as a proportion of the most proficient observer(s).

Carabid beetles were collected using pitfall traps and tree bands in forest stands in southwestern Pennsylvania subjected to defoliation by gypsy moth for the first time. Some of the stands were treated aerially with Bacillus thuringiensis Berliner (B.t.). The guts of all carabids collected were tested for the presence of gypsy moth proteins using the ELISA technique. Twenty-seven of the 33 species (82%) collected from pitfall traps, and four of the seven species (57%) collected under tree bands, tested positive. Of the 1142 individuals from pitfall traps and 73 individuals from tree bands, the percentages positive were 45 and 38%, respectively. Calosoma frigidum Kirby had the highest percentage positive (78%) of any species. Statistically significant differences in percentages positive between B.t.-treated and untreated plots were found only for Pterostichus mutus Say and P. coracinus Newm., and when all species were combined. The presence of nucleopolyhedrosis virus in the gypsy moth population was unanticipated and may have influenced these results through increased feeding on carrion.