The alfalfa plant bug, Adelphocoris lineolatus (Goeze), a well-known pest of alfalfa in Europe and the United States, was first recorded in Saskatchewan in 1947, in the Hudson Bay district about 16 miles west of the Manitoba border. By 1959 it had spread westward through the northern agricultural area of the province to within 35 miles of the Alberta border. Economic infestations appeared within two to four years of its initial occurrence in each district.

The migratory behaviour of the adult, which is apparently essential for maximum reproduction, effects rapid dispersal of the species. Also, because of this migratory behaviour control measures may have to be undertaken each year, and seedling stands may be infested in the first crop year.

The seasonal development of the insect is described. Apparently in the spread of the insect northward a univoltine population is being selected. Eggs that have overwintered in stems hatch in late May and early June. Development proceeds through five nymphal instars, and adults begin to appear toward the end of June. These adults lay eggs during the latter part of July. Most of the eggs enter diapause: less than five per cent of them hatch the same year, and any second-generation adults that do occur do not have time to mate and lay eggs before all activity is halted by freezing weather.

The main host plants of A. lineolatus are two cultivated legumes, alfalfa, Medicago media Pers., and red clover, Trifolium pratense L. No native host plants have been found in Saskatchewan.

About three per cent of field-collected nymphs from the Nipawin district were parasitized by braconid larvae tentatively identified as Euphorus pallipes (Curtis).

The genus Cremifania Czerny combines characters of various taxa which Hennig (1958) placed in two superfamilies, the Sciomyzoidea and the Lauxanioidea. In some ways it can be considered a taxonomic link between the two groups. Important characters of the genus are compared with homologous characters in related families and its taxonomic relationships are discussed. At the same time, a family tree for the major families assigned to both superfamilies is suggested.

Cremifania does not fit well in any family as they are now defined, but, because it fits best in the Chamaemyiidae, that family is redefined to embrace the genus. The family is then divided into two subfamilies, the Cremifaniinae, new subfamily, for Cremifania, and the Chamaemyiinae comprised of two tribes, the Chamaemyiini and Leucopini, new tribe; a key to all the suprageneric categories is presented.

A new Cremifania, the second known species of the genus and the first Nearctic one, is described from New Mexico.

The surviving material of C. F. Baker's collection of aphid parasites comprises a total of 107 specimens of which 27 are syntypes representing 9 species described by Baker. Lectotypes are designated for Ephedrus californicus, E. nevadensis, Praon nanus, P. occidentale, Aphidius delicatus, A. coloratus, A. ferruginosus, A. pulcher, and Diaeretiella (= Diaeretus sensu auctt.) californica. The synonymy of all taxa is discussed, and redescriptions of most of the species are given. The remaining 80 specimens of the collection represent 7 genera and 14 species.

Tetralopha vacciniivora, new species, is described from material reared at Cedar Lake, Ontario, by officers of the Department of Forestry of Canada. The new species is compared with the poplar-feeding T. aplastella (Hulst), the maple-feeding species identified as T. asperatella (Clemens), and the oak-feeding T. expandens (Walker). T. nephelotella (Hulst) is sunk as a synonym of T. expandens.

The structure and position of the spiracles in Sitophilus granarius and Tribolium confusum adults was studied. On the basis of this an attempt was made to explain the differences in water loss from these two species under reduced pressure. It was concluded that the spiracular structure combined with the inflation of the body under very low pressures, can account for the apparently anomalous water loss results.

The myzaphidines in Canada consist of three genera and seven species of which two are described as new. Myzaphis v. d. G. is recorded from North America apparently for the first time and one endemic species is described. Keys and brief descriptions of the genera and viviparous forms are offered. Pentatrichopus Borner, which includes the economically important pests of strawberries is considered a synonym of Chaetosiphon Mord. Chaetosiphon is retained as a genus only because of its association with Rosa spp., Potentilla spp., and Fragaria spp. The presence of five setae on the basal tarsal segments, which was the only means by which the myzaphidines could be distinguished from other capitophorine aphids, is no longer valid. C. fragaefolii, which has been considered to be a complex of two species, is treated as a single species. The conspicuous variation in the arrangement of dorsal abdominal setae and in the tarsal setae is readily explained by neotenic development which probably only indirectly affects the development of the setae.

