Aphis martinezi sp.nov. and Aphis paravanoi sp.nov. from Argentina and Aphis roberti sp.nov. from Argentina and Chile are described. These new species live on the South American plants of the genus Mulinum Persoon, 1805, as do Aphis mulini Hille Ris Lambers and Aphis mulinicola Hille Ris Lambers, which were previously described from Argentina. A key for the apterous viviparous females of these five species is given.

The subfamily Agriopocorinae Miller 1954 is reduced to tribal rank, with the new status Agriopocorini Miller. The tribe Agriopocorini is redefined, and three new genera (Agriopocostella gen.nov., Agriopocoscelis gen.nov., and Agriopocodemus gen.nov.) and four new species (Agriopocoris dollingi sp.nov., Agriopocostella rugulosa sp.nov., Agriopocoscelis elongatus sp.nov., and Agriopocodemus inexspectatus sp.nov.) are described and illustrated; Agriopocoris dimorphus Stys is synonymized under Agriopocoris froggatti Miller, and Agriopocoris macilentus Miller under Agriopocoris porcellus Miller. New distributional data and trophic preferences for plants of the family Leguminosae are included. Dorsal habitus, antennal segments, head, pronotum, male genital capsule, and parameres are illustrated, and a checklist and key to the known genera and species are provided.

Oogenesis and associated ovarian development were studied from the onset of adult eclosion to oviposition in the European earwig, Forficula auricularia L., by examining histological sections of ovarioles and whole mounts of ovaries. Each pair of ovaries contains a mean of 85.4 ovarioles. Chronologically, oogenesis has been divided into four phases, adult emergence, previtellogenesis, vitellogenesis, and choriogenesis, each described here in detail. The mean size of the basal follicle increases from 15 μm at time of adult emergence to 0.9 mm at time of choriogenesis, and the oocyte to trophocyte ratio increases from 1.0 to 4, with a minimum of 0.5 at the onset of previtellogenesis. The oocyte to trophocyte ratio of 0.7 marks the onset of vitellogenesis, which lasts about three times (60 days) as long as previtellogenesis. The extended vitellogenesis is still under way when females bury themselves in the ground, in October, in the Montréal area.

Growth, number of fusions, and polyploidy of ovarian trophocytes were studied in the European earwig, Forficula auricularia L., from the imaginal moult to oviposition, by examining sections of ovarioles and whole mounts of ovaries. During a reproductive cycle, the nucleus of the basal trophocyte enlarges its mean diameter from 5 to 170 ± 33 μm, successively absorbing the trophocyte nuclei of both adjacent follicles and undergoing seven endoreplications. The nucleus thus increased its DNA content 192 times, which is 66.7% more than in the artioploid type of polyploidy. However, vitellogenesis lasted about three times longer than previtellogenesis. This type of polyploidy accelerates oogenesis, allows an earlier oviposition, and may constitute an adaptation specific for the Montréal population of earwigs.

Results of a 2-year survey in Alberta, Canada, identified a parasitoid fauna of filth flies distinct from that generally reported for cattle confinements in the United States. Twenty-two feedlots were surveyed using freeze-killed sentinel house fly pupae. Parasitism averaged 0.25%. Ten species of hymenopterous parasitoids were recovered. As a percentage of the total number of pupae parasitized, these species were Muscidifurax raptor Girault & Saunders (37.4%), Trichomalopsis sarcophagae Gahan (23.9%), Urolepis rufipes (Ashmead) (18.5%), Muscidifurax zaraptor Kogan & Legner (6.9%), Nasonia vitripennis Walker (6.5%), Trichomalopsis sp. (3.7%) (Pteromalidae), Phygadeuon sp. (2.9%) (Ichneumonidae), Dibrachys cavus (Walker) (0.1%) (Pteromalidae), Synacra sp. (0.1%) (Diapriidae), and an unidentified Braconidae (0.1%). No differences were detected among natural regions of the province. Three categories of seasonal activity are identified which expand on previous groupings of species by their geographic distributions. The abundance of T. sarcophagae and rarity of species of Spalangia Latreille, 1805 are in marked contrast to results of surveys conducted in the United States. This difference suggests that species used to manage populations of pestiferous flies associated with livestock in the United States could be inappropriate for use in Canada.

Colonies of the honey bee, Apis mellifera Linnaeus, infested with the parasitic mites Acarapis woodi (Rennie) (Acari: Tarsonemidae) or Varroa jacobsoni Oudemans (Acari: Varroidae) require acaricidal treatment to control infestations that could affect colony growth and honey production. We investigated the effects of three acaricides, fluvalinate (formulated as Apistan®), formic acid, and menthol, on honey bee colony population growth, foraging activity, adult worker longevity, and honey production. Effects of in-hive treatments of Apistan® and formic acid were measured by examining colony weight gain, brood survival, sealed-brood area, emerged-bee weight, number of returning foragers, pollen-load weight, and worker longevity. These characteristics were not different between fluvalinate-treated colonies, formic-acid-treated colonies, and control colonies. Adult bee population, brood survival, number of returning foragers, and honey production did not vary among menthol-treated colonies, formic-acid-treated colonies, and control colonies. Sealed-brood area was lower in formic-acid-treated colonies than control colonies, but not different from menthol-treated colonies. Although not statistically significant, formic-acid-treated colonies experienced lower honey production than both menthol-treated and control colonies. Numbers of workers attending the queen in the retinue and queen behaviour patterns were not different after colonies were treated with formic acid.

