A quantitative method is described for measuring the nuisance caused by non-biting aquatic insects (Chironomidae, Trichoptera, Ephemeroptera) in the absence of a human observer. Threshold nuisance densities referring to different human occupations are given; and application of the method is discussed.

Diel periodicities of emergence and oviposition of Trichoptera, observed in the St. Lawrence River at Montreal, Quebec (451/2° N.), in late June and July, are closely similar. They are poorly synchronized but the peak for most species is nocturnal, falling between sunset and solar midnight. Catches in floating traps were used to measure emergence rate. As such catches (of Trichoptera) may contain parous as well as newly emerged females, attempts were made to separate these two components of the catch before analysis, thus providing records for both emergence and oviposition. Oviposition periodicity was studied independently by counting egg-masses on a floating board. Precautions needed for future critical work on emergence are mentioned.

Prionomitus mitratus (Dalm.), Trechnites insidiosus (Crawford), Pachyneuron sp. and Asaphes probably vulgaris Walker are recorded as parasitic in Psylla pyricola L. The first two are primary parasites, the latter two are hyperparasites. All are new records for British Columbia. The biologies of T. insidiosus and Pachyneuron sp. are discussed briefly.

The life -span of Swaine jack-pine sawfly adults was studied under various constant and alternating temperatures and at four different values of relative humidity. Temperature significantly influenced the life-span of both sexes according to a non-linear equation, and relative humidity according to a linear regression. The influence of temperature varied with relative humidity in the case of males but not in the case of females. The life-span of both sexes was shorter at alternating temperatures than at constant temperatures.

A nuclear-polyhedrosis virus disease of Spilonota ocellana (Denis and Schiffermüller) is described. The disease was found in the majority of the Nova Scotia apple orchards sampled in a nine-year survey. Under favorable conditions the disease caused high mortalities but usually less than 10 per cent of a host population was killed by the virus.

Agathis laticinctus (Cresson) killed an average of 25 per cent of late-instar larvae.

A method is described for the laboratory rearing of adult bark beetles and their broods in whole bark. A Petri dish rearing chamber is described, which maintains bark moisture at a relatively constant level for periods of up to two months and permits observation of adults and immature stages.

A key, bibliographies, and synonymies are given for the three species of Steremnius Schoen. S. scrobiculatus (Mann.) is considered a synonym of S. tuberosus Gyll.

Field and laboratory hatching experiments were conducted from 1960 through 1963 with eggs of Camnula pellucida (Scudder) laid in field cages and collected at fortnightly intervals. Before freeze-up, embryonic development usually reached prediapause level in all eggs laid before the middle of August; these eggs were the first to hatch when incubated in the laboratory or when left in the soil outdoors. Eggs laid later than mid-August showed progressively less embryonic development and consequently hatched later. Viability was highest in eggs laid during the latter half of August; those laid early in the season often suffered from desiccation because of their long exposure to dry soil conditions; those laid towards the end of the season showed declining viability caused, apparently, by low temperatures. The percentage hatch was relatively high in eggs laid before the end of August but declined progressively thereafter; those laid in October rarely hatched. Seasonal hatching patterns were largely dependent upon weather conditions; such patterns were rapidly completed when an extended period of hot, dry weather continued through the hatching period, but often extended intermittently over a month or more when weather was unsettled. The typical diurnal hatching pattern, which also closely followed the temperature regime, commenced in the morning at 0900–1000 hours as soil temperatures exceeded 65°F., rising to a peak about 1100–1200 hours when temperatures reached 85°F., and then generally declined during the afternoon. However, during rapidly changing weather conditions hatching frequently started and stopped as skies cleared and again clouded over. Winter kill occasionally may be an important factor in reducing populations, especially when snow cover is removed by a mid-winter thaw and sub-zero temperatures follow.

Hydropsyche corbeti, Cheumatopsyche montrealensis, and Protoptila expositionis n. spp. are described from Montreal, Quebec. A total of 93 forms are listed, three of which are represented only by females and cannot be identified to species. An additional species is recorded only from Chambly, Quebec. Thirty-four genera and 13 families are represented in the list.

The Red River Valley was originally a wet prairie and marsh. Drainage commenced in 1899 and was basically complete by 1907. Intensive grain farming developed. The area was periodically invaded by the Rocky Mountain grasshopper, Melanoplus spretus (Walsh), for over 100 years, until 1902, at which time this species apparently became extinct. Local grasshoppers did not become pests until about 1900, after agriculture was well established. The clear-winged grasshopper, Camnula pellucida (Scudder), and the two-striped grasshopper Melanoplus bivittatus (Say), then became abundant. These grasshoppers bred on the roadsides surrounding each square mile. Road-building and ditching produced slopes of ground favorable for oviposition. The destruction of native vegetation and its replacement by introduced grasses, cereal crops and weeds provided attractive and nutritious food plants and oviposition sites. C. pellucida reached its highest population in 1940 when there was an abundance of Poa pratensis L. and Phleum pratense L. on the roadsides. These grasses are attractive food plants. Poa pratensis is known to be highly nutritious. Both species along with Agropyron smithii Rydb. provided favored egg-laying sites. Although C. pellucida has maintained populations capable of damaging crops and peaks occurred in 1950 and 1961 numbers have not again been as high. This may have been related to a marked reduction in P. pratense and A. smithii. M. bivittatus continued at a high population level because of the abundance of oviposition sites and of preferred food plants. Being a general feeder it was not adversely affected by the change in grass species but benefited by an abundance of the lactiferous weeds, Sonchus arvensis Bieb., Lactuca pulchella (Purse) DC. and Taraxacum officinale Weber.

