Parasitoid-host records were gathered during a study of the arthropod fauna of alfalfa Medicago sativa L., at Ithaca, N.Y., during 1966-71, Dates and number of rearings are given for 46 parasitic taxa. Nine new parasitoid-host relationships are reported.

Selected insecticides were topically applied to different populations of the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough). For each insecticide, the hypothesis of equal response curves was rejected by the likelihood ratio test. Even for two successive generations of the same populations, the hypothesis of equality was not accepted for some insecticides. Chemical control programs directed at different populations of this insect may be adversely affected by such variations.

Southern pine beetles, Dendroctonus frontalis Zimmerman, often carry mites as they emerge from host trees. At least 14 species of mites are phoretic (Moser and Roton 1971). But for D. frontalis, it is not clearly known where in the host tree and at what stage of the beetle's development the mites attach themselves. After the beetle larvae construct oval feeding cells, they develop in three stages: pupa, callow adults, and brood adults (Fig. 1). In trees with thick bark, the larvae bore into the outer bark from within, construct pupal cells, and pupate. But in trees with thin bark, the larvae pupate directly in the larval cells next to the xylem. Thus, the larval galleries in either case are in the living phloem adjacent to the sapwood.

Baumann (1976) lists the zoogeographic range of the Nearctic “winter” stonefly genus Allocapnia as being confined to Eastern North America and the Palaearctic genus Taeniopteryx Pictet as being Amphinorth American (i.e. distributed in the east and west of the continent but not in middle). Allocapnia has never been recorded west of Ontario, in Canada, and although present in some of the east-central states of the U.S.A. (Ross and Ricker 1971) has not been collected in the north flowing Red River system. Taeniopteryx is represented on the Prairies by two species, T. parvula Banks recorded from Aweme, Manitoba and T. nivalis (Fitch) from Alberta (Ricker and Ross 1968).

A re-investigation of the taxonomic status of Bombus sandersoni Fkln. is described. Using multivariate analysis of wing venation data taken from previously identified museum specimens, a non-overlapping separation between sandersoni, B. frigidus F. Sm., and B. vagans F. Sm. was obtained. The Cresson lectotype of B. couperi appears in some respects intermediate between frigidus and sandersoni. Therefore the authors advocate retention of sandersoni as the valid name for the species, while admitting the possibility that this taxon may turn out to be a clinal variant of frigidus.

Males and females of Phlebotomus vexator occidentis Fairchild and Hertig and P. aquilonius Fairchild and Hardwood were collected from burrows of yellow-bellied marmots, Marmota flaviventris nosophora Howell, in southern Alberta. P. v. occidentis adults were collected from burrows at collecting sites at Police Coulee (111°39′ W. long., 49°3′ N. lat.) and Lethbridge (112°52′ W. long., 49°39′ N. lat.), whereas P. aquilonius adults were collected only at the Police Coulee site. The Lethbridge location is a new northern limit for distribution of P. v. occidentis. The seasonal occurrence of adults of P. v. occidentis is July to September and P. aquilonius is August to mid-October.

Acaronemus n. gen. is described, and its type-species, Tarsonemus destructor Smiley and Landwehr, 1976, is reillustrated. Other, undescribed species of Acaronemus are discussed briefly. Members of this genus are unique among the tarsonemid mites as known to date in preying on mite eggs.

While there is much evidence for interrelationships between the organic components of insect diets as they relate to growth, there is very little information available on inorganic or organic-inorganic relationships. An example of inorganic interactions is found with Cu and Zn in the house cricket, Acheta domesticus (L.) (McFarlane 1976a).Organic-inorganic interactions have been shown by Fraenkel (1958), who demonstrated effects of Zn and potassium on the expression of a carnitine deficiency in Tenebrio molitor, and by McFarlane (1974), who showed an interaction between Cu and vitamin E in the house cricket.

The water boatman Cenocorixa expleta (Uhler) is an inhabitant of saline ponds in the interior of western North America (Jansson 1972; Scudder 1976). In a field survey, Scudder (1969a) failed to find this species in ponds with surface conductivities less than 3900 μmhos/cm. Although it is apparently absent from fresh water, the osmotic responses of C. expleta are essentially those of a fresh water insect (Scudder et al. 1972). Also, salinity tolerance experiments carried out by Scudder (1969b) show that at 15°C adults of the species can survive almost a month in fresh water (less than 800 μmhos/cm) without food. However, it has not been shown that C. expleta can actually develop and breed successfully in fresh water.

