The immature stages of Panzeria ampelus (Walker) are described and illustrated.

Coccinellids are a conspicuous group of aphidophagous predators in maize, Zea mays L., in the Northern Great Plains of the United States. Numerous studies have been conducted on the ecology of coccinellids in maize in North America (Ewert and Chiang 1966a, 1966b; Smith 1971; Foott 1973; Wright and Laing 1980; Corderre and Tourneur 1986; Corderre et al. 1987). However, there have been few long-term surveys of coccinellids in maize. Foott (1973) reported on the abundance of coccinellid species inhabiting maize in eastern Canada over a 4-year period; no surveys of this type have been reported for the Northern Great Plains. We sampled coccinellids in maize fields at three sites in eastern South Dakota for 13 consecutive years to determine the species inhabiting the crop and levels of variation in their abundances among sites and years.

Studies were conducted from 1985 to 1988 in commercial corn fields distributed throughout the main corn growing areas of Manitoba to determine the distribution, phenology, and the level of infestation of the European corn borer, Ostrinia nubilalis (Hübner). Pheromone and blacklight traps were used to monitor the flight activity of European corn borer throughout the flight period. The level of European corn borer infestation was determined by sampling for egg masses, hatched egg masses, plants with egg masses, plants with shot holes, larvae, and stalk breakage. Results indicated that the European corn borer infestation occurred throughout the corn growing areas of Manitoba and that the population has declined from 1985 through 1988. Significant positive correlations existed among the number of egg masses, plants with egg masses, plants with shot holes, larvae per plant, and plants with broken stalks. Peak capture of moths in pheromone traps occurred well after peak oviposition, and 10–14 days after the peak blacklight trap capture. Blacklight trap catch, but not the pheromone trap catch, was positively correlated with egg mass density. Both blacklight and pheromone traps were equally efficient in determining the onset and the duration of European corn borer flight, although for initiating surveys of egg masses and shot hole damage, pheromone traps are recommended. In Manitoba, corn growers apply pesticides well before the recommended damage threshold is reached.

The sunflower stem weevil, Cylindrocopturus adspersus (LeConte), infests wild and cultivated sunflowers in Colorado, Texas, North Dakota, South Dakota, and Minnesota (Schulz 1978; Charlet 1983). It was first observed in Saskatchewan in a sunflower test plot near Carnduff, in August 1984 (unpublished data). Its abundance and distribution in the major Saskatchewan sunflower growing area, in the Carnduff, Estevan, and Weyburn areas, had not previously been studied.

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).

Rangeland grasshoppers commonly are reared through a single generation in the laboratory from eggs collected in the field or produced by field-collected adults. These grasshoppers usually undergo an obligate egg diapause. The only exceptions are nondiapause strains of an economically important grasshopper, Melanoplus sanguinipes (F.) (Pickford and Randell 1969; Henry 1985).

In Ontario several species of polyphagous arthropods consumed nymphs and apterous adults of the green apple aphid, Aphis pomi DeGeer, as determined by serological assays and feeding trials. The most abundant predators on apple tree foliage were the reduviid Acholla multispinosa L., the mirid Campylomma verbasci (Meyer), the coccinellids Coccinella septempunctata L. and Adalia bipunctata L., and coccinellid and chrysopid larvae. An efficacy index developed to assess the effectiveness of foliage-inhabiting predators indicated that those with the greatest potential were Chrysopa larvae and adult C. septempunctata in 1987, and adult C. septempunctata and C. verbasci in 1988. The earwig, Forficula auricularia L., showed potential as a predator of A. pomi in 1989. Of the epigeal arthropods tested, the carabids Amara aenea DeGeer, Bembidion quadrimaculatum oppositum L., and Harpalus aeneus F., and the ants Formica fusca group, Myrmica ameryana Forel, and M. monticola Wheeler were the most active feeders on A. pomi.

Altica subcostata sp.nov. is described and illustrated. This flea beetle feeds on Betula spp. and is recorded from Manitoba, Alberta, and British Columbia.

