Knowledge of the effects of variables that can influence trapping results should help to optimise efforts in exotic species detection and other surveys. Two vertical trap placements (understorey, canopy) were tested to determine influence of these two heights on captures of Scolytinae (Coleoptera: Curculionidae), Cerambycidae (Coleoptera), and Siricidae (Hymenoptera) using semiochemical-baited multiple-funnel traps. Traps were baited with α-pinene, ethanol, ipsdienol, and ipsenol. A total of 8463 insects from 65 species and one genus were captured during the study. Average species richness, species diversity, abundance, number of unique species, and expected diversity were higher in understorey compared with canopy traps. Jaccard (0.94 ± 0.05) and Sørensen abundance (0.97 ± 0.03) similarity indices suggested highly similar communities sampled at the two trap heights. Dendroctonus valens LeConte, Dryocoetes autographus Ratzeburg, Hylastes opacus Erichson, Orthotomicus caelatus (Eichhoff), Gnathotrichus materiarius (Fitch), Asemum striatum (Linnaeus), Monochamus scutellatus scutellatus (Say), Rhagium inquisitor (Linnaeus), and Xylotrechus sagitattus sagitattus (Germar) were more abundant in understorey traps. In contrast, Ips pini (Say), Pityogenes hopkinsi Swaine, Monochamus carolinensis (Olivier), Acmaeops proteus (Kirby), and Astylopsis sexgutatta (Say) were more abundant in canopy traps. The common practice of trapping in the understorey may be optimal for sampling arboreal insects as part of survey efforts. However, additional species may be found by trapping at other vertical placements.

Comparative tests were made in Oregon and Idaho employing sticky traps with three synthetic pheromones of Dendroctonus pseudotsugae Hopkins, frontalin, 3-methyl-2-cyclohexen-1-one, and trans-verbenol, and the host attractants Douglas-fir resin, alpha-pinene, and camphene. The attractiveness of frontalin combined with host volatiles reported earlier from Idaho was confirmed. The combination of trans-verbenol with frontalin plus camphene in Oregon brought the highest response among synthetic treatments, but the addition of trans-verbenol to other treatments with frontalin sometimes decreased beetle response.3-Methyl-2-cyclohexen-1-one almost nullified the attractiveness of all baits tested. The practical use of such a compound to prevent beetle aggregation and protect susceptible Douglas-fir trees as well as to regulate the "spillover" from attractive baits is considered as a possible new method of protection against bark beetles.

The New World species of the staphylinid subfamily Micropeplinae are revised. Three genera are recognized: Kalissus Leconte with 1 species, Micropeplus Latreille with 11 species, and Peplomicrus Bernhauer with 3 species. Of the three previously recognized subgenera of Micropeplus, Arrhenopeplus Koch is placed in synonymy with Micropeplus, and Peplomicrus is elevated to generic status. New species are: M. durangoensis from Mexico, M. neotomae from California and Oregon, M. browni from eastern Canada and the United States, M. robustus from California and Oregon, M. lecontei from southern California, and P. dybasi from Costa Rica and Panama. Micropeplus obliquus Leconte is placed in synonymy with M. sculptus Leconte, and M. oregonensis Hatch is placed in synonymy with M. punctatus Leconte. The genus Micropeplus is divided into six species groups based on an examination of both Old and New World species. A checklist of the species of Micropeplinae places all the described species in the proposed classification. Two African species, M. africanus Cameron and M. carayoni Jarrige, and one Central American species, M. acumen Sharp, are transferred to the genus Peplomicrus.

Data on daily fecundity and survival are presented for the apterous and alate virginoparous morphs of Acyrthosiphon pisum (Harris) reared on broadbean, Vicia faba (var. Exhibition Longpod), at 20 ± 1 °C. Alatae began to reproduce later, and produced fewer young over a longer period than did apterae, but lived no longer.

Reproductive patterns of A. pisum apterae from a number of other clones are compared, and the patterns of some other species are discussed in relation to A. pisum apterae and alatae.