Comparative studies on breeding and survival of Polygraphus rufipennis (Kirby) in black spruce, Picea mariana (Mill.) BSP., red spruce, P. rubens Sarg, and white spruce, P. glauca (Moench) Voss, indicate that red spruce is the most favourable host. The thicker, more scaly bark of red spruce and the less frequent occurrence of competition for bark space and food by other organisms are considered as contributory to the success of beetles in this host tree.

A search for natural enemies of Hippelates eye gnats in Jamaica and Trinidad in 1963 resulted in the discovery of four pupal parasites, Trichopria nov. sp., Spalcmgia drosophilae Ashmead, a species of Spalangia and Encyrtidae, and one larval parasite, Trybliographa nov. sp., in Jamaica. What were probably phoretic mites of the Acaridiae infested up to 6.1 per cent of the adult populations in Jamaica. No parasitic Hymenoptera were found attacking Hippelates in Trinidad. Parasitization in Jamaica sometimes approached 40 per cent, but overall parasitization with all host exposures considered did not exceed 2.5 per cent. The effect of predators on naturally breeding Hippelates populations in both Jamaica and Trinidad seemed highly significant, and predominant species are listed.

Hyposoter parorgyiae (Vier.) (Hymenoptera: Ichneumonidae), a parasite that emerges from the mature larva of Parorgyia plagiata (Wlk.) (Lepidoptera: Liparidae), was found to have a false cocoon. The twelve specimens examined were collected in Ontario and Quebec, and are in the Canadian National Collection, Ottawa, Ontario.

The temporal pattern of emergence of Anax junius Drury was studied by making standardized exuvial collections in a farm pond near Montreal. Supports available to emerging larvae were restricted artificially in order to standardize the collecting area. Emergence lasted for 30 days (29 July to 27 August 1965), the peak lying between days 10 and 15; A. junius thus behaved as a “summer species” (sensu Corbet 1954). The emerging population comprised about 48% males. No adults were seen flying over the pond except during the maiden flight.

Of the five new species herein described, one is a member of the obtusus group, three belong to the santiago group and the fifth to the thilus group. The discovery of these species extends the known range of the santiago and thilus groups into South America and adds a third member to a small monophyletic cluster restricted to Chile.

Seven indigenous and four introduced species of aphids occur on ferns (Polypodiaceae) in North America. A new species, Macrosiphum cystopteris, is described, and Macrosiphum sleesmani Pepper is designated as type of a new genus Papulaphis.

During the past few years Mr. S. F. Condrashoff, Forest Research Laboratory, Canada Department of Forestry, Victoria, B.C., has been studying the insect pests of Sitka spruce on the Queen Charlotte Islands. One of these is a new species and the description of it is presented here to enable Mr. Condrashoff to describe the larva in a companion paper that follows (Can. Ent. 98: 703–706 (1966), in press).

The tactic and kinetic responses of adult Dendroctonus ponderosae Hopkins were studied under varying conditions of light, temperature, humidity, gravity, and with different visual forms. Newly emerged adult Dendroctonus ponderosae Hopk. were attracted by high light intensity and utilized spot sources of light and surrounding objects, but not polarized light, for orientation. Flying adults were positively phototactic unless warmed above 35 °C; egg-laying adults were negatively phototactic. High temperatures and light intensities increased the frequency of flights. The beetles were negatively geotropic but this could be masked by the attraction to light. Dark objects on a light background were attractive; the size of the object was important while the shape was not.

Temperature influenced orientation to some extent but its influence on rate of activity was far more pronounced; rate of walk followed a linear relationship with temperature. Humidity also affected orientation and rate of walk to some extent, although its effect was usually masked by other environmental factors.

The history of the winter moth, Operophtera brumata (Linnaeus), a geometrid introduced into Nova Scotia, is reviewed and an assessment is made of two introduced parasites: a tachinid, Cyzenis albicans (Fallen), and an ichneumonid, Agrypon flaveolatum (Gravenhorst). Functional response curves of both species are discussed, particularly the atypical S-shaped curve of C. albicans, which demonstrates regulatory properties. Biological control efforts to date have been successful but a virus that appeared in winter moth populations may change initial relationships between the introduced parasites and the host.

Feeding of the potato leaf hopper, Empoasca fabae (Harris), on broad bean caused injury manifested at the cellular level by cell hypertrophy. The action of insect saliva was studied under closely controlled conditions by using cultures of broad bean tissue. The initial feeding experiments are reported and a description is given of the nature of feeding sheaths in tissue culture.

Examination of tissue cultures of broad bean fed upon by the potato leaf-hopper suggested that the nature of the sheath was similar to that produced in organized bean tissue. The sheaths could be recognized by the same criteria–the presence of collar-like deposits on the surface of the tissues, the filiform nature or the sheath, the characteristic red staining of the sheath material and the occurrence of enlarged and empty cells adjacent to the sheath. However, feeding in tissue differed in having no specific direction, and in the presence of pools of secretion sometimes found at the base of the sheaths.