A dark green aphid was isolated from a greenhouse colony of green peach aphid, Myzus persicae (Sulzer), in Fredericton, N.B. The green aphid was shown to conform taxonomically and biologically to the recently named species Myzus nicotianae Blackman, except for its rare production of alatae. It is reported for the first time on greenhouse-grown potato where its population development is similar to that of the yellow holocyclic M. persicae from the same colony. The vector efficiency of the green and yellow aphids for potato virus Y0 is similar. The yellow aphid tends to be more susceptible to insecticides than the green aphid. Myzus nicotianae was not found in aerial aphid samples taken in New Brunswick in 1967 and 1987.

Massive quantities of webbing and overwintering eggs produced by Schizotetranychus schizopus (Zacher), covering the trunks of two willow trees growing near Radium Hot Springs, British Columbia, are reported. This was the most extensive concentration of overwintering eggs and webbing, produced by spider mites under natural conditions, known to the authors.

The life stages of Macroglenes penetrans (Kirby), an egg–larval parasitoid of the wheat midge, Sitodiplosis mosellana (Géhin), are described. The mean length and width, respectively, of 25 parasitoid eggs deposited in host eggs were 0.105 ± 0.008 (SD) mm and 0.041 ± 0.006 mm. Mature oocytes were 0.131 ± 0.008 mm long by 0.038 ± 0.004 mm wide, slightly larger than laid eggs.

A frequency distribution of head width (HW) indicated two larval instars during the feeding period. During development, the HW of the first instar remains almost constant at about 0.03 mm whereas body length (BL) increases from about 0.15 to about 0.3 mm. Both HW and BL increase in the second instar from about 0.15 and 0.49 to 0.34 and 1.05 mm, respectively, for mature larvae. The third instar does not feed and is characterized by hook-like "pseudomandibles" and four incurving spines on the terminal segment. The pupa is adectious exarate. Adults are about 2 mm long, shiny bluish-black, and have translucent wings. Males have prominent rust-coloured eyes; eyes of females are less prominent and fuscous.

Halictus rubicundus (Christ) is a primitively eusocial halictine bee. Studies of electrophoretic variation at 48 loci for 37 enzymes with an average of 38 bees per locus provided an expected heterozygosity of 0.038 ± 0.018 for a population from Vancouver, B.C. This value is well within the range found for other primitively eusocial bees and wasps. Comparisons of allozyme mobilities made among samples from France, Alberta, and Vancouver indicated that there are some genetic differences, with the French sample appearing particularly distinct. The loci Diaph, G3pdh-1, and 6Pgd-1 had variants with both alleles at high frequency within the Vancouver population. These loci could provide good estimates of the average relatedness between nest mates.

The effects of fenoxycarb, ethyl[2-(p-phenoxyphenoxy)-ethyl]carbamate, an insect growth regulator with juvenile hormone activity, on reproduction in Ips paraconfusus Lanier were investigated. Topical treatment of either females or both sexes of parent beetles with 50 μg of fenoxycarb per insect resulted in a significant reduction in hatching of eggs and numbers of progeny produced by beetles allowed to infest logs of ponderosa pine, Pinus ponderosa Laws. When pairs of beetles were allowed to attack logs that were surface-treated with fenoxycarb, the effects on reproduction at a dose of 100 μg/cm2 of bark surface were comparable to those of a topical treatment at a dose of 50 μg per insect. However, at doses of 1000 or 10 000 μg/cm2 the adverse effects included reductions in the length of egg galleries, fecundity (number of egg niches), and number of freshly laid eggs. Percentage reductions in progeny were 35.8, 82.5, and 95.7 for doses of 100, 1000, and 10 000 μg/cm2, respectively, if brood beetles were allowed to emerge from the logs. This study indicates that fenoxycarb acts as an effective chemosterilant on I. paraconfusus.

Predation of gypsy moth larvae, Lymantria dispar L. (Lepidoptera: Lymantriidae), by ants was observed by placing caterpillars on the forest floor and waiting for ants to find them or by placing caterpillars very close to foraging ants. Over 80% of contacts with caterpillars were made by Formica spp. The rate of successful capture varied with caterpillar instar, generally becoming lower as larvae became larger. However, neonates were successfully attacked by ants less often than first-instar larvae that had fed. Neonates probably have developed defenses that prevent excessive predation because many fall to the forest floor when dispersing. The distribution of time intervals between encounters of ants with larvae was adequately fit by an exponential distribution having a mean waiting time of 20 min. This distribution was used to construct a simulation model of gypsy moth larval predation by ants. Based on the model results, ant success rate, ant foraging density, and residence time of larvae on the forest floor were important determinants of mortality caused by ants.

