The amount of wax on leaf surfaces was determined for waxy and low-wax phenotypes of three Brassica crops: oilseed rape, kale, and collards. The effects of these phenotypes were assessed on the fecundity, settling time, and biomass increase of the mustard aphid, Lipaphis erysimi (Kaltenbach), a pest of oilseed rape. Leaves of the waxy phenotype of each Brassica had about twice as much wax as the low-wax phenotype, but the amount of wax had no effect on any of the three measures of aphid performance. Lipaphis erysimi was more fecund and produced a higher biomass on the rape than on the collards, but settled more quickly on the collards than on rape. If the waxiness of oilseed rape is altered to increase crop resistance to other pests, the pest status of L. erysimi is unlikely to be affected.

The predatory gall midge, Aphidoletes aphidimyza (Rondani 1847), is a biological control agent used worldwide to control aphids. Mass-production methods are well established in Canada, the Netherlands, England, Germany, Finland, and the former U.S.S.R. (cf. van Leiburg and Ramakers 1984). In early March 1991, after 6 years of massproduction of A. aphidimyza on a rapidly increasing scale, two minute adult hymenopterous parasitoids were observed eclosing from a sample of pupae at a commercial insectary in British Columbia. It is likely that the founding parasitoid individual(s) entered the greenhouse before winter, as parasitoids appeared too early in the year to have entered from outdoors at that time.

The Ochlerotatus communis (De Geer, 1776) complex consists of four cryptic mosquito species in North America, including: O. communis, Ochlerotatus churchillensis (Ellis and Brust, 1973), Ochlerotatus nevadensis (Chapman and Barr, 1964), and Ochlerotatus tahoensis (Dyar, 1916). Most of the morphological characters used for the identification of these species are quantitative and overlap across species. Here we evaluated the efficacy of DNA barcoding for identification of three members of the communis complex (O. nevadensis is not included in this study) and developed diagnostic restriction fragment length polymorphism (RFLP) patterns for O. communis and O. churchillensis. A phylogeny of 23 Ochlerotatus Lynch Arribálzaga, 1891 species was inferred using mitochondrial cytochrome c oxidase subunit I gene sequences. All species included in our analysis within the O. communis complex were delineated using cytochrome c oxidase subunit I barcodes. However, this complex was recovered as paraphyletic with respect to Ochlerotatus abserratus (Felt and Young, 1904) and Ochlerotatus implicatus (Vockeroth, 1954), indicating the need for increased genetic and taxonomic sampling to infer the phylogenetic relationships of these taxa. The RFLP profile for multiple field specimens of O. communis was distinct from all RFLP patterns for O. churchillensis, and this method can be used as an efficient molecular method for the identification these species.

We describe the first dragonflies (Odonata: Anisoptera) from the early Eocene Okanagan Highlands of far-western North America from nine fossils. Six are assigned to five species in four new, named genera of Aeshnidae: Antiquiala snyderaenew genus and species, Idemlinea versatilisnew genus and species, Ypshna brownleeinew genus and species, Ypshna latipennatanew genus and species, and Eoshna thompsonensisnew genus and species; we treat one as Aeshnidae genus A, species A; one is assigned to Gomphidae: Auroradraco eosnew genus and species; and we treat a ninth, fragmentary fossil of unknown family affinity as Anisoptera indeterminate genus A, species A, which represents a seventh genus and eighth species. The dominance of Aeshnidae is consistent with other Paleocene and Eocene fossil localities. Auroradraco eos is the only fossil Gomphidae in the roughly 66-million-year gap between occurrences in mid-Cretaceous Burmese amber and the early Oligocene of France. Ypshna appears close to Parabaissaeshna ejerslevense from the early Eocene Fur Formation of Denmark; this is not surprising given Holarctic intercontinental connections at this time and a growing list of insect taxa shared between the Okanagan Highlands and the Fur Formation.

Six subspecies of Bacillus thuringiensis Berliner (Bt) were grown in minimal medium with chitin as the sole carbon source for 6 days to obtain Bt cell-free fermented broths, which were then evaluated for chitinolytic activity and tested against third-instar Aedes aegypti (L.) (Diptera: Culicidae) larvae. Bt pakistani showed the highest chitinolytic activity (approximately >2700 mU/mL), Bt kurstaki showed the lowest activity (approximately <2000 mU/mL), and Bt thompsoni, Bt aizawai, Bt israelensis, and Bt alesti showed intermediate activities (approximately 2100–2400 mU/mL). Bt aizawai and Bt thompsoni broths showed the highest toxicity (LC50) against third-instar A. aegypti larvae (approximately <290 mU/mL). Bt kurstaki broth showed the lowest toxicity (approximately 420 mU/mL), while Bt pakistani, Bt israelensis, and Bt alesti broths showed intermediate toxicities (approximately 360–460 mU/mL). A purified and biochemically characterized Bt aizawai chitinase and commercial chitinases (from Serratia marcescens Bizio and Streptomyces griseus Waksman and Henrici) were evaluated and compared for synergistic effects on Bt israelensis spore-toxin complex against third-instar A. aegypti larvae. The synergism factor value of Streptomyces griseus and Bt aizawai chitinases were >2 and approximately 1.4; synergism was not evident for the Serratia marcescens chitinase (synergism factor value approximately 0.9).