Under favourable conditions some species of insects and mites complete development very quickly. This paper considers species with a mean minimum generation time of 15 days or less and tabulates developmental data for many sample species. Such species belong chiefly to a limited number of taxa of small size, notably aphids and several families of mites and parasitoid Hymenoptera. Characteristics of these taxa are reviewed. Even in families containing many species with rapid life cycles, normally many other species lack such rapid development. Very short life cycles depend on phylogeny, strain, rapid development in all stages, small size, rich food, and other habitat features including high temperatures. Within this framework, life cycles are accelerated by reducing elements requiring the investment of resources (size, fecundity, longevity, structural complexity), eliminating instars and even life stages, accelerating development (through lower requirements especially of heat, heat gain by adaptations such as basking, and rapid reproduction), and choosing the most suitable habitats and microhabitats from those available. Mean minimum generation times in insects and mites with coincident adaptations of this sort can be as short as 4 days. Notwithstanding the advantages of rapid development in maximizing the intrinsic rate of natural increase (and hence fitness), most species cannot achieve the highest rates of development. They are constrained not only by resources and intrinsic physiological or phylogenetic patterns but also by variability of conditions and seasonality that can be survived only by interpolating delays or resistant stages.

This paper is an account of the distributions of the Anthocoridae of the Pacific Northwest (British Columbia, Washington, Oregon, and Idaho), with notes on the life histories of the more common species. It brings together the published and unpublished data on the family in that area. Seven species listed were previously unrecorded there and five others are new species recently described (Kelton and Anderson, 1962). In 1956 and 1957 intensive collecting was done in southern British Columbia and some material was collected in the Willamette Valley and east of the Cascade Range in Oregon. Specimens were examined in the important museum collections of the area and in some private collections.

The daily patterns of activity of females of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin), were observed in controlled laboratory conditions and in field conditions in eastern Saskatchewan in mid-July 1986 and 1987. In the field, during the daytime, females rested on stems of wheat plants within 30 cm of the ground and, at approximately 2000 hours CST, flew up to wheat heads. Most oviposition took place between 2000 and 2145 hours (or 75 min before, to 30 min after, sunset). Toward the end of the oviposition period, females were frequently seen drinking dew from wheat heads. On some evenings, females migrated down from the heads following oviposition, but on more than half of the evenings they remained on the heads until early morning. However, they never moved down to the low level they occupied during the day until the next morning, when the migration was usually complete by 0900–1000 hours. Light intensity appeared to regulate the vertical migration of females. Cloudy conditions may allow an earlier onset of oviposition. Flight was limited to air temperatures above 14–15 °C and oviposition to temperatures above 10–11 °C. Wind speeds of 10 km per h or more and rain occasionally limited activity. In the laboratory, oviposition activity occurred almost exclusively during the scotophase, mainly in the first 2 h. Mean total fecundity was 83.6 ± 10.9 (±SE) eggs, and mean longevity was 6.6 ± 0.6 days. No oviposition took place on the 1st night, and the greatest mean daily fecundity occurred on the 3rd night.

Oviposition and post-oviposition behavior of Telenomus fariai Costa Lima, when parasitizing the eggs of Triatoma phillosoma pallidipennis Stål, is described. Like other egg parasites T. fariai marks hosts by rubbing the ovipositor against the host and transferring a water soluble pheromone (chemical nature unknown) to its surface. Females that had never parasitized largely ignored the mark. Females that had parasitized generally did not oviposit on a marked host. The mark was fully effective for at least 3 days after being applied. The function of egg marking by T. fariai is discussed.

Detailed studies on the population dynamics of the imported cabbageworm, Pieris rapae (L.), have been carried out at Merivale, Ontario, since 1959. A method for preparing life tables is described and a mean life table is presented for 18 generations of the species on cabbage. Population data for the preadult period show that there are three age intervals during which extensive mortality may occur: (1) between hatching and the second moult, (2) instars three to five, and (3) during the pupal stage. The analysis of successive age-interval survivals in relation to generation survival showed that the latter is largely determined by the survival rate for (2). Examination of the life tables revealed that a granulosis of the larvae caused by a capsule virus is the key factor in generation survival. Major mortality factors include rainfall and parasites.