The eggs of Nabis alternatus Parshley, which are laid in the stems of alfalfa plants, can be identified by their opercula, which protrude from the stem. Most eggs were laid in the upper portion of the main stem where the mean widths of the stems were 1.5 to 1.7 mm, and the hardness averaged 7.4 kg. The mean and minimum heights of oviposition increased with increasing total height of stem and the number of eggs laid also increased. Eggs laid in alfalfa stems that were subsequently allowed to dry had low percentage hatch.

The apple leaf midge, Dasineura mali (Kief.), was first noted in a New Brunswick commercial apple orchard at Waweig, Charlotte County, in 1964. Adults collected there in 1965 were identified by Biosystematics Research Institute. The midge's first appearance in the Saint John River Valley was in 1968 in York County. Since 1968 this insect has spread to infest orchards up river as far as Woodstock and down river to orchards in the Gagetown-Queenstown area.

During the course of a continuing investigation on egg structure in various insect orders by one of us (EHS), the eggs of some species of Hymenoptera became available for examination with the scanning electron microscope. In this note we report a re-examination of the micropylar region of the egg of the ichneumonid parasitoid Pimpla turionellae (L.) which was originally described by Bronskill (1959), and compare the morphological features of this region with those observed on the same region of the egg of the honey bee, Apis mellifera L. Because of their extremely thin and flexible chorions, the eggs of both species must be freeze-dried to maintain their normal shape in the vacuum of the microscope. They were glued to thin glass coverslips with a dilute solution of Scotch tape - chloroform adhesive, immediately frozen on dry ice, cut in half and freeze-dried for about 16 h at –70°C. The coverslip was mounted on a metal stub with conductive paint and gold-coated just prior to examination in a Cambridge Stereoscan MKI1A.

This note reports the first in vitro oviposition and rearing of a parasitic insect, the endoparasitoid wasp Itoplectis conquisitor (Say), a male, on an artificial host consisting of an encapsulated synthetic, or meridic (Dougherty 1959, p. 53), medium.

Parasitic insects, of course, have been reared in vitro on meridic diets (House 1954; Yazgan 1972; Thompson 1975). Some were reported to oviposit into artificial objects (Arthur et al. 1972; Rajendram and Hagen 1974; Hoffman et al. 1975). Trichogramma pretiosum Riley laid viable eggs and development to adults occurred in small wax-resin spheres filled with host haemolymph (Hoffman et al. 1975).

Clastoptera arborina Ball is placed as a senior synonym of C. newporta Doering. C. doeringae n. sp. is described for the species previously reported as “arborina” by Doering (1928).

Winter cocoons have been described in several species of Chironomidae (summary in Danks 1971, table V; see also Madder et al. 1977). The larvae are tightly folded within these closed cocoons in ways more or less characteristic of the species. Usually the walls of the cocoons are thicker than those of the tubes within which larvae are active in summer and less particulate matter is incorporated into them. Most larvae of two species studied earlier in Ottawa (Danks 1971) constructed their winter cocoons only after surface ice had formed.

In “higher” flies (e.g. Musca dornestica L.), a pair of large air-sacs is found in the anterior region of the abdomen (Hewitt 1914). The main function of these air-sacs appears to be to maintain the extended external shape of the abdomen in newly emerged flies, because as the fat-bodies in both sexes, and also eggs in the female, grow, these air-sacs decrease in size, thus allowing room for these growing organs (Evans 1935). These air-sacs, and those elsewhere in the thorax and head, were believed to give buoyancy for insect in flight, to reduce the volume of circulating blood, and(or) increase the volume of the “tidal air” which is renewed at each respiration (see Wigglesworth 1965 for review). In our recent studies on the feeding of S. calcitrans, we noted that the change in the size of the abdominal air-sacs, besides making room for the growing abdominal organs, may minimize change in abdominal volume during feeding and digestion.