Baited tree experiments confirmed the hypothesis that frontalin is a multifunctional pheromone that can induce the mountain pine beetle, Dendroctonus ponderosae Hopkins, to aggregate on and mass-attack lodgepole pine, Pinus conforta var. latifolia Engelmann. A re-examination was undertaken of the role of four known semiochemicals, myrcene, trans-verbenol, exo-brevicomin, and frontalin, tested as tree baits alone (with the exception of myrcene) and in all possible combinations. There was considerable redundancy evident in the semiochemical signal. For example, myrcene + frontalin and trans-verbenol + exo-brevicomin induced attack on baited trees at similar levels of intensity. The results suggest that beetles of either sex could initiate a mass attack. During the most attractive phase of host colonization, redundancy in the semiochemical signal could act as a fail-safe mechanism to ensure perception of and response to odors from an attacked tree. In addition the standard, commercial, tree bait containing myrcene, trans-verbenol, and exo-brevicomin might be modified by deleting myrcene, making a more acceptable and cost-effective operational bait.

Descriptions and illustrations of structural features of adults, a key, and chorological data provide the basis for characterizing the genus Ozaena Olivier and classifying the 10 included species, two of which are new: O. maxi (type locality: Iracubo, CAYENNE), and O. manu (type locality: Manu National Park, Madre de Dios Province, PERU). With a geographical range that extends from ca. 30°S to 30°N in the New World, all species of Ozaena occur in cis-Andean South America, only two ranging farther north: O. dentipes Olivier, to Panama; and O. lemoulti Bänninger to southern Arizona, USA. A reconstructed phylogeny postulates the following: the genus Platycerozaena Bänninger as the sister-group of Ozaena, together these genera comprising the Ozaena genus-group; within Ozaena, the O. dentipes group as sister-taxon of the O. lemoulti + convexa groups; within the O. dentipes group, O. maxi as sister-taxon of O. linearis Bänninger + dentipes; within the O. lemoulti group, the sequence O. ecuadorica Bänn. (O. elavata Bänn. [O. lemoulti + martinezi Ogueta]); and within the O. convexa group, O. grossa Bänn. as sister-taxon of O. convexa Bänn. + manu. Character evolution involves losses, gains, and shifts, in about equal numbers. Convergence is relatively rare, involving only three of 35 characters. The predominant mode of character evolution is simple, with few examples of sequential changes sustained through several speciation events. Basic modifications in evolution of the ground-plan of the Ozaena genus-group include reduction or loss (for example, tactile sense organs, antennal cleaner of the fore tibia, and adhesive vestiture of the male fore tarsi), and enhancement or gain (for example, scale-like sensilla basiconica on pronotum and elytra, concentration of sensilla basiconica in groups on the antennomeres, particularly antennomere 11). Within Ozaena, many modifications to the antennae and mouthparts indicate the importance of these organs to evolution of the group.

Based on phylogenetic relationships and the distribution pattern of the extant species, a reconstructed geographical history of Ozaena postulates the following: first, a vicariance event in South America separating the ancestral stock of Ozaena into a northern vicar that gave rise to the O. dentipes group, and a southern vicar that gave rise to the O. lemoulti and convexa groups; followed by cycles of range expansion and contraction that allowed for differentiation of successive stocks of species. The temporal range for these speciation events is estimated to extend over a period of about 12 million years, or from the latter part of the Miocene epoch to the Recent. The most recent speciation events are estimated to be of Pliocene age.

Based on lack of differentiation of South American and Middle American representatives of O. dentipes and O. lemoulti respectively, and extent of range in Middle America, these two species are postulated to be relatively recent invaders of the latter area, with O. dentipes being the more recent to arrive.

The flea beetle, Phyllotreta striolata (F.), was attracted to the cruciferous plants Brassica oleracea L. and Raphanus sativus L., but not to B. campestris L. and B. napus L. which are important natural host plants, nor to Pisum sativum (L.), a legume. The presence or absence of attraction was demonstrated by exposing small groups of caged plants to natural populations and trapping beetles near the plants. In choice and no-choice laboratory feeding experiments, P. striolata fed on eight Cruciferae in the genera Brassica, Raphanus, and Sinapis but not on P. sativum. Phyllotreta striolata fed less on S. arvensis L. and S. alba L. than on plants in the other genera. Within Brassica, B. oleracea, B. napus, and B. campestris were preferred over B. juncea (L.) Czern and B. nigra (L.) Koch. Discrimination at the attraction phase of host selection did not account for discrimination shown in laboratory feeding experiments nor in the natural attack of flea beetles on cruciferous crops.

