The sweetpotato whitefly, Bemisia tabaci (Gennadius), was accidentally imported into Canada on poinsettia, Euphorbia pulcherrima Willd., cuttings from the United States in 1987 and in 1988. The biology and population dynamics of B. tabaci were reviewed by Butler et al. (1986). It is a worldwide pest of more than 500 plant species in 74 families. Prior to 1986, there was only one report of this insect as a greenhouse pest, on vegetables in Turkey (Lopez-Avila and Cock 1986). Bemisia tabaci was first reported on poinsettia in Florida greenhouses in November 1986 (Price et al. 1987). In 1987, this insect was reported as a pest on field tomatoes in Florida (Schuster and Price 1987).

An improved bioassay using closed glass units was developed for the sex pheromone of the male Queensland fruit fly, Dacus tryoni (Froggatt). Female responsiveness in glass units was quantitated and compared with that in cages, using probing with the ovipositor as the "key response". The median effective dose of pheromone required to elicit a response in 50% of the females (BR50) was much lower in glass units (< 1 male equivalent) than in cages (2.7 male equivalents), and the females also responded more rapidly. As the bioassay is adaptable to a wide variety of laboratory modifications it may be suitable for studying the sex pheromone of other Tephritidae.

A phenology model based on a time–temperature relationship has been developed for the western cherry fruit fly, Rhagoletis indifferens Curran. The model predicts the occurrence of various biological events such as emergence levels, mating, oviposition, larval appearance, parasite activity, and pupation. These events are predicted as a function of summation of thermal units (TU) starting 1 March. For example, emergence begins at 462, oviposition at 541, hatch at 594, and pupation at 795 TU. The model was validated by actual field observations for a period of 3 years (1976–1978). Extended validation of first emergence was obtained from an entirely different cherry growing area, the Hood River Valley. The model could be a useful tool in integrated pest management program on cherries.

The effect of selected constant temperatures (15.6°, 21.1°, 26.7°, 32.2°, 37.8 °C) on oviposition, feeding, and longevity of Liriomyza trifolii (Burgess) was examined in the laboratory with chrysanthemum, Chrysanthemum morifolium Ramat, as a host plant. There was no significant difference in total feeding at 21.1°, 26.7°, and 32.2 °C nor was there significant difference in egg deposition at these temperatures. The ratio egg deposition: feeding was significantly larger at 26.7 °C. Longevity was similar (12–16 days) at all temperatures except 37.8 °C where it was reduced to ca. 3 days. The effect of temperature was more pronounced when feeding and oviposition were analyzed per day. Maximum feeding occurred at 32.2 °C while significantly more oviposition was found at 26.7 °C. An estimate of the threshold temperature for oviposition was 12.2 °C which was higher than that observed experimentally (10 °C). Ninety percent of oviposition occurred with 550°D of adult female life (above base 10 °C).

We analyzed the phylogenetic relationships between eight Aphidius Nees and six Lysaphidus Smith species on the basis of 12 morphological characters by parsimony analysis. The consensus tree does not support the generic status of Lysaphidus. Aphidius iranicus, sp. nov., associated with Titanosiphon bellicosum Nevsky on Artemisia absinthium L. from Iran, is described. The new parasitoid species is described and illustrated by line drawings, and its diagnostic characters are discussed. The taxonomic position of the subgenus Tremblayia Tizado and Núñez-Pérez is also considered. Tremblayia and Lysaphidus are newly classified as synonyms of Aphidius. The following new or revised combinations are proposed: Aphidius adelocarinus Smith, comb. rev., A. ramythirus Smith, comb. rev., A. rosaphidis Smith, comb. rev., A. viaticus (Sedlag), comb. nov., A. arvensis (Starý), comb. nov., and A. erysimi (Starý), comb. nov.

A female Priacma serrata (LeConte) was collected near Procter, B.C., and kept alive for 63 days. It mated and produced 1,463 eggs. Egg and first-instar larva are described briefly.

North American Ips of Group II (Hopping, 196îb) are I. emarginatus (Leconre) and I. knattsi Swaine. They are the only Ips having the third declivital spine emarginate ar the tip. They breed in various species of pine. The distribution of I. emarginatus is from southern British Columbia to California and eastward to Montana. I. knausi is found in Colorado, New Mexico and Arizona. A key to the species is given. I. plastographus (Leconte) is the sole representative of Group III. It is the only four-spined Ips with the sutures of the autennal club strongly angled at the middle. I. plastographus breeds in species of pine. It occurs from southern British Columbia southward in the western United States and through Mexico into Guatemala. Hosts and more detailed distributions are given for species in Groups IT and III.