Though they may hatch on any part of a housefly (Musca domestica L.) pupa, most larvae of Nasonia vitripennis (Walk.) and Muscidifurax raptor G. & S. (Hymenoptera: Pteromalidae) move to the host’s ventral abdominal area, and those of Spalangia cameroni Perk. (Hymenoptera: Pteromalidae) to the dorsal side of the abdomen, before feeding extensively. As many as 25 larvae of N. vitripennis can mature on a medium-sized housefly pupa; if more are present initially, those that hatch last usually die from starvation after the host has been consumed. In contrast, usually only one larva of M. raptor or S. cameroni matures on a host; this is often the larva that hatches first, because it attacks all parasite eggs that it encounters while moving over the fly pupa soon after hatching. Larval crowding in M. raptor or S. cameroni, unlike that in N. vitripennis, does not affect the sex ratio of the survivors.

Individuals of Umbonia crassicornis Amyot and Serville (Homoptera: Membracidae) form aggregations both as nymphs and adults. Each adult female deposits one set of eggs and remains with them. Prior to egg hatching the female moves off the egg mass and makes a series of spiral bark slits with the ovipositor. First instar nymphs aggregate along these slits with the female positioned below the cluster. Adult females use the front tarsi to stroke the backs of moving nymphs to return them to the aggregation.

Adult females remain with the nymphs until they become adults. Aggregations of adults fragment when sexually mature; mating takes place before and during dispersal. Mating behavior consists of four components, the precopulatory position being prolonged.

A method is described for partitioning normal plant fruit shedding losses from those caused by the pest Lygus hesperus Knight. The relationship between age of bug and its damaged rate per day degree was determined, and used to assess the impact of various lygus population levels on crop development and yield. A simulation model for lygus phenology and population dynamics is reported.

The antiaggregative pheromone 3-methyl-2-cyclohexen-1-one (MCH) of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopk.) was diffused at three rates and three spacings around attractive felled trees. Optimum treatment was ca. 1–2 mg/day at 10-ft spacing (0.06–1.3 g/acre per day), which reduced Douglas-fir beetle attacks and progeny by 96% and 91%, respectively. Progeny in trees exposed to higher than optimum MCH concentration were less mature, but not significantly fewer than progeny in controls. Densities of immature stages of nine other taxa of insects, both entomophagous and commensal, were determined. Abundance of larvae of the predacious clerids Enoclerus sphegeus Fab. and Thanasimus undatulus Say was significantly correlated with abundance of Douglas-fir beetle attacks and progeny. The predator Temnochila chlorodia (Mann.) and the associate Pseudohylesinus nebulosus (Lee.) were more dense on samples in the test area where Douglas-fir beetle population and damage were lowest. Density of the dipterous predator Medetera aldrichii (Wheeler) was correlated with numbers of beetle entrances, but decreased at high MCH concentrations. Abundance of Coeloides brunneri Vier., a braconid parasite, was correlated with numbers of beetle brood. Presence of MCH appeared to increase abundance of the associate Pissodes fasciatus Lec. and modify its distribution in trees. Use of methylcyclohexenone for preventing infestation of susceptible trees is a potential control strategy, but a more practical and effective formulation must be developed.

The western flower thrips, Frankliniella occidentalis (Pergande), occurs from sea level to subalpine altitudes in western North America (Bryan and Smith 1956). Until recently, it was assumed that this species was found primarily west of the Rocky Mountains and that Frankliniella tritici (Fitch), the eastern flower thrips, was the dominant flower thrips in both eastern Canada and United States. Beshear (1983) reported F. occidentalis on cotton, peas, beans, and peanuts in Georgia. The following year, in the Niagara Peninsula of Ontario, the tomato spotted wilt virus caused extensive crop losses to greenhousegrown tomatoes and ornamentals. The virus-vector was identified as F. occidentalis (Allen and Broadbent 1986). Previously, F. fusca was the only known vector of tomato spotted wilt virus in Ontario and the eastern provinces (Paliwal 1974, 1976).

Bees are important within terrestrial ecosystems, providing pollination, which facilitates plant reproduction. Agricultural regions are large landscapes containing varying proportions of cropland, natural, and semi-natural habitats. Most bees are not restricted to any of these and move freely throughout, exploiting food and nesting resources in favourable locations. Many factors affect bee diversity, and knowledge of these is crucial for promoting healthy bee communities. The main objectives of this study were to compare diversity and guild structure of bee communities across a range of land disturbance levels within the Annapolis Valley, Nova Scotia, Canada, in habitats ranging from managed apple orchards to old fields. The two habitat extremes differed significantly; intensely managed orchards had significantly lower species richness (∼50%) than observed/estimated in old fields, but orchards with intermediate levels of adjacent natural/semi-natural habitat showed affinities to either extreme depending on the metrics used for estimating species richness. Species assemblages in orchards had lower proportions of several guilds, particularly cavity-nesters, bumble bees, and cleptoparasites, than other habitats. These guilds accounted for over 30% of bees collected in old fields but only 3–10% in orchards, increasing with habitat complexity. The use of guilds for assessing the health of bee communities is discussed.