The black fly species Simulium luggeri Nicholson and Mickel s.l., S. vittatum Zetterstedt s.l., S. venustum Say s.l., S. verecundum Stone and Jamnback s.l., and S. decorum Walker s.l. were collected in silhouette traps near Prince Albert, Sask., in 1986, and near Choiceland, Sask., from 1986 to 1988. The Prince Albert site was located between and within 2 km of the North and South branches of the Saskatchewan River and was 25 and 60 km south of the Whitefox River and Torch River systems. The Choiceland site, 60 km east of the Prince Albert site, was 15 km north of the main branch of the Saskatchewan River and 1/2 and 25 km south of the Whitefox River and Torch River, respectively. Simulium luggeri was the most abundant species collected at the Prince Albert site whereas S. luggeri, S. vittatum, and the S. venustumlverecundum complex were approximately equally abundant in trap catches near Choiceland over the entire season but in each study year a seasonal progression in peak abundance occurred. Black fly numbers in sweep net collections taken once, in the middle of the day, were weakly correlated with numbers in silhouette trap collections taken during an entire day.

The species of Macroneura Walker are revised for America north of Mexico. Seven species are recognized, of which M. camptoptera, M. cerasma, M. chrysosinamora, and M. tanyaris are described as new; M. meteori (Gahan) is removed from synonymy with M. epicaste (Walker) and accorded specific status. Eupelmus melanderi Brues is synonymized with Eupelmus dryorhizoxeni Ashmead and the taxa are reassigned to Eupelmus Dalman from Macroneura. Diagnostic features are given to distinguish females and males of Macroneura from members of other eupelmine genera; putative phylogenetic relationships of Macroneura are discussed, and a key is presented to distinguish females and known males of the North American species.

The oribatid mite genus Megeremaeus is redefined, with the addition of information on leg chaetotaxy and immature instars. Three new species are described, Megeremaeus hylaius from northeastern North America, and M. keewatin and M. kootenai from northwestern North America. Descriptions of the former two species are based on adults and immatures, the latter species on adults only. Nymphs of M. montanus Higgins and Woolley are described. A key is given for the six known species in the genus.

Adult Hoplocampa montanicola Rohwer emerged in mid-May, 6.2 ± 3.2 days (mean ± SE) prior to the period of peak anthesis in Amelanchier alnifolia Nuttall. Oviposition, one egg per flower, occurred during the period of petal drop in late-May; a mean ± SE of 2.2 ± 0.2 eggs were deposited in each inflorescence. Eggs hatched 7.7 ± 3 days (mean ± SE) after the period of primary petal drop and larvae fed on a mean ± SE of 1.8 ± 0.14 fruit per infructescence. Larvae completed development by the end of June, just as the first fruit of A. alnifolia were beginning to ripen. Larvae overwintered in the leaf litter.

Adult Anthonomus quadrigibbus Say (previously assigned to the genus Tachypterellus) were first collected in mid- to late-May during the periods of anthesis and fruit drop in A. alnifolia. Immature fruit fed upon were often extensively damaged. Oviposition occurred toward the end of fruit drop in A. alnifolia, 30.6 ± 2.5 days (mean ± SE) after the period of peak anthesis. Only one egg was laid in a puncture at the base of a fruit. Larval feeding was restricted to ovules and occurred in fruit retained on the plant. Pupation and adult emergence occurred in mid-July as fruit were ripening. The new generation of adults then entered the leaf litter to overwinter.

Neosensoriaphis gen.nov., type-species N. parva sp.nov., Subiziphya gen.nov., type-species S. clauseni sp.nov., and Thripsaphis unciniae sp.nov. are described. The taxonomic position of these aphids is discussed.

From 1976 to 1978, 1300 mated females of Olesicampe geniculatae Quednau and Lim were released near Quebec City during a severe infestation of the mountain ash sawfly, Pristiphora geniculata (Hartig). Both cage and open releases were made. The interactions among the mountain ash sawfly, the imported primary parasite O. geniculatae, and the indigenous hyperparasite Mesochorus globulator (Thunb.), and the effect of O. geniculatae on the host population during and after the establishment phase, are reported. In 1984, O. geniculatae was recovered from all over southern Quebec. Parasitism ranged from 6 to 94%. Concurrently, infestation levels by the mountain ash sawfly declined significantly, and since 1985, the insect has almost disappeared in Quebec. With an annual spread of about 50 km per year after successful establishment, O. geniculatae now covers an area 1000 km in diameter. No major infestation by the mountain ash sawfly has been recorded in Quebec during the past 7 years. The introduction of O. geniculatae is rated as a complete success in classical biological control.