The phytophagous mite Oligonvchus bicolor (Banks) has been observed feeding on red oak, Quercus borealis Michx. f., at Kentville, N.S. It has not previously been reported in Canada east of Ontario. McGregor (1950) reported this mite as being found on chestnut, hickory, maple, oak and spruce in Connecticut, New Jersey, New York, North Carolina and Washington. Pritchard and Baker (1955) studied specimens taken from oak at Ithaca, N.Y., red oak at Hamden, Conn. and Washington, D.C., willow oak and white oak at Durham, N.C., and pin oak at Lawrence, Kansas. Garman (1923, 1940) found it common on oak and also present on chestnut, maple, hickory and birch. Johnson (1956) reported O. bicolor fairly common in Connecticut and believed its distribution to be the east coast of the United States. He stated that it was the most important mite species on chestnut in Connecticut and that when present occurred in large numbers. Caesar and Ross (1921) found O. bicolor heavily infesting ornamental oak trees in different parts of the Niagara district of Ontario.

In the past twenty years in Saskatchewan the rate of nymphal development of three species of grasshoppers has varied considerably from year to year and region to region. Camnula pellucida appeared as early as, or earlier than, the other two species. The average date of attainment of the adult stage was July 21 compared to August 4th for Melanoplus bilituratus and M. bivittatus. Adult surveys in Saskatchewan have generally coincided with the time when the dominant species of grasshoppers, in any region, have attained full morphological and sexual maturity and have had an opportunity to disperse and stabilize density. Duration of the surveys, in any one of seven regions, in the years 1958-1961, varied from 4-31 days and averaged 19 days per year. The total period of survey for the province varied from 25-42 days and averaged 30 days per year.

Variations in seasonal histories of the several grasshopper species demand an elastic schedule for surveys. The concept of maintaining a standard and rigid “best time” for surveys is untenable in the light of the present investigations.

Parasites of the sawflies Neodiprion abbotii (Leach), N. abietis (Harr.), N. lecontei (Fitch), N. nanulus nanulus Schedl, N. pinetum (Nort.), N. pratti banksianae Roh., N. swainei Midd., and the N. virginiana Roh. complex are separated by using characters of the parasite remains in the host cocoons from which the parasites emerged. Characteristics of the cast skin of the last larval instar of 11 species are described and illustrated in this paper; the remaining 29 species were described and illustrated in earlier papers (Finlayson, 1960a, 1960b, 1962). Keys are given to separate the species of the genera Exenterus and Lamachus that attack the above hosts, using characters of the cast skin of the last larval instar.

Collections of aphids on cereal grains and grasses in Manitoba were made during the years 1958-62. The species collected are important because of their possible economic injury to cereal crops and also because several of the species are known vectors of the barley yellow dwarf virus of barley, oats and other Gramineae. Bruehl (1961) listed all known hosts of the virus, mostly determined in greenhouse inoculation trials. He emphasized the importance oi the feeding habits of aphids under natural conditions in the field. In 1962 most species of aphids on Gramineae were present in unusually large numbers in Manitoba, and an excellent opportunity was afforded to obtain records of breeding colonies on 38 host plants, many of them in the Forage Plots of the Department of Plant Science, University of Manitoba. The host plants and aphids are listed in Table I. The aphid species were determined by W. R. Richards, Entomology Research Institute, Ottawa, or by the senior author.

Over 5,000 cargoes of grain, grain products, oilseeds, oilseed products and pulses from Canada were examined between 1953 and 1959. Only a few cargoes were found to be infested and there was a general decline in infestation over this period. Many of the insects recorded were acquired from the structure of the ships but mites were more frequently introduced with the grain. The miles which occurred most frequently were Acarus sira, Glycyphagus spp. and Cheyletus spp.; the commonest insects were Psoeopreri and Cryptolestes spp. Including those species derived from residues in ships, the total of species and species groups recorded was 77. Cases where insects have been derived from infested residues in the ships are described. A greater variety of species is to be found on Western Canadian, than on Eastern Canadian grain. This appears to foe due to the damp conditions brought about by overstowage of the grain with lumber and the consequent high proportion of mycetophagous species. The incidence of most grain-infesting insects and mites declined steadily during the examination period

An artificial key is presented to separate the second to fourth instar mosquito larvae of eastern United States and Canada, west to and including Texas and Manitoba. A second, natural key, separates the genera and many of the subgenera. A list of the 134 included species and subspecies with their ranges within this region is given, with indicated corrections since Carpenter and LaCasse (1955) and the Stone et al. (1959) catalog. Larvae of two species are unknown.

The aphids described in this paper are referable to the genera Acyrthosiphon Mordvilko and Macrosiphum (Sitobion). The Canadian representatives of these two groups can be distinguished by means of the keys offered below.

In its territorial behavior, the “tricolor” form of Hetaerina titia differs markedly from both typical H. titia and H. americana. Territoriality between “tricolor” and americana males is initiated only by the latter, and affects the spatial structure of a breeding population of “tricolor” males. Territoriality between americana and typical titia is initiated by either species, and usually leads to displacement of the americana male; this has no visible effect however on the population structure of americana.

