Recent advances in genetic insect control theory have made it important to investigate the fitness effects of, and isolation procedures for, autosomal translocations. We isolated 57 autosomal translocations in Drosophila melanogaster (Dipt., Dros.). Twenty-one were homozygous-viable and a few of these were almost as viable as wild-types. From data obtained during the isolation of these translocations it appears that those translocations whose heterozygotes produce high levels of unbalanced gametes have the same range of homozygous viabilities as others. We may infer, therefore, that it is possible to use our simple marker-free isolation method to isolate translocations with sufficiently low heterozygote and sufficiently high homozygote fitness to make population replacement practicable.

This is confirmed in population cage competition experiments. It appears that between 5 and 10% of induced marker-free translocations may be useful for population replacement.

Female adults of two new species of Trisetacus infesting berries of junipers are described, T. neoquadrisetus from Rocky Mountain juniper and T. batonrougei from eastern red cedar, with remarks on the identity of eriophyoid mites living in juniper berries in North America.

Surveys, from 1948 to 1964, showed that parasites were of minor importance in controlling the European corn borer, Ostrinia nubilalis (Hübner), in extreme southwestern Ontario. Of the three species that became established, Lydella grisescens Robineau-Desvoidy was the most widespread and the most important. Eriborus terebrans (Gravenhorst) showed considerable buildup in parts of Essex County after discovery there in 1957, and Sympiesis viridula (Thomson) was found widely dispersed, but low in density, throughout the survey area. There is an indication that parasites might be of greater importance in areas where the second-generation borer is increasing.

In the description of the Byron Bog (Judd, 1957c) it was pointed out that one method of collecting insects in the bog was to make a circular sweep with an insect net, held at arm's length, through the tops of the bushes in the Chamaedaphnetum calyculatae association. The net used was one with a rim twelve inches in diameter and the radius of the circle over which the sweep was made was six feet. A single sweep was made each day from Itlay 15 to November 15 in 1956 and all the insects collected each day were sorted and counted. The dav of maximum blooming of Chamaedaphne calyculata was May 21 and the day of last blooming was June 1 (Judd, 1958a). Thus there was a period of nineteen days, from May 15 to June 1, when the plants were in bloom while the sweeping was in progress.

Chrysopophthorus has a very wide distribution, occurring in four continents. C. chrysopimaginis Goidanich is placed as a new synonym of C. hungaricus (Z.-Kiss), which is transferred here from Helorimorpha (new combination). The other European species, C. elegans Tobias, is distinguished. Five new species are described; C. americanus from the United States, C. tropicalis, C. caribbeanus and C. brasileanus from South and Central America, and C. orientalis from Malaya.

The biology of Endothenia daeckeana and its relationships to its host, Sarracenia p. purpurea, are described as they occurred during 1980 in the Eastern Townships region of Quebec, Canada. Around 1 July eggs are laid singly on flower bracts of S. p. purpurea and newly-hatched larvae bore into the ovary base to reach the carpels. Instar I larvae enter seeds and eat them from the inside while later instars (II–V) consume seeds from the outside. Instars IV or V overwinter and leave the ovary in September or October and tunnel down the pithy flower stalk to reach their overwintering sites. Pupation takes place in late May in special chambers that instar V larvae have constructed within the flower stalks where overwintering occurred. Adults emerge after pupae push headfirst through the remaining epidermis that covers the pre-chewed exit hole. The sex ratio (proportion females) of laboratory-emerged adults was 0.43. Twenty-five percent of E. daeckeana larvae were parasitized by Scambus spp. or Glypta sp. (Ichneumonidae) and five eggs out of about 300 examined contained the egg parasite Trichogramma ? semifumatum (Trichogrammatidae). Undamaged carpels from pitcher plant ovaries infested with E. daeckeana often had the seeds bound into a hard mass by the fungus Acremonium strictum.

The last instar larva of Hellula rogatalis (Hulst) is described and illustrated. Diagnostic characters of the genus are given, and a key included for the North American species. Larvae of this genus are compared with those of Dicymolomia Zeller.