Laboratory bioassays and field tests demonstrated that the (+) enantiomer of endo-brevicomin is an antiaggregation pheromone for the western balsam bark beetle, Dryocoetes confusus Swaine. (+)-endo-Brevicomin significantly reduced the response of beetles of both sexes to the aggregation pheromone exo-brevicomin in laboratory bioassays and in field experiments using multiple-funnel traps. It also prevented attack on subalpine fir, Abies lasiocarpa (Hook) Nutt., trees baited with exo-brevicomin. The (−) enantiomer of endo-brevicomin was inactive. These results suggest that (+) or (±)-endo-brevicomin has potential for protecting selected trees from attack, or suppressing western balsam bark beetle activity in high hazard or infested stands.

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.

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.

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).

Pholetesor ornigis (Weed) from 16 orchards in seven Ontario apple production areas were tested from 1987 to 1989 to determine if their levels of resistance to permethrin and methomyl were higher than those measured earlier in two Ontario populations and if they had developed resistance to azinphosmethyl. Higher levels of resistance were not detected and there was no evidence of resistance to azinphosmethyl. Some possible reasons for the lack of higher levels of insecticide resistance and some alternatives to insecticide resistance for parasite conservation are discussed.

A soil-dwelling predatory mite, Geolaelaps sp. nr. aculeifer (Canestrini), introduced inundatively at a rate of 6000 mites per plant to the sawdust substrate of hydroponically grown, greenhouse cucumbers significantly reduced numbers of fungus gnat, Bradysia spp., larvae and adults over a 10-week period. Inundative introductions of 1600 mites per plant reduced emergence of western flower thrips, Frankliniella occidentalis (Pergande), adults to about 30% of that in the controls over a 40-day trial. An inoculative introduction of 125 mites per plant to cucumber plants in selected rows in a commercial greenhouse reduced peak fungus gnat numbers to about 20% of those in untreated rows. These results suggest that a single inoculative introduction of Geolaelaps sp. nr. aculeifer, early in the crop cycle, would maintain control of fungus gnat populations in greenhouse cucumber crops at an acceptable level. This predator would also contribute to biological control of western flower thrips by reducing emergence of adults.

A systematic analysis of larvae of 11 Nearctic species of Hygrotus Stephens was undertaken. The larvae are described and characterized; a key for their discrimination and illustrations of structural features of representatives of first- and third-instar larvae are provided. Many structural features, especially detailed variations in the chaetotaxy of cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi, were found to be useful for systematic and phylogenetic comparisons. Based on 21 larval characters, a cladistic analysis of the species studied was developed. A sister-group relationship between H. laccophilinus (LeConte) and the remaining available species is suggested. The less derived species, i.e. those without natatory setae on the legs, appear phylogenetically more closely related to the larvae of Hydroporus s.str. Hygrotus masculinus (Crotch) is the most derived species of the genus and, for many characters, seems more closely related to Hyphydrini. According to larval morphology, it is hypothesized that the genus Hygrotus diverged posteriorly to the genus Hydroporus Clairville.

Four different types of insect viruses have been isolated from the eastern spruce budworm, Choristoneura fumiferana (Clem.), but most research efforts have been concentrated on developing the nuclear polyhedrosis virus (NPV) as a viable control agent (Cunningham 1985). There are no published reports of LD50 values for this important forest pest. Recently, a LC50 of 483 viral polyhedra per square millimetre of diet surface for fifth-instar budworm larvae was determined using surface contamination feeding techniques (Cunningham et al. 1983). Because the dosages used in efficacy trials are derived from laboratory LD50 values, experiments were conducted to determine the virulence of this NPV to eastern spruce budworm. Bioassays were conducted with all feeding instars. Reported here are values for the LD50 dosages for third-, fourth-, fifth-, and sixth-instar spruce budworm larvae.

The alfalfa leafcutting bee, Megachile rotundata (Fab.), is an important pollinator of alfalfa in western Canada and is widely utilized for alfalfa seed production (Richards 1984). As a beneficial insect, the alfalfa leafcutting bee must be considered, along with the honey bee, Apis mellifera L., as a non-target organism of importance in evaluations of potential microbial control agents for use against major insect pest species on the Canadian prairies.

From 1981 to 1984, a “looper” complex was responsible for the defoliation of approximately 648 000 ha of hardwood forests in several counties of eastern West Virginia. The complex consisted primarily of four species of Geometridae (Lepidoptera) with larval composition at three study sites in 1983 ranging from 77 to 94% for the half-wing geometer, Phigalia titea (Cramer); 2-13% for the linden looper, Erannis tiliaria (Harris); 8% for Phigalia strigataria (Minot); and 1–2% for the fall cankerworm, Alsophila pometaria (Harris) (Butler 1985a, 1985b, 1986).