Drift of aquatic insects was compared at three sites downstream (21, 38, and 107 km) from methoxychlor treatment (0.3 mg. L−1 for 15 min) of the North Saskatchewan River, relative to an upstream untreated site. Species of Diptera (Simuliidae), Ephemeroptera (Baetidae, Heptageniidae, Ephemerellidae, Ametropodidae, Metretopodidae, and Tricorythidae), Plecoptera (Perlodidae and Chloroperlidae), Trichoptera (Hydropsychidae and Hydroptilidae), and Hemiptera (Corixidae) were studied. Drift responses differed depending on species, distance from the injection site, and time after methoxychlor injection. Exposure to methoxychlor initiated catastrophic drift of aquatic insects at all downstream sites. Of 22 species compared before treatment and following methoxychlor injection, post-treatment drift of 17, 21, and 13 species significantly exceeded pre-treatment drift at the km 21, 38, and 107 sites, respectively. Methoxychlor treatment initiated or increased drift of several normally non-drifting species. Similar drift patterns were observed among closely related taxa during the catastrophic phase. For all species studied, comparisons of 24-h drift densities between days preceding and following the catastrophic phase of treatment indicated significant post-treatment drift density increases or decreases at one or more of the downstream sites, but not at the untreated site. Species were classified according to their drift responses to methoxychlor treatment. Factors that may have caused different drift responses among species are discussed.

The spatial distribution of spring and summer populations of the potato flea beetle, Epitrix cucumeris (Harris) (Coleoptera: Chrysomelidae), on potatoes (“Superior” variety) was studied in 1987 and 1988. Slopes of the regression of mean crowding on the mean number of adults per plant were not significantly different from 1.0 except for summer populations in 1988. The y-intercepts of these regression equations were not significantly different from 0, suggesting that adults of the potato flea beetle are not aggregated. The ratios of mean crowding to mean number of adults per plant were 0.81 for spring populations and 1.02 for summer populations, also indicating that the populations were not highly aggregated. With a level of precision of 0.25, 10 samples per plot were appropriate when more than 2.8 adults per plant were present in the spring and when more than 7.2 adults per plant were present in the summer.

Morphometric analysis of 16 body measurements of migratory and solitary Melanoplus sanguinipes (F.) and M. spretus (Walsh) was used to determine if M. spretus was, in fact, the migratory phase of M. sanguinipes. Migratory M. sanguinipes was found to be more similar to its own solitary phase than to M. spretus. Melanoplus spretus resembled migratory M. sanguinipes, but in 14 comparisons M. spretus differed significantly from both solitary and migratory M. sanguinipes. Despite the potential for environmental variation obscuring differences in morphology, the divergent morphometric characters of M. spretus and the phases of M. sanguinipes appear to justify the status of M. spretus as a true species.

The effectiveness of seven insect juvenile hormone analogs (JHAs) in disrupting metamorphosis of the eastern spruce budworm, Choristoneura fumiferana Clemens, was determined by applying the compounds topically to early sixth-instar larvae and monitoring subsequent development. Fenoxycarb showed promising control potential, with an LC50 of 0.26 μg per insect. Relative lethal effectiveness, based on LC50 values, was Fenoxycarb > ZR9892 > ZR8487 > S-71639 > methoprene > ZR9582 > ZR10151. Some of the JHAs tested may be useful in an integrated spruce budworm control program.

The immature stages of Athrycia cinerea (Coq.) including the egg, three larval instars, and the puparium are described and illustrated. The male and female reproductive systems are also illustrated and described and notes on oogenesis are provided.

We have developed a system for recording and quantifying animal behavior on artificial or natural substrates. The system is designed for subjects such as insects and mites with movement rates as high as 4 cm/min. The principle is the same as in automatic stage or sphere centering devices (Berg 1971; Kramer 1976; Thiery and Visser 1986), but the compensations are made manually by an observer who may also simultaneously enter codes for specific behaviors on a microcomputer keypad. Data files produced are analyzed or plotted using programs in SAS® (SAS Institute 1985a) or similar data analysis packages.

The tarnished plant bug, Lygus lineolaris (P. de B.), is the dominant mirid in crops grown in eastern North America (Strong 1968; Bariola 1969). Lygus lineolaris is an ubiquitous species found on a wide range of wild plants and cultivated crops (Knight 1941).

All previously known egg parasitoids of Lygus spp. were mymarids in the genera Anaphes, Erythmelus, and Polynema (CIBC 1979). The mymarid Anaphes iole Girault is the principal egg parasitoid of Lygus spp. in the United States (Debolt 1987). It has been reported from British Columbia, Alberta, Ontario, Quebec, and the Northwest Territories(Huber and Rajakulendran 1988).