Circulifer tenellus (Baker) has a mean preoviposition period of 13.1, 8.2, 6.4, and 5.0 days when held at 20, 25, 28, and 32°C, respectively. The fecundity of C. tenellus averaged 105.0, 98.9, 115.7, and 196.9 eggs per female when held under the same temperatures, respectively. The longevity of the adult C. tenellus females when held under constant conditions of 20, 25, 28, and 32°C averaged 58.1, 52.7, 41.9, and 44.8 days, respectively. Fluctuating temperatures of 19–36°C under greenhouse conditions resulted in a mean preoviposition of 10.7 days and a fecundity rate of 163.4 eggs per female with females living an average of 96.3 days with a longevity range of 142 days.

Although the spruce budworm, Choristoneura fumiferana (Clemens), has received much attention as a result of its economic importance, little is known about its internal morphology and development. In this paper some features of the embryonic development will be described and compared with those of other Lepidoptera.

Two new species, Micropeplus volcanus from Mexico and M. smetanai from British Columbia, are described and illustrated. New distributional and habitat data are given for nine other species of the subfamily. The male genitalia of Kalissus nitidus Leconte and Peplomicrus acumen (Sharp) are illustrated for the first time. A revised key to the New World species of the genus Micropeplus is presented.

The species of the genus Tachinomorphus (Staphylinidae: Tachyporinae) of North and Central America are revised. Five species are recognized as valid. Two species are described as new: arizonensis from the Huachuca and Chiricahua Mountains of Arizona and Durango in Mexico and sharpi from Texas and northern Mexico. Tachinomorphus remotus (Sharp) is placed in synonymy with grossulus (Leconte). Lectotypes are designated for grossulus (Leconte), remotus (Sharp), and major (Sharp). The distribution of each species is mapped and all major diagnostic characters illustrated either with line drawings or scanning electron photomicrographs. The habitat, if known, is discussed for each species. A key is included as an aid to distinguishing the species.

The Colorado potato beetle, Leptinotarsa decemlineata (Say), overwinters in the soil as a diapausing adult. Large numbers of adult beetles fly and walk from potato, Solanum tuberosum L. (Solanaceae), fields to the surrounding forested edges late in the summer (Voss and Ferro 1990). This movement can result in higher densities of diapausing adults in the soil along these edges than in potato fields (Weber and Ferro 1993). Beetles that overwinter in these woody borders show lower levels of overwintering mortality (Weber et al. 1994). Survivorship of overwintering Colorado potato beetle adults was positively correlated with soil depth for studies conducted adjacent to potato fields in New Jersey (Lashomb et al. 1984) and Massachusetts (Weber and Ferro 1993). Lashomb et al. (1984) reported that a 10-cm increase in soil depth decreased winter mortality by 32%.

Twenty-two species of insect parasites of Fenusa pusilla (Lepeletier) are listed. Fifteen of these species were reared in the present study from F. pusilla in Quebec, 1 on eggs and 14 on larvae; 4 of them act as both primary and secondary parasites. Of the 15, only 1 has previously been reported as a parasite of F. pusilla. Host–parasite relationship and the degree of parasitism are given for the 15 species reared in Quebec.Thirteen species of predators are listed. Of these, 9, three birds and six insects, were observed feeding on F. pusilla larvae during this study.

A technique is described whereby an average of 99% (96–100%) of known numbers of eggs of Ctenicera destructor (Brown) were removed from units of soil 1/2 pint in volume. Average time to process each unit was 11/2 man-hours.

Larvae of the dark-sided cutworm were collected from trap plants of tobacco set in a field of rye at Delhi, Ont., in 1969. They were reared individually to pupation to determine the degree of survival and the causes of mortality from the fourth instar to maturity. About 36% pupated and the greatest amount of mortality was caused by insect parasitism, a microsporidial disease, and bacterial infection. Fungus and virus diseases were virtually absent. As adult females are capable of laying a large number of eggs, mortality in eggs and young larvae must reach at least 98% to maintain a stable population. Introduction of virus pathogens to attack larvae might well be expected to result in regulating the population at a lower density.