The attractiveness of the aggregation pheromones produced by males of four species of Ips pine bark beetles was assessed to determine whether competition for a private communication channel among sympatric species or phylogenetic divergence better explains the current pheromonal specificity among the species. In the southeastern United States, Ips calligraphus (Germar), I. grandicollis (Eichhoff), and I. avulsus (LeConte) are broadly sympatric and they represent three different species groups. A member of the I. grandicollis species group, I. confusus (LeConte), is allopatric to the other three and native to the southwestern United States. Only the pair of species from the same species group were pheromonally cross-attractive. Broadly allopatric species from dissimilar species groups were not cross-attractive. Thus, their pheromonal specificity paralleled their taxonomic relationship regardless of geographic overlap and competitive interaction.

A fifth species of the genus Eudigraphis, E. sinensis sp.nov., and a third species of the shinoharai group of the genus Polyxenus, P. hangzhoensis sp.nov., are described, representing the first records of penicillate diplopods from China.

A degree-day model was developed for Alberta populations of Ostrinia nubilalis Hübner. Starting with overwintered fifth-instar larvae, the model calculates the temporal distribution of first- and second-instar larvae which are the stages most vulnerable to chemical suppression. Predictions from three alternative models were compared against field data from southern Alberta. Use of a standard 10°C growth threshold to calculate physiological time scales allowed predictions as accurate as those obtained using either a pooled threshold (11.4°C) calculated specifically from Alberta populations, or a model using two thresholds (12.3°C for fifth-instar larvae to adult and 10.2°C for eggs to second-instar larvae) that incorporated significant differences in growth characteristics observed among life stages. We conclude that standard thresholds are sufficient for degree-day models for northern populations of O. nubilalis. The standard model (t 0 = 10°C) predicts that moth emergence will peak at ca. 145 degree-days after median pupation, and that numbers of eggs, and first- and second-instar larvae should peak at 200, 310, and 450 degree-days, respectively. Model predictions can be used to time sampling effort in support of management decisions.

Trichogramma pretiosum Riley was released in the field for suppression of corn earworm, Heliothis zea (Boddie), egg populations in Nova Scotia in 1985–1987. Trichogramma pretiosum reduced com earworm populations 7.4–53% compared with chemical treatments reductions of 19–100%. Trichogramma pretiosum were not as effective as insecticides, especially when populations of the corn earworm were low (less than five larvae per 1000 ears). Timing of T. pretiosum releases and spray applications were determined by blacklight trap catches and were considered critical for effective control.

In 1983, while sorting Campopleginae in the Canadian National Insect Collection, Biosystematics Research Centre, Ottawa, Ont., I discovered two females of a species of Nemeritis Holmgren. In North America this genus was previously known only from the west (Townes 1970) so it was surprising to see specimens collected in Maine (Sherman Mills, 24.VI–4.VII.1973, G. Heinrich). A survey of the genus showed that these specimens are indistinguishable from the European species N. lativentris Thompson. It is impossible to determine whether or not this is a recently established species as I have been unable to locate more specimens.

The alfalfa leafcutting bee, Megachile rotundata (Fab.), is an important domesticated pollinator of alfalfa grown for seed in Canada. Chalkbrood, a disease caused by the fungus Ascosphaera aggregata Skou, has caused high mortalities in M. rotundata populations in the northwestern United States since 1972. Chalkbrood was found in Manitoba in 1982, Alberta in 1983, and Saskatchewan in 1984 (Richards 1985). Although subsequent surveys have indicated the presence of A. aggregata at high levels in some southern Alberta M. rotundata populations, the disease has been detected only sporadically and at low levels in Saskatchewan populations (Goerzen 1990).

The eastern spruce budworm, Choristoneura fumiferana Clemens, is the most widely distributed and destructive forest insect pest in North America. Although much is known about the ecology, population dynamics, and impact of C. fumiferana on tree growth (Sanders et al. 1985), there is very little information available on the physiology of this forest pest. Physiological studies are crucial to the development of novel strategies for spruce budworm control.