Resorption of terminal oocytes was investigated in 3 species of grasshoppers, Melanoplus femurrubrum femurrubrum (DeGeer), M. scudderi (Uhler), and Hippiscus ocelote (Saussure). Significant differences in percentage resorption were found between species. Anterior ovarioles resorbed terminal oocytes more frequently than ovarioles in the middle and posterior regions of the ovaries. Resorption of terminal oocytes due to differences in relative ovariole age does not appear to be a factor in percentage resorption based on the lengths of developing terminal oocytes. There was no difference in percentage resorption of terminal oocytes between ovaries.

In a recent monograph of the plant bugs of the prairie provinces (Kelton 1980), I stated that the subfamily Cylapinae did not occur in the prairie provinces. However, collections in 1982 and 1983 in Manitoba and Alberta produced specimens of Fulvius imbecilis (Say). This is the first record of this species in Canada. Additional records for Canada are given for F. slateri Wheeler, imbecilis is illustrated, and a key to separate them is provided.

Predispersal seed predation of Cirsium arvense (L.) Scop. (Asteraceae) by Orellia ruficauda (Fabr.) (Diptera: Tephritidae) occurs in about 20–85% of the seed heads and the proportion of damaged seeds per attacked head averages 20–80% depending on geographical location and sampling date. Microscopic studies of damaged seeds were performed. Although the impact of this seed predator is not severe, it may be an important factor in the population regulation of the weed.

Data from 87 trees within 21 natural infestations were used to estimate the population size of the southern pine beetle (Dendroctonus flontalis Zimmermann) under collapsing high-level conditions in North Carolina. Spots of K trees (1<K<12) were created by random selection without replacement from the initial pool. Samples of m trees (1<m<K) were then chosen from each simulated spot according to random and selective plans. These samples over m trees were then extrapolated to the full K tree spot by 1 of 3 scaling factors: percentage of trees sampled, percentage of diameter sampled, or percentage of phloem area sampled. In this manner the total numbers of parent adults, brood, and brood adults were estimated for each artificial spot. Proportional errors, defined as (observed value – expected value)/(observed value), were computed over 10 000 independent trials for a variety of sample sizes, spot sizes, and scaling factors. The precision of these errors, after a bias correction was applied, was used to compare the different schemes. Random-diameter and largest-diameter schemes were judged best because of their good precisions and ease of application. However, when these results were applied to the 21 natural infestations, the confidence intervals were found to be too narrow to include the expected number of estimates. A discussion of this shortcoming is discussed in relation to spot dynamics and its effect on the application of this sampling technique.

Detailed generic descriptions are given for the adult male and female, larva, and pupa of Xylotopus Oliver and for the adult male of Irisobrillia n. gen. Two new species, Xylotopus burmanensis and Irisobrillia longicosta, are described. A key is presented to separate adult males of Xylotopus and Irisobrillia from allied genera, Brillia Kieffer, Eurycnemus Wulp, and Euryhapsis Oliver.

A sequential sampling system for early-instar Douglas-fir tussock moth larvae based on beating 3 lower branches from each of a number of trees is described. The relationship between lower- and mid-crown insect densities is given. The number of samples required to assess moderate insect densities using a fixed level of precision and at low insect densities using a critical density level is presented. The system is designed to be used during the early stages of an outbreak in stands not previously defoliated.

The impact of predation by Calosoma sycophanta L. on an increasing prey population was assessed by recapturing marked adult beetles, periodically observing tagged gypsy moth pupae, and examining gypsy moth pupal remains in different microhabitats. Adult beetles dispersed in random directions but many tended to remain near the trap at which they were originally caught, suggesting a low dispersal potential. About 75% of the adult beetles present in the plot on one day were still present the next day. Capture–recapture estimates suggested that there were at most about 250 male beetles and half as many females/ha in the plot. Calosoma larvae destroyed 70% of tagged gypsy moth pupae under burlap bands on tree trunks near ground level, which was much more than any other mortality factor. Although this percentage was the same when mortality was assessed by looking at pupal remains within 5 m of the ground on tree trunks, pupae higher in trees and on leaves were not attacked as frequently. On average, about 40% of the pupae present in the entire study area were destroyed by Calosoma larvae. Each female beetle in the site would have had to produce about 30 progeny to have this effect. These data suggest that a relatively low number of adult beetles can have a substantial impact on gypsy moth populations.

The Cypress Hills consist of a hilly elongate plateau straddling the Alberta–Saskatchewan border. They are mostly covered in a foothills-type vegetation but are surrounded by short-grass prairie and lie about 250 km east of the Rocky Mountain foothills. The upper 95 m remained unglaciated as a nunatak during the Wisconsinan glaciation. Dragonflies were collected at various times during May–August in 1982–1984 at 24 localities in Cypress Hills Provincial Park, Alberta. Thirty-one species were obtained, 3 of which (Aeshna multicolor, Gomphus graslinellus, and Libellula pulchella) are new records for Alberta. The dragonfly fauna of the Cypress Hills consists of species with the following Canadian distributions: 22 transcontinental (13 boreal, 7 southern, and 2 widespread), 4 southwestern, 2 western boreal–northwestern, 2 cordilleran, and 1 primarily prairie. An analysis of this fauna indicates that, following northward retreat of the glaciers, 22% of the present species came from cordilleran regions and 42% were derived from the boreal fauna. This corroborates the boreo–montane forest connection that is considered to have extended along the retreating ice front before the climate became too warm and resulted in the forest being replaced by grassland.