The apple ermine moth, Yponomeuta malinellus Zeller, is a univoltine pest species that defoliates apple, Malus domestics (Borkh) (Rosaceae), in the temperate region of the Palaearctic. First instars overwinter within a communal hibernaculum beneath the covering of the egg batch (Kock 1998). In spring, larvae emerge to initially mine apple leaves and subsequently feed externally within a communal tent (Menken et al. 1992). During heavy infestations, the communal tents may envelop the entire apple tree, resulting in total defoliation (Parker and Schmidt 1985). There have been several accidental introductions and subsequent eradications of the apple ermine moth in eastern North America (Hewitt 1917; Parker and Schmidt 1985) but, by 1989, the pest was found in the Fraser River Valley in British Columbia, in Whatcom county, Washington, and in northwestern Oregon (Antonelli 1991; Unruh et al. 1993).

The multivariate statistical techniques of canonical correlation and canonical redundancy analyses were used to assess the population structure of larvae of Sitona hispidulus (F.) in alfalfa field soil. A series of rhizosphere variables was correlated with a series of insect variables that represented the developmental stages of the insect to identify relationships between the insect and rhizosphere. Results indicated that 1st and 2nd-instar larvae were correlated with small root nodules and soil moisture, but not with taproot biomass. Third- and 4th-instar larvae and pupae were not correlated with any of the rhizosphere components measured. Fifth-instar larvae were associated with taproot biomass.

Female. Length .03 inch. Head and thorax black. Antennæ 11 jointd, scape and pedicel dilated below, flagellum and club pale brown, funicle joints slender, cylindrical, club greatly and enormously enlarge, not jointed. Legs long, slender, yellow. Abdomen ovate, black shining; petiole slender, yellowish. Wings hyaline, very narrow, with extremely long ciliæ; submarginal vein short; marginal vein punctiform.

Field testing of a large number of synthetic compounds and two-component combinations thereof revealed an attractant for the adult males of Leucania commoides Guenée. Several three-component combinations were tested and the largest numbers of L. commoides males were attracted to Z-9-tetradecen-1-yl acetate, Z-11-hexadecen-1-yl acetate, and Z-11-hexadecen-1-ol in ratios of 4:4:1 to 10:5:2. The attraction of this species was inhibited by Z-9-tetradecen- 1-ol.

The North American species of Choroterpes are discussed and Neochoroterpes n. subgen. is established for C. mexicanus n. sp., C. crocatus n. sp., and C. kossi n. sp. A distribution map is included for the southwestern species of Choroterpes s. str., and distribution map, key to the nymphs, descriptions of the known stages, and figures are presented for the species of Choroterpes (Neochoroterpes).

A computer model was written to simulate the population dynamics of the cabbage aphid, Brevicoryne brassicae (L.), on the host Maris Kestrel kale, Brassica oleracea L., at Vancouver, British Columbia. The model incorporated the effects of temperature, morph determination, plant quality, predators, parasites, and leaf fall. Comparisons of simulated results with field observations indicated that although B. brassicae, Aphidoletes aphidimyza (Rond.), and Diaeretiella rapae (M'Intosh) were reasonably well understood, syrphid predation was not, and appropriate feed-back mechanisms which could prevent monotonic increase or decrease in the simulated population were lacking. A detailed study in which the population dynamics of the prey is accounted for in terms of the numerical and functional responses of syrphid predators is necessary to understand the population dynamics of B. brassicae on Maris Kestrel kale at Vancouver. Comparisons with other aphid systems suggest that a major change in one component of the system can be compensated for by changes in other components. An overview of the cabbage aphid system at Vancouver is given.

Havin been asked by Mr. Jas. Fletcher, of Ottawa, to look for the larva of M. Taylori, with the purpose of discovering its food plant, &c., it was with much pleasure that I accepted the commission, and now have the gratification to inform you of my sucess.

For many years the writer has been endeavouring to obtain collections of Odonata from all parts of Canada as a basis for a study of their distriburion.

Preliminary lists have been published for most of the provinces but very little has hitherto appeared on the odonate fauna of Saskatchewan. The nearest approach to a list of the species from this province is contained in an early paper by the writer ('12b) in which records of nineteen species from Saskatchewan are given.

