Rhyzopertha dominica (F.) (lesser grain borer, Coleoptera: Bostrichidae) is a major pest of stored grain in the United States, Australia, and most other warm regions of the world. It has rarely been detected in Canadian grain, until recently. To determine the distribution of/R. dominica in western Canada, Lindgren multiple-funnel traps baited with R. dominica aggregation pheromones were placed near grain elevators, feed mills, and farms. Rhyzopertha dominica was found flying outside grain-handling facilities in all Prairie Provinces in 1990 and 1991, with thousands collected in Manitoba, hundreds in Alberta, and less than 100 in Saskatchewan. A few R. dominica were caught in Vancouver and Thunder Bay. None were caught in the traps placed beside two grain elevators in southern Ontario. In Alberta and Saskatchewan, the locations with R. dominica were mainly in the south. In Manitoba, the total number of R. dominica caught at each location was higher in the south than in the north. Rhyzopertha dominica were caught as early as 15 May and as late as 18 September, with the peak numbers for a given location occurring between July and September. No difference in the total number of R. dominica caught per year was found among farms, feed mills, or grain elevators in 1990 or 1991. Sampling of stored grain on three farms showed that two of the eight bins sampled had R. dominica. The possible origins of the R. dominica (importation of infested grain, wind-borne migration from the United States, or an established Canadian population) are discussed.
Plant bugs in the genus Lygus (Hahn) (Hemiptera: Miridae) are sporadic pests of canola, Brassica napus L. (Brassicaceae) and Brassica rapa L., in western Canada and infestations appear to have become increasingly common and severe in recent years. Surveys conducted from 1998 to 2000 identified a "northern" assemblage in the boreal ecoregion that was dominated by Lygus lineolaris (Palisot de Beauvois), with minor representation of Lygus borealis (Kelton), Lygus elisus (Van Duzee), and Lygus keltoni (Schwartz). A "southern" assemblage in the grassland ecoregions was dominated by L. keltoni, with a substantial abundance of L. elisus and L. borealis and with few L. lineolaris in the driest areas. The assemblage from the parkland ecoregion was variable but with few L. elisus. The boreal plains and parkland ecoregions of Alberta had the most serious and persistent infestations of Lygus spp. Relative species composition of the Lygus assemblage at the bolting stage was not related to the overall abundance of these bugs at the early pod stage. Lygus species assemblages were similar in terms of composition and relative abundance at the bolting and early pod stages of canola. A shift in species proportions in favour of L. lineolaris in the north and L. keltoni in the south and a decrease of L. elisus has taken place relative to studies conducted in the 1980's.
Can. Ent. 11 1: 681-688 (1979) An open arena, airflow olfactometer was developed and used to test the response of adult Cyrptolestes ferrugineus (Stephens) to various volatile stimuli. Beetles of mixed age and sex oriented positively upwind to the odor of beetles, frass, pentane extracts of frass, and pentane extracts of Porapak Q-captured volatiles from beetles or frass. Both sexes responded to the odor of beetle populations of mixed sex as well as to the odor of males, indicating that males produce a true population aggregation pheromone. Only females responded to the odor of females. C . ferrugineus may utilize the aggregation pheromone in conjunction with fungal odors to locate suitable habitats.
Adults of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), were placed on the surface of grain in plastic cylinders. After 48 hours records were taken of the number passing through a perforated brass screen at the bottom of the cylinders and into petri dishes containing wheat inoculated with different species of fungi. More adults were found in dishes of spoiled grain containing a mixture of fungi than in empty (control) dishes or dishes with water. The largest number were found in dishes containing Penicillium corymbiferum and the second largest number in dishes with Scopulariopsis brevicaulis, Fusarium sp., and spoiled grain. The least number occurred in dishes with Streptomyces sp., uninfected wet grain, or dry grain. The response to fungi is probably induced by olfactory stimuli from volatile compounds in the fungi or by-products of fungi.
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