The biology of Telenomus chloropus Thomson was studied on eggs of Nezara viridula (L.) which had been reared on the stink bug resistant soybean, Glycine max (L.) Merrill, genotype PI 171444 and the susceptible cultivar Davis. Time of development of T. chtoropus from egg to adult emergence was not significantly different in eggs oviposited by N. viridula reared on either Davis or PI 171444. However, successful emergence of T. chloropus from host eggs was significantly lower for parasitoids that developed in eggs from N. viridula reared on PI 171444. Longevity of adult T. chloropus was not significantly different between females that were allowed or denied oviposition regardless of the genotype fed the host. Total fecundity of T. chloropus reared from eggs of N. viridula fed PI 171444 was one-half that of parasitoids from the Davis treatment. Although ovipositional patterns over the lifetime of parasitoids from the 2 treatments were similar, the mean number of progeny produced per day was significantly greater in the Davis treatment. Also, the ovipositional period of parasitoids from the PI 171444 treatment was shorter than for parasitoids from the Davis treatment.

The alfalfa leafcutter bee, Megachile rotundata (F.), is the primary pollinator of commercially grown seed alfalfa in Canada. Chalkbrood is a fungal disease, caused by a complex of Ascosphaerales species (Skou and King 1984) that infect the larvae of many species of bees. One species, Ascosphaera aggregata Skou (Skou 1975), is a severe problem in leafcutter bees in the United States and in some cases has caused losses of more than 65% (Stephen et al. 1981). Mode of dispersal, infestation of bee larvae, sporulation, and associated symptomatology of this pathogen have been described (Vandenberg et al. 1980; Vandenberg and Stephen 1982; McManus and Youssef 1984).

Demographic analysis of a species population can be useful in gaining insight into its dynamics in a particular environment. The calculated intrinsic rate of increase of a population may be valuable in predicting population performance. As a single, discrete value, it serves as a quantitative measure, or ecological index, of the response of a species to a set of environmental conditions (Birch 1948; Messenger 1964).

Seedworms of the Cydia piperana complex are major cone pests of ponderosa pine, Pinus ponderosa Douglas ex-Lawson, and Jeffrey pine, P. jeffreyi Greville and Balfour, in western North America (Keen 1958; Hedlin 1967). An effective synthetic attractant could be useful in a trapping technique for predicting damage to seed crops.

Male moths of a biotype in this complex were lured to traps baited with (E)-9- and (Z)-9-dodecenyl acetates during tests to.refine optimum blends of these synthetic chemicals for Rhyacionia and Eucosma shoot moths, and we report the serendipitous findings here.

Secondary metabolites from plants capable of photosensitizing insects include furanocoumarins, furanoquinone alkaloids, beta-carboline alkaloids, polyacetylenes and their thiophene derivatives, and extended quinones (Arnason et al. 1983; Towers 1984). These compounds may have direct lethal effects, retard larval development, or be ovicidal (Kagan and Chan 1983). A remarkable property of these secondary metabolites is their greatly enhanced activity in the presence of sunlight or artificial sources of radiation.

A search is being conducted to determine the indigenous parasites and predators of the alfalfa weevil, Hypera postica (Gyll.), in Alberta (Schaber 1981). A clearer understanding of the biology of the predator Odynerus dilectus Saussure will augment control of the alfalfa weevil in an integrated pest management program.

Odynerus dilectus has been recorded in the United States (Bohart et al. 1982) and in Alberta, Canada (Strickland 1947). In California, Linsley and Michener (1942) reported that females stocked their nests with small caterpillars, but Bohart et al. (1982) reported that in Utah females of O. dilectus provisioned their nests with larvae of the alfalfa weevil. This paper summarizes data about the nesting and prey-provisioning behavior of O. dilectus in southern Alberta.

In Canada, 78 of the most important weed species are introductions from Eurasia (Frankton and Mulligan 1970). Classical biological control aims to reduce the density of alien weeds below the economic threshold through introduction of specific herbivores from the native distribution area (Peschken 1979). During extended field surveys in central and southeastern Europe, the Commonwealth Institute of Biological Control established the root-mining tortricid Agapeta zoegana Haw. as a promising control agent for Centaurea diffusa Lam. and C. maculosa Lam., 2 important ranch weeds in southwestern Canada (Harris and Myers 1984) and the northwestern United States (Maddox 1982). Due to the limited host range and suitable climatic conditions this moth was chosen for introduction into North America (Müller et al. 1982; Müller 1984). We wish to report an attractant that may be used to monitor the establishment of this beneficial species in its new habitat.