Leaves were collected between 28 July and 10 September from 36 (1986) and 85 (1987) apple orchards, and examined for mites. Twelve species of Phytoseiidae were found: Amblyseius fallacis (Garman), Typhlodromus longipilus Nesbitt, A. andersoni (Chant), T. caudiglans Schuster, T. pyri Scheuten, T. pomi (Parrott), Phytoseius macropilis (Banks), T. herbertae Chant, A. driggeri Specht, A. finlandicus (Oudemans), T. conspicuus (Garman), and A. pusillus (Kennett), in order of frequency. The stigmaeid mites Zetzellia mali (Ewing) and Agistemus fleschneri Summers, a complex of erythraeid mites of Balaustium spp. and Hauptmannia spp., and tydeid mites, primarily Tydeus spp., were other common predatory species. Species of Tetranychidae, Bdellidae, Eriophyidae, Winterschmidtiidae, and Tarsonemidae, also were collected.

Predatory mites were present each season in all abandoned orchards and in 43–74% of the commercial orchards. Their abundance in commercial orchards was compared with the use of insecticides applied only for control of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.). Fewer (P < 0.05) phytoseiids occurred where pyrethroids were employed than in sites without pyrethroids, but differences were not found for similar use of the carbamoyl oxime, methomyl. Fewer (P < 0.05) stigmaeids occurred in sites treated with methomyl than in sites without methomyl, whereas such differences were not found for pyrethroid use.

Most major modern families of Hymenoptera were established in the Mesozoic, but the diversifications within ecologically key trophic guilds and lineages that significantly influence the character of modern terrestrial ecosystems – bees (Apiformes), ants (Formicidae), social Vespidae, parasitoids (Ichneumonidae), and phytophagous Tenthredinoidea – were previously known to occur mostly in the middle to late Eocene. We find these changes earlier, seen here in the early Eocene Okanagan Highlands fossil deposits of western North America. Some of these may have occurred even earlier, but have been obscured by taphonomic processes. We provide an overview of the Okanagan Highlands Hymenoptera to family level and in some cases below that, with a minimum of 25 named families and at least 30 when those tentatively assigned or distinct at family level, but not named are included. Some are poorly known as fossils (Trigonalidae, Siricidae, Peradeniidae, Monomachidae), and some represent the oldest confirmed occurrences (Trigonalidae, Pompilidae, Sphecidae sensu stricto, Peradeniidae, Monomachidae, and possibly Halictidae). Some taxa previously thought to be relictual or extinct by the end of the Cretaceous (Angarosphecidae, Archaeoscoliinae, some Diapriidae) are present and sometimes abundant in the early Eocene. Living relatives of some taxa are now present in different climate regimes or on different continents.

The statement of Criddle (1917) that grasshopper outbreaks are associated with periods of dry weather has been repeated by many authors, but a close relationship has never been demonstrated.

Parker (1933) showed that at six localities in the United States grasshopper outbreaks during the period 1915-1933 had been preceded by periods of two to four years when either rainfall had been below normal during May-June or temperature had been above normal during July-September. Similarly Smith (1954) concluded that between 1910 and 1953 outbreaks in Kansas had been preceded by two years of sub-normal rainfall. Parker's charts show that grasshopper outbreaks generally followed periods of hot weather, but the charts of both authors show that only about half the time did outbreaks follow periods of dry weather – a situation that could be largely due to chance.

MacCarthy (1956) calculated the correlation coefficients between weather factors and populations of M. bilituratus (Walker) in five large areas of Saskatchewan during the period 1943-1952. His tables show generally insignificant correlation with total precipitation and only with mean minimum monthlv temperature in June of the previous year was there significant correlation in all five areas.

The present investigation was undertaken in an attempt to determine whether a sufficiently close relationship between grasshopper populations and climate could be found for use in predicting grasshopper outbreaks.

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.