A reinvestigation of the sex pheromone of the eastern spruce bud worm, Choristoneura fumiferana (Clem.), showed that it contains 11-tetradecenal in the ratio 96% trans-: 4% cis-. Field trapping showed the pure trans- compound to be only slightly attractive. Maximum attraction occurred in the range 2% to 5% cis-.

Pre-mating behavior of male gypsy moths was investigated in 0.2 ha circular plots containing from 0 to 72 virgin females/plot in untreated areas and in areas treated with an aerial application of 20 g/ha microencapsulated disparlure. Male moths in both treated and untreated plots oriented initially to trees, not directly to females. Mating was disrupted in treated plots but males continued search behavior. No anemotactic behavior was evident in either treated plots or untreated plots with females. In untreated plots, male moths were not caught on sticky panels (panels suspended at 2, 4, and 6 m) higher than pheromone baited traps set at 2 m. In treated plots, equal number of males were caught at all panel heights and in baited traps at 2 m. Previous mating and pheromone exposure histories of males did not affect the response of these males to traps baited with 4–5 mg of disparlure in untreated plots. In a test of the relative attractiveness of a cotton wick and a new laminated bait dispenser in Johnson traps, traps baited with the laminated dispenser had a greater male moth catch/male contact to trap than the traps baited with the cotton wick. Not all males contacting the Johnson trap were caught. A mode of action for disparlure as a disruptive agent in the long range sexual communication system of gypsy moth is proposed.

Parasitism in natural populations of Hyphantria cunea Drury was measured in New Brunswick and Nova Scotia, 1957–1973. Thirteen parasite species were recovered during this period but only a few caused an appreciable degree of mortality. The per cent mortality showed an immediate rather than a delayed response to host density, the relationship being direct up to a density of about 10 host colonies per mile, then inverse. Possible reasons for this sort of relationship are discussed.

Parthenogenesis in North American mayflies occurs in Ameletus ludens Needham (Clemens 1922), Ephoron album (Say) (Britt 1962), Stenonema fermoratum (Say) (McCafferty and Huff 1974), S. interpunctatum (Say), S. pulchellum (Walsh), and S. vicarium (Walker) (Huff and McCafferty 1974). Attempts to determine its occurrence in the genus Hexagenia are reported for H. limbata occulta Walker (Neave 1932), H. limbata (Serville) (Hunt 1953), and H. bilineata (Say) (Thomforde and Fremling 1968). The purpose of this note is to report hatching in unfertilized eggs of H. rigida McDunnough.

Aphidius smithi Sharma and Subba Rao is the most important parasite of the pea aphid, Acyrthosiphum pisum (Harris), in North America. In 1958, it was imported into the United States from India to control the pea aphid and was subsequently released and recovered in most of continental United States except the Gulf Coast States and Texas (Halfhill et al. 1972). Mackauer and Finlayson (1967) reported that the parasite was present in Ontario, Quebec, and British Columbia and had been released but not recovered in Nova Scotia. A. smithi has never been released in western Canada nor been found on the Canadian prairies before 1970.