Following a 3-year period of high populations of the little spruce sawfly, Pristiphora abietina Christ, a monophagous species infesting Norway spruce, Picea abies Karst., we compared variations in foliar nutrients (nitrogen, water, soluble carbohydrates, starch) and potential defensive compounds (fiber, quinic and shikimic acids, tannins) of trees that had been subjected to high or very low levels of defoliation. During the time of needle expansion a substantial decline in leaf quality occurred: nitrogen, water, and carbohydrate levels decreased, whereas fiber and starch concentrations increased. Allelochemicals such as tannins and organic acids, however, peaked at bud break and then rapidly declined. More heavily attacked trees had higher nitrogen, water, and fiber contents but lower starch and organic acid concentrations than lightly attacked trees. The needle tannin content was significantly lower in heavily attacked trees throughout the period of larval feeding. Needle tannin levels and the nitrogen to tannin ratios seem to be the most probable traits to distinguish sawfly-resistant from sawfly-susceptible Norway spruce trees.

The wheat midge Sitodiplosis mosellana (Géhin) occurred in all wheat-growing areas of Manitoba during 1993–1997, with 95% of spring wheat fields having some seeds infested by larvae. The level of infestation varied, but each year in excess of 20% of seeds were infested in some fields. Infestation levels in adjacent fields were more similar than in fields separated by a few kilometres. Within fields, the infestation was similar at the edge and near the centre. Wheat midge larvae also overwintered in, and adults emerged from, fields in all wheat-growing areas of Manitoba. Adults emerged from the end of June to the end of July most years, and the peak period for adult flight was mid-July, about 1 month later than in parts of Europe where winter wheat predominates. The timing of the emergence was similar from place to place and year to year. Females constituted 95% of insects caught in a flight trap. The first 10% and 50% of the flight occurred on 9 and 16 July, respectively, and the timing of the flight was not related to growing degree-days. In early August, mature larvae began dropping from wheat heads. The timing of infestation of spring wheat was variable among years because of differences in timing between midge flights and the susceptible heading stage of the crop. Nevertheless, the wheat midge flight usually coincided with the susceptible stage of the spring wheat crop.

Fourteen species of parasitoids (13 hymenopterans, 1 dipteran) were reared from larvae or pupae of the obliquebanded leafroller, Choristoneura rosaceana (Harris), collected from commercial raspberry fields in the Fraser Valley, British Columbia, Canada, over 3 years. Levels of parasitism ranged from 5 to 15%. Among these 14 species, five represent new host records. A polyembryonic wasp, Macrocentrus nigridorsis Viereck (Hymenoptera: Braconidae), was the most abundant parasitoid. External feeding on the final host instar is obligatory for M. nigridorsis to complete development. On average, each parasitized host larva produced about 36 M. nigridorsis, in either unisexual or mixed-gender groups. Overall male to female sex ratio was 1:4. Head capsules of mature parasitized host larvae were significantly larger than those of unparasitized ones, suggesting that C. rosaceana larvae parasitized by M. nigridorsis might have an extra larval stage.

At Alexandra Fiord, Ellesmere Island, the diving beetles Hydroporus morio Aubé and Hydroporus polaris Fall occur in a series of shallow ponds. Detailed habitat measurements of a temporary and a permanent pond revealed a more complex and extensive organic substrate and vegetation community, longer developmental time, and greater thermal budget in the permanent pond. Hydroporus polaris was most abundant in the temporary pond, but occurred in both; this species oviposited in the absence of macrophytic vegetation, completed larval development quickly, and pupated in the drying pond substrate, and adults dispersed in fall to moister overwintering sites. Hydroporus morio was restricted to the single permanent pond; this species took longer to complete larval development, pupated in wet moss, and overwintered as adults encased in ice on the vertical pond edge. We hypothesize that H. morio is excluded from temporary ponds in the arctic by its requirement for a relatively long development time. Alternatively, H. morio may require sheltered overwintering sites that temporary ponds do not offer.

New Brunswick experienced its first recorded outbreak of hemlock looper, Lambdina fiscellaria fiscellaria (Guenée) (Lepidoptera: Geometridae), in 1989 (Magasi1990). Since 1993, populations have remained at endemic levels. From 1989 to 1994, when annual egg surveys were conducted (from October to April) on balsam fir, Abies balsamea (Linnaeus) Miller (Pinaceae) to forecast the next years' population for planning foliage protection programs, the egg parasitoids Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae) (Hartling et al. 1991) and Telenomus near alsophilae Viereck (Hymenoptera: Scelionidae) were frequently reared from overwintering looper eggs. We believe two factors can cause an underestimation of egg parasitism rates by Telenomus near alsophilae: (i) eggs parasitized by Telenomus near alsophilae can be difficult to identify, and need to be reared to detect the black shading on the chorion which ranges from a mere dark spot to some gradation of black over the entire surface; and (ii) additional parasitism by this parasitoid might occur in spring. Our estimates of egg parasitism rates were as high as 23% (n = 93) from spring-collected looper eggs incorrectly classified as viable until incubated in the laboratory. We describe part of an experiment that confirms spring parasitism by this species, and illustrate the implications to operational looper control operations.