The development of gypsy moth larvae was monitored in the laboratory on the foliage of 39 species belonging to 18 genera in the Araucaraceae, Cupressaceae, Ginkgoaceae, Pinaceae, Taxaceae, and Taxodiaceae. Larval survival through successive molts, time of larval development, live female pupal weights, and adult female production of ova were measured as indicators of host plant suitability for the gypsy moth. The criteria for distinguishing the most suitable hosts were as follows: (1) greater than 80% survival of first-instar larvae, (2) development to pupation in less than 41 days, (3) female pupal weights over 1099 mg, and (4) the production of more than 350 ova. The most suitable species were in the Pinaceae, in particular, Cedrus deodara (Roxb. ex Lamb.) G. Don, Larix decidua Mill., and Picea pungens Engelm. The least suitable species were in the Cupressaceae, Ginkgoaceae, and Taxaceae. First-, second-, and third-instar larvae often differed in their ability to survive on new foliage compared with foliage from the previous year. Overall, first-instar larvae successfully developed into adults on 20 of the species tested but second-instar larvae developed into adults on 29 of the species tested. First- through fourth- or fifth-instar larvae failed to develop into adults on eight of the species tested.

A nesting aggregation of Lasioglossum (Evylaeus) cooleyi (Crawford) was studied on the campus of the University of British Columbia in July 1988. This species is primitively eusocial. There was a 7.3% size difference between queens and their workers; 40% of the latter had well-developed ovaries and 14% were mated. Thus, this species is one of the most primitively social members of its subgenus. The cells were not gathered together in a cluster or surrounded by a cavity. This species has a haploid chromosome number of 18, the largest number yet recorded for any Halictid bee.

Recent studies have suggested that the stylostome of parasitic larval water mites of the genus Arrenurus Dugès is a product of the mite, not the host. We tested this hypothesis by comparing stylostomes of the similar species Arrenurus novimarshallae Wilson and Arrenurus pseudotenuicollis Wilson formed in each of two mosquito species, Anopheles crucians Wiedemann and Anopheles quadrimaculatus Say: if the stylostome is produced by the mite, not the host, then stylostome form is likely to be constant in different host species parasitized by the mite.

The stylostome of A. pseudotenuicollis is a short, broad, convoluted sac, and stylostomes within the two host species did not differ significantly. The stylostome of A. novimarshallae is a long, thin, convoluted tube, and although it was significantly smaller in A. quadrimaculatus than in A. crucians, its form remained constant. Dark pigment deposits around the stylostome’s attachment point and along the tube may represent host defense that reduces stylostome growth in A. quadrimaculatus. Laboratory-reared A. novimarshallae often die after a brief engorgement period on A. quadrimaculatus but not on A. crucians.

Thus, the stylostome of these two mite species has a consistent form in each of two host species, an observation compatible with the hypothesis that the stylostome is a product of the mite. In addition, the ease of distinguishing these two mite species on the basis of stylostome morphology attests to the potential value of the stylostome as a taxonomic character.

Larvae of Rhyncholimnochares kittatinniana Habeeb are described — the first larval description within the subfamily Rhyncholimnocharinae. The larval instar is apparently wholly aquatic, making members of this genus the fourth lineage within the Hydrachnidia to have acquired this lifestyle independently. Various morphological characteristics of larval R. kittatinniana are adaptations associated with crawling through boundary-layer flow within the gravel of stream beds. Larvae and nymphochrysalids were found attached to the abdominal tergites of elmid beetles within the respiratory airspace.

The species of Limnozetes of northeastern North America are treated. A new generic diagnosis is given. Eight new species are described: L. latilamellata, L. guyi, L. borealis, L. onondaga, L. amnicus, and L. palmerae on the basis of adults and immatures, and L. lustrum and L. atmetos on the basis of adults. Identification of adults and immatures of these species is presented in tabular format. The range of morphological variation exhibited by these species is discussed. Transformation series for eight character states in Limnozetes are hypothesized on the basis of comparison with Hydrozetes. A key is given to the adults of the nine species of Limnozetes recorded from northeastern North America.

Adults of Scapuleremaeus kobauensis gen.nov., sp.nov. are described from British Columbia. The systematic relationship of this genus to other genera in the Cymbaeremaeidae is discussed.

Larvae of Phanocelia canadensis (Banks) were found inhabiting the floating sphagnum fringe of acidic bog ponds. Phanocelia canadensis has a 1-year life cycle with autumnal emergence. This is the first morphological and biological information available for immature stages of this genus.

The mountain pine beetle, Dendroctonus ponderosae Hopk., causes extensive mortality of lodgepole pine, Pinus contorta var. latifolia Engelm., throughout western North America (Van Sickle 1982). The Prince Rupert Forest Region, in the northwest of British Columbia, initiated an aggressive beetle management program in 1981. Logging of infested stands, and winter felling and burning of individual infested trees are the most common direct control techniques.

The “Bristol Lake” infestation developed in the Bulkley Forest District, approximately 55 km northwest of Smithers, B.C., on a steep rocky ridge within the valley of Harold Price Creek. The area contained large volumes of mature lodgepole pine, and control of the infestation was therefore considered critical to the local beetle management plan, but the size (50 ha) and rough topography of the infested area precluded normal direct control measures.