Fertility of Achaearanea tepidariorum (C. L. Koch) that were fed mosquitoes chemosterilized by pupal exposure to thiotepa was significantly reduced. Mortality was excessive for spiders fed mosquitoes treated topically with thiotepa. Maximal weekly dosages, estimated by residue analysis, were 12 and 21 ng/male and female respectively for spiders fed mosquitoes treated as pupae and over 3 times greater for spiders fed mosquitoes treated topically as adults. The susceptibility of this predator to small chronic dosages of chemosterilant suggests that mass releases of chemosterilized insects are potentially hazardous to food chain components.

Timema douglasi sp.nov. is described from southwestern Oregon and northern California, USA. It is the third parthenogenetic species in the genus and is a specialist feeder on old-growth Douglas fir, occasionally causing serious defoliation. Timema knulli Strohecker is synonymized with Timema californicum Scudder.

To test the hypothesis that bark beetles and some associated insect species are attracted to ponderosa pines infected by Ceratocystis wageneri, insect visitations on 11 severely diseased, 9 moderately diseased, and 10 apparently healthy trees were monitored from 1 August to 15 October 1972. Larger numbers of Dendroctonus brevicomis, D. ponderosae, Temnochila chlorodia, and buprestids were captured on diseased trees uninfested by bark beetles than on apparently healthy ones, thus possibly indicating attraction to diseased trees. There was strong evidence that D. valens and Spondylis upiformis were attracted more frequently to wounds on diseased than on healthy trees. Arrival patterns of beetles were recorded for trees that became infested during the study. Predators became abundant on traps as bark beetle catches increased.

Two of the five Nearctic species of the subgenus Bombus Latr. occur in southern Alberta. Both are bush-inhabiting species. One, B. occidentalis Greene, is confined to the treed areas of southern Alberta whereas the other, B. terricola Kby., although found throughout the treed areas of the province, is much more prevalent in the central and northern regions. Both species emerge and establish nests early, and nest almost exclusively in hives reached by means of downward-sloping tunnels. Many queens of B. occidentalis camouflage or restrict tunnel entrances by dragging grass in and around them. B. occidentalis produced 8.6±0.5 eggs in the first broods, 4.2±1.1 eggs per cell in the second and third broods, and 6.6±0.9 eggs per cell in the fourth brood. This species is intermediate in rank among southern Alberta species of Bombus Latr. in its ability to produce wax. As are other early emerging species, it is heavily depredated by Psithyrus spp.

Ovarian development and egg production in the larch sawfly, Pristiphora erichsonii (Hartig), were studied in the development of a method for measuring reproductive capacity for population studies. Most of the oöcytes are mature at the time of adult emergence but some mature in the following few days. Quantitative differences in foliage consumption during the larval stages have an appreciable effect on egg production but normal environmental temperature differences and exposure to flooding during the spring development period influence ovarian development only to a limited extent.

Reproductive capacity can be determined by oöcyte counts of dissected adults of uniform age. The sample size necessary for estimates of various degrees of precision was calculated.

Several size measurements have a significant correlation with the numbers of oöcytes produced. The regression of numbers of oöcytes on adult weight is of limited usefulness in the estimation of reproductive capacity. This is largely due to the individual variability in the extent to which fat body tissue is utilized in ovarian development particularly in the case of the larger adults.

The toxic effects of a number of orchard spray chemicals on predators and parasites were given in an earlier paper (MacPhee and Sanford, 1951), which presented results obtained before 1953 and gave a list of biotic control agents, their hosts, and periods of activity. It also gave a review of the literature, showing in tabular form the effects of orchard pesticides on beneficial species.

The effects of Bacillus thuringiensis var. israelensis de Barjac (B.t.i.) on the feeding habits of two black fly predators, Nigronia serricornis (Say) and Acroneuria lycorias (Newman), and a detritivore, Prostoia completa (Walker), were examined. We assessed whether B.t.i.-killed and hot water-killed black fly larvae were less or more desirable to these consumers than live larvae. Nigronia larvae showed no significant differences in predation on larvae within the three categories. Acroneuria nymphs consumed more live than dead prey. Experiments with the detritivore, Prostoia, showed that they preferred dead black fly larvae to live ones. Bacillus thuringiensis var. israelensis treatment may have little direct effect on nontarget organisms, but these studies indicate that there still may be consequences for predators and detritivores when a viable population of larval black flies is transformed into dead organic matter.

