Fourteen reciprocal crosses between 11 populations (demes) of troglobitic (obligately cavernicolous) Ptomaphagus beetles were made. Numbers of F1 and F2 larvae and adults are reported. Markedly lower fecundity (but not fertility), viability, and longevity in the hybrids between morphologically distinct populations from Alabama caves indicate substantial reproductive isolation. This and distributional data suggest that the morphologically distinguishable populations are full species.

Barrier-pitfall traps and tree bands were used to sample adult carabid beetles in five forest stands of different tree species composition and spruce budworm infestation levels. Twenty genera and 37 species were collected over the 2-year period. Adult carabid populations were highest in the red spruce stand while carabid species diversity was greater in hardwood and fir stands having the most tree species diversity. Potential adult carabid predators of spruce budworm were identified using 5 criteria: number of individuals, habitat preferences, seasonal abundance, size, and food. We conclude that adults of Pterostichus pensylvanicus (Lec.) had the highest potential as predators of spruce budworm followed by Platynus decentis Say, Calosoma frigidum Kby., Pterostichus tristis (Dej.), Cymindis cribricollis Dej., Pterostichus rostratus (Newm.), Calathus ingratus Dej., and Pterostichus adoxus (Say).

Fourteen new records of introduced leafhoppers are added to the 157 leafhoppers previously recorded as occurring in both the Old and New worlds. Of these, 62 were erroneously recorded previously although 12 of the European species subsequently have been found in North America. Two North American species have been introduced into Europe, and one European species has been found in South America; North America has received 61 species from Europe, 3 from Asia, and 1 from Africa. One pan-tropical species is probably a recent introduction into the Caribbean from the Old World. There are 30 transboreal leafhoppers, 5 transarctic species inhabiting the tundra and alpine meadows, and 9 inhabiting temperate regions of both Eurasia and North America.

The Aster leafhopper (Macrosteles quadrilineatus Forbes) is removed from synonymy with the transboreal sedge-feeding M. fascifrons (Stål) and 25 other confused species are distinguished in the genera Aphrodes, Euscelis, Evacanthus, Limotettix, Macrosteles, and Typhlocyba. These include 11 new species: Evacanthus bellaustralis, E. chlamidatus, E. grandipes, E. lacunar, E. nigramericanus, E. ustanucha, Macrosteles lagus, M. severini, M. tesselatus, M. vilbastei, and Typhlocyba frigida, all from North America, Balclutha punctata confluens Rey and Limotettix striola ferganensis Dubovsky are elevated to species status. One new generic synonymy, 23 new specific synonymies, and 3 new combinations are created.

Scolytus multistriatus female adults demonstrated a distinct preference for English and Siberian elm over Chinese elm in attacking bolts and establishing egg galleries. Density of attacks appeared related to bark roughness of the exposed bolt. A ranking of elm species suitability for S. multistriatus is thus possible. Some of the females forced to attack Chinese elm died after making nuptial chambers but before establishing egg galleries. Egg production by females was unaffected by attack densities observed, elm species, or the place where the trial was conducted. In the laboratory, survival from egg to adult was lower in Chinese elm than in English or Siberian elm. Ability of the larvae to mine outer bark at high densities is believed to be a response to intraspecific competition and probably enhances survival. The first estimates of subcortical population parameters are presented for this species in North America. Adaptive value of variations in relationships between the beetle and various elm species is discussed.

Male and female adults of Cowichania interstitialis n. gen., n. sp. are described, and Cowichaniinae n. subfam. is proposed for members of this genus and species. Adults of the new species are autapomorphic among Hydryphantidae in having an entire, uniformly sclerotized dorsal shield, the dorsoglandularia displaced laterally, the genital field located well posteriorly on the idiosoma, and unique sclerotized plates surrounding the coxal plates laterally and posteriorly, and are unusual in having slightly stalked genital acetabula and sexually dimorphic chaetotaxy on the tibiae of the pedipalps. Provisional remarks on phylogeny and higher classification of Hydryphantidae are also presented.

Larvae, and male and female adults, of Paramideopsis susanae n. gen., n. sp. are described. The genus Paramideopsis is proposed and diagnosed based primarily upon the autapomorphic presence of 6 pairs of genital acetabula on plates flanking the gonopore in adults. Possible relationships between P. susanae and other Mideopsidae are discussed.

Evidence for secondary attraction in the western balsam bark beetle, Dryocoetes confusus Swaine, was obtained in laboratory bioassays and field experiments. Both sexes showed positive responses to volatiles of the host tree, Abies lasiocarpa (Hook.) Nutt., indicating that primary attraction is probably important in host selection by this species. Male beetles initiated attack and within 6 h produced an aggregation pheromone(s), which was present in frass and in pentane extracts of the abdomens of males excised from logs. Both sexes responded to the pheromone. Abdominal extract of unmated males which had bored into host bark for 14 days was still attractive. Pheromone production was induced by exposing males to host resin volatiles. Mating had no effect on male attractiveness, but induced females to produce an antiaggregation pheromone which, in laboratory bioassays, at least partially inhibited response to male attractant. The attractive volatiles from male-infested logs were successfully captured on Porapak Q®. The development of laboratory bioassay and pheromone extraction techniques indicates that a pheromone isolation program is feasible.

Blethisa inexspectata is described as new from one male specimen from Alaska; it is the sister species of B. julii LeConte. The phylogeny and biogeography of Blethisa Bonelli is discussed, and a key to all known species of Blethisa is given. Blethisa kaszabi Jedlička 1967 is placed in synonymy with B. tuberculata Motschulsky 1846.

Among territorial syrphids, males of Eumerus tuberculatus (Rond.) are less aggressive than Merodon equestris (Fab.) and Eristalis tenax (L.) males. This difference in aggressiveness persists even when territorial pressures increase with increasing numbers of conspecifics.

Males of each species recognized conspecific females mainly by a combination of visual and behavioural cues. A territorial male might approach any intruder, but would only attempt to mate if, like the appropriate female, the intruder did not respond to the male's approach. Differences in behavioural patterns may be due to different mating strategies.

Some time ago I published data on orthopteroid insects from northern Canada and Alaska (Vickery 1967, 1969). Two species and one subspecies were described as new. Two of these taxa occur only in the Yukon and Northwest Territories.

Since that time additional information has become available. During 1982 two lots of northern orthopteroid insects were received for identification. These were sent from the Spencer Museum, University of British Columbia and from Biosystematics Research Institute, Canada Agriculture, Ottawa. These are abbreviated in the following list as UBC and CNC, respectively. The UBC specimens were collected by S. G. Cannings, R. J. Cannings, C. S. Guppy, B. Gill, and G. G. E. Scudder mainly in 1980 and 1981. The CNC specimens were collected in 1981 by C. D. Dondale.

The northern corn rootworm, Diabrotica longicornis (Say), was first reported by Guibord (1976) in QuCbec corn fields, and has since been studied intensively as a potential pest of corn. Detailed field investigations of the bionomics were initiated at h4acdonald Campus in 1979, and laboratory research such as physiology and toxicology required the development of techniques for mass rearing of the insects.

Vol. 114, 1982

p. 1102, Table I, column 1, 2nd last entry, forZ7-12:OH + E9-14:Ac read Z7-12:OH + Z9-14:Ac