The responses of adult cabbage maggot [Delia radicum (L.)], turnip maggot [D. floralis (Fallén)], radish maggot [D. planipalpis (Stein)], and seedcorn maggot [D. platura (Meigen)] to sticky traps painted blue, yellow, green, non-UV-reflecting white, or UV-reflecting white, were determined in a field of canola (Brassica rapa cv. Tobin) at the rosette and flowering stages. Traps colored white, blue, or yellow generally caught higher numbers of D. radicum, D. floralis, and D. planipalpis than did traps colored green or UV-reflecting white. Depending on the crop developmental stage and its background color, response to color sometimes differed both within and between the sexes. This was most pronounced for D. floralis, for which blue and white traps were preferred by males at the rosette stage but not die flowering stage, and for which white, but not blue, traps were preferred by females at the rosette siage. White and blue, but not yellow, were the colors preferred by male and female D. platura in our study, with UV-reflecting white also being preferred by males during the flowering stage. It was observed dial catches on white and yellow traps were often significantly different and [hat white versus yellow preferences could be reversed within or between males and females of certain species during the rosette or flowering stages. The data suggest dial the concurrent use of white and yellow sticky traps should be considered when conducting relative abundance surveys of Delia spp. in canola fields.

Drift of aquatic insects was compared at three sites downstream (21, 38, and 107 km) from methoxychlor treatment (0.3 mg. L−1 for 15 min) of the North Saskatchewan River, relative to an upstream untreated site. Species of Diptera (Simuliidae), Ephemeroptera (Baetidae, Heptageniidae, Ephemerellidae, Ametropodidae, Metretopodidae, and Tricorythidae), Plecoptera (Perlodidae and Chloroperlidae), Trichoptera (Hydropsychidae and Hydroptilidae), and Hemiptera (Corixidae) were studied. Drift responses differed depending on species, distance from the injection site, and time after methoxychlor injection. Exposure to methoxychlor initiated catastrophic drift of aquatic insects at all downstream sites. Of 22 species compared before treatment and following methoxychlor injection, post-treatment drift of 17, 21, and 13 species significantly exceeded pre-treatment drift at the km 21, 38, and 107 sites, respectively. Methoxychlor treatment initiated or increased drift of several normally non-drifting species. Similar drift patterns were observed among closely related taxa during the catastrophic phase. For all species studied, comparisons of 24-h drift densities between days preceding and following the catastrophic phase of treatment indicated significant post-treatment drift density increases or decreases at one or more of the downstream sites, but not at the untreated site. Species were classified according to their drift responses to methoxychlor treatment. Factors that may have caused different drift responses among species are discussed.

Agrilus anxius Gory has been reported as breeding in numerous species of birches and poplars. Because species of Agrilus are often poorly characterized morphologically, and usually restrict their feeding to one or to a few closely allied species of plants, it has been suspected that two species were confused. Barter, working in New Brunswick, noted that male specimens reared from, or artracted to, birches and poplars were separable allvays by characters of their genitalia. He found also the differences in biology which described below. Study of material in the Canadian National Collection and the U.S. National Museum shows that the genitalic characters hold in specimens associated with food-plants in other localities. Smith (1949, Nature 164: 237), working with material reared in New Brunswick, found that males and females from birches have 22 chromosomes, and those from poplars only 20. Thus it has been demonstrated that two species, one feeding on birches, the other on poplars, have been confused as Agrilus anxius.

Linear regression analysis was used to estimate the developmental threshold, t0, and thermal constant, K, for all preadult stages of two laboratory colonies of the mosquito Toxorhynchites rutilus septentrionalis (Dyar and Knab). The colonies originated from Newark, Delaware and Lake Charles, Louisiana. The physiological and ecological significance of the within- and the between-population differences in the slopes of the regressions,t0's and K's, are discussed.

Morphometric data were collected on 15 characters in adults of the species of the Pissodes strobi complex (P. nemorensis (Germar), P. schwarzi Hopkins, P. strobi (Peck), and P. terminalis Hopping). Data were examined using stepwise discriminant analysis to determine if all characters contribute significantly to the diagnosis of taxa, and their relative amounts of resolving power were illuminated using canonical variates analysis. Discriminant functions were generated to diagnose species. Separate discriminant functions were generated for each sex for populations from eastern and western North America. Significant sexual dimorphism and variability in body size decrease the utility of morphological characters for diagnosis, but did not prevent the formulation of useful discriminant functions, particularly when selected ratios that control for body size were added.

Tests were performed to determine whether combining two thrips lures, ethyl nicotinate (EN) and ethyl isonicotinate (EI), in the same water trap increased the numbers of New Zealand flower thrips (NZFT), Thrips obscuratus Crawford, and onion thrips, T. tabaci Lindeman (Thysanoptera: Terebrantia: Thripidae), caught in the field relative to traps with a single lure. Traps with both lures (1:1 ratio; mixture or separate adjacent vials) caught 5–9 times more female onion thrips (thelyotokous populations are the most prevalent in New Zealand) than traps with EN only (P<0.001), but in similar numbers to traps with EI only. Traps with both lures caught 2–3 times as many male and female NZFT than traps with EI only, but in similar numbers to traps with EN only. Thus, a combination of the two lures in one trap could be used to detect and monitor flying onion thrips and NZFT simultaneously.