Comparison of type material and series of Ips cribricollis (Eich.) and I. grandicollis (Eich.) showed that the species are readily separated by external morphology, the pars stridens of the females, and, especially, the genitalia of the males. Earlier work showed that representatives of the two species were not able to interbreed and that their chromosomes were different. These data and the discovery of the two species at the same locality in Central America are compelling reasons for recognition of these entities as separate species.

Vertical gradients in biotic and abiotic factors may create small-scale spatial variation in arthropod communities, a phenomenon that continues to be understudied. We investigated heterogeneity in the vertical distribution of spider and beetle assemblages in the canopy of sugar maples (Acer saccharum Marshall) (Aceraceae) in a deciduous forest in eastern Canada. Comparisons across four strata (understorey [UN] through upper canopy [UC] crown) documented variation in density, diversity, and species composition. Density of all common families decreased significantly with height and overall species richness of both spiders and beetles was highest in the UN and lowest in the UC crown. We observed greater spatial variation in spider assemblages compared with beetle assemblages and documented differences in spider guild structure: web-spinning spiders were most common in the UN and jumping spiders dominated the canopy. Our results suggest that arthropod assemblages are not homogeneous with respect to vertical space and that heterogeneity exists even at the scale of several metres.

The reliability of three methods for sampling aphidophagous coccinellids and syrphids in a winter wheat field was compared.

In the first method, an observer recorded predators seen during 2 min per 25-m2 sub-plot. In the second, two observers worked successively through each plot, scanning the full height of wheat plants and collecting predators. This method enables calculation of predator density using De Lury’s technique. The third method consisted of collecting wheat plants from each sub-plot for examination in the laboratory.

The first method may be used for appraising populations of adult coccinellids on a large scale. The detailed searching method is appropriate for studies of the population dynamics of adult and fourth-instar coccinellids. The plant sampling method is the most accurate for assesssing densities of syrphid larvae and pupae.

In 2010–2011, we studied the European oak borer (EOB), Agrilus sulcicollis Lacordaire (Coleoptera: Buprestidae), in Michigan, United States of America, and made comparisons with the native twolined chestnut borer (TLCB), Agrilus bilineatus (Weber). EOB adult flight began and peaked before TLCB. More EOB females were captured on purple and white compared with yellow and green sticky traps. More TLCB females were captured on purple, followed by yellow, green, and white, respectively. Male EOB and TLCB did not show a significant colour preference. EOB completed development primarily from areas of artificially girdled trees where the phloem had died soon after trees were girdled, while TLCB usually developed in areas of girdled trees that had some live phloem present. Both EOB and TLCB successfully attacked and emerged from girdled Quercus alba Linnaeus, Quercus robur Linnaeus, and Quercus rubra Linnaeus (Fagaceae) trees. No live EOB or TLCB were found in two ungirdled and apparently healthy Q. robur trees that were dissected. EOB attacked and emerged from Q. alba, Q. robur, Q. rubra, and Quercus velutina Lamarck trap logs. Differences in the pronotal groove and terminal processes can be used to distinguish EOB from TLCB larvae. Five species of parasitoids were reared from EOB and four from TLCB.

An extensive survey of chewing lice from rock pigeon, Columba livia Gmelin, and mourning dove, Zenaida macroura (L.), carried out from 1994 to 2000 and from 2003 to 2006 in Manitoba, Canada, produced the following new records: Colocerastovornikae Tendeiro for North America; Columbicola macrourae (Wilson), Hohorstiellalata (Piaget), H. paladinella Hill and Tuff, and Physconelloides zenaidurae (McGregor) for Canada; and Bonomiella columbae Emerson, Campanulotes compar (Burmeister), Columbicola baculoides (Paine), and C. columbae (L.) for Manitoba. We collected 25 418 lice of four species (C. compar, C. columbae, H. lata, and C. tovornikae) from 322 rock pigeons. The overall prevalence of infestation was 78.9%, 52.5%, and 23.3% for C. compar, C. columbae, and H. lata, respectively. Coloceras tovornikae was not discovered until 2003, after which its prevalence was 39.9% on 114 pigeons. We collected 1116 lice of five species (P. zenaidurae, C. baculoides, C. macrourae, H. paladinella, and B. columbae) from 117 mourning doves. Physconelloides zenaidurae was encountered most often (prevalence was 36.7%), while the prevalence of the other four species was 26.3%, 18.4%, 3.5%, and 2.6%, respectively.