Bacillus thuringiensis var. israelensis (serotype H-14) and B. sphaericus strain 1593 were tested against Aedes stimulons larvae in the laboratory and in 38-cm-diam, open-ended cylinders embedded in the bottom detritus of a woodland pool. Estimates of LC50 were lower against fourth instars in the field at a mean temperature of 15.9 °C than in the laboratory at 21.1 °C. The greater efficacy in the field was attributed to high daytime water temperatures (mean 20.5 °C) following treatment and exposure of the larvae to substantially greater amounts of toxic material in a larger volume of water than in the laboratory. The regression of probit on log10 concentration was not linear over the entire range of mortality caused by B. sphaericus, increasing the difficulty of estimation of LC values. Bacillus sphaericus was significantly less active than B. thuringiensis.

In the description of the Byron Bog (Judd, 1957a) it was pointed out that Redmond's Pond is situated in the northwest corner of the bog and that during 1956 a tent-trap was anchored in a small bay in the northeast corner of the pond to trap insects emerging as adults from the water. The position of the trap on the pond is shown in the map accompanying the description of the bog (Judd, 1957a) and the structure and use of the trap are also described by Judd (1957b). The trap was placed on the water on May 15, 1956 and remained there until November 8. It was about four feet from the edge of the pond in water about two feet deep. At this point the bottom of the pond was composed of a thick layer of loose, brown peat and the adjacent edge of the pond was occupied by a dense growth of leatherleaf, Chamaedaphne calyculata, growing in Sphagnum (Judd, 1957a). The branches of the bushes of leatherleaf extended out over the water of the small bay in which the trap floated. The only rooted plant growing in and around the trap was spatterdock, Nuphar advena. Floating in the water was a sparse growth of bladderwort, Utricularia vulgaris, and on the surface of the water there were a few scattered fronds of duckweed, Lemna minor, and water flax-seed, Spirodela polyrhiza.

Significant outbreaks of saddled prominent, Heterocampa guttivitta (Walker), have been recorded in northern hardwood stands throughout the northeastern United States since 1907 and were first noted in Ontario in 1938 (Martinat and Allen 1988). The insect overwinters as a pupa beneath litter, adult emergence begins in late May and peaks in mid-June, and oviposition activity ends in early July. Consequently, the major impact of defoliation usually occurs in late summer feeding. Principal hosts are sugar maple, Acer saccharum Marsh. (Aceraceae), American beech, Fagus grandifolia (Ehrh.) (Fagaceae), and yellow birch, Betula alleghaniensis Britton (Betulaceae) (Rush and Allen 1987). Two successive years of severe (>75%) defoliation of sugar maple result in significant growth loss (Bauce and Allen 1991), and heavy mortality may occur to understory sugar maple (Grimble and Newel1 1973). The quantity and sugar content of sugar maple sap are dramatically reduced the spring following heavy (>50%) defoliation (Magasi 1981; Handy 1968). Heavy to severe defoliation may cause crown dieback and defoliation and, in concert with other stresses, may initiate maple decline (Giese et al. 1964). Currently, monitoring and evaluation of saddled prominent populations must rely on egg sampling (Grimble and Kasile 1974), a time-consuming process that is inconvenient for survey personnel and landowners. A sex pheromone has not been identified for this species (nor for any other North American Notodontidae) and would be a potentially useful tool for detecting incipient outbreaks, predicting population levels, and evaluating population trends.

The adults of Phytophaga piceae Felt were described (1) from shoots of white spruce, Picea glauca (Moench) Voss., collected in Manitoba by Swaine in 1926. Felt stated that the shoots suggested the galls of Chermes similis Gill., but he did not describe them. The life-history was unknown. Twigs of white spruce showing damage of a similar nature were collected by Swaine at Fort Coulonge, P.Q., in 1919, but no adults were obtained from this sample.

The efficacy of an extruded plastic trap placed on the ground was measured against plastic-lined trenches used to prevent the colonization of potato fields by walking overwintered Leptinotarsa decemlineata (Say). Laboratory comparisons showed that the original standard extruded trap did not capture as many adult beetles as the plastic-lined trench but that this could be corrected by abrading its surface. Beetles took longer to be trapped by the extruded trap than by the trench and walked away more frequently. The efficacy of the two barriers was unaffected by light simulated rain. Field tests in 1996 and 1997 confirmed that plastic-lined trenches can reduce adult abundance and egg deposition within field even when beetle populations were low. The original extruded trap did not significantly reduce egg deposition. However, it is suggested that a modified extruded trap could be used together with the plastic-lined trench to provide temporary closure of untrenched field sections used for farm equipment access or to surround small fields.