H. titia and the “tricolor” form are suggested as separate species because of: (1) differences in breeding and territorial behavior (in both intra- and interspecific flights), and differential habitat selection by females for opposition. (2) existence of different and consistent female body color patterns and the breeding of these females with their specific male type. (3) the strong likelihood that the male wing color patterns are genetically governed with the implication that genes are not interchanged between titia and “tricolor”.

During studies on blood circulation in the wings of insects it was observed incidentally that the pterostigma (“stigma” of some authors) in some insects had little in common with the similarly-termed structure in others. At the same time some of them were structurally similar to areas not generally identified as pterostigmata in the wings of other species. In view of the general recognition of pterostigmata as an obvious feature in certain insect wings, the apparent mis-interpretation of their nature, and their possible significance in wing evolution, it seems useful to comment on their structure and possible origins.

Emergence in the laboratory at 80°F. of apple maggot adults from pupae overwintering outdoors was compared at different times of the dormant period and with emergence from pupae stored at 37-40° for all or varying parts of the dormant period. Shorter incubation times were required for emergence when pupae from outdoors were placed in incubation in autumn, one to three months after larval maturity, than during winter or early spring. Exposure for at least six weeks to low temperatures, either outdoors or in the laboratory, at first increased the incubation time required for emergence. Later the required incubation times of insects overwintering outdoors or in the refrigerator decreased as the duration of exposure to low temperature (or duration of dormancy) increased. But no such decrease was evident in samples of pupae held at 37-40°F. for periods longer than six months. Comparison of emergence from pupae from outdoors with those stored at 37-40°F. when incubated in spring and early summer showed that outdoor temperatures before June 1, in 1959-61 at least, had no effect on the subsequent emergence from pupae overwintering outdoors. When incubation at 70°, 75°, 80°, 85° and 90°F. was compared, the times required for emergence decreased with increased incubation temperature up to 85°F. However incubation at 90°F. resulted in a decrease in the percentage of incubated insects that emerged as adults.

At least 25 species of Carabidae were caught in pitfall traps in a DDT-sprayed Ontario peach orchard, the commonest being Pterostichus melanarius (Ill.). Harpalus pennsylvanicus (Dej.), Agonoderus lecontei Chd., Amara (Curtonotus) pennsylvanica Hayw., Anadaptus sanctaecrucis (F.) and Anisodactylus rusticus Say. Fewer P. melanarius were caught in plots where foliar sprays of DDT were used most recently, but a rather large and varied population of carabids persisted in all plots despite the application of DDT for as long as ten years.

The immature stages of five Canadian species of Pero Herrich-Schaeffer are described. These species arc P. bebrensarius Packard, P. bonestarim Walker, P. mizon Ritidge, P. morrisonaius Henry Edwards, and P. occidentalis pnckardi Cassino and Swett. Three colour patterns have been noted in the larvae of P. mizon and P. morrisovarius but only nne in each of P. behreniarius, P. bonestarius and P. occidtmtalis packardi. Brief accounts of the life histories and habits of the species are presented together with a key to the mature larvae.

During the course of a study of the bionomics of the pitted ambrosia beetle, Corthylus punctatissimus Zimm., in southern Ontario in 1959, the method of overwintering fungal spores and their transmission from brood galleries to healthy plants by the beetles was determined. This process was not clearly understood with respect to any of the ambrosia beetles until recently when Francke-Grosmann (1956) described in detail the different structures, present in several species of Platypodidae and Scolytidae, used in storing fungal spores. In Scolytidae she found that the females of some Trypodendron species store spores in tube-like structures within the prothorax (invaginations of the prothoracic wall); that females of Xylosandrus germanus Bldf. and Anisandrus dispar Fabr. keep spores overwinter in shallow pouches in the intersegmental membrane between the pronotum and mesonotum; that females of Xyleborinus saxeseni Ratz. store them in a small cavity at the anterior edge of the elytra; and that females of Xyleborus pfeili Ratz. store the spores in a receptacle on the “posterior” abdominal tergite. In some species of Platypodidae she found somewhat similar structures in both males and females. In 1959 Fernando (1959) described spore storage by the shot-hole borer, Xyleborus fornicatus Eichh. He found that females store spores in sacs on either side of the head, situated anterior to the brain, and that the sacs open by ducts into the upper part of the oral cavity.

In this paper a new species of Fullawaya Essig is described. The genus is broken down to include subgenera Neopterocomma H.R.L. and Pseudopterocomma new subgenus. The species Fullawaya saliciradicis Essig and Pterocomma braggi (Gillette and Palmer) are discussed.