No abstract

Can. Ent. 100: 1179Ent. 100: -1199Ent. 100: (1968 The adult Arthropoda occurring in, on, or emerging from 2,660 sporophores of the bracket fungus Polyporus betulinus (Bull.) Fr., growing on dead birch, are listed. Collections were made in New Brunswick, Quebec, Ontario, and Manitoba. Two hundred and fifty-seven species of Arthropoda, mainly insects and mites, were recorded; over 49,000 specimens were examined. Old, twice-wintered sporophores produce more species and more individuals. In general, the fungus is rich in species but rarely produces sizable populations of any one species. HelodidaeCyphnn sp. CryptophagidaeCrosimus nbestilus Csy. LathridiidaeCorticarba sp.Lotl~rtdirrs t onsinilir Mann.

The fauna of the sporophores of the perennial bracket fungus Fomes fomentarius (L. ex Fr.) Kickx were examined in a 3-year study. One species of molluscs and more than 152 species of arthropods excluding mites, representing 13 orders, 70 families, and 5400 individuals, emerged from or were found on or in, 1448 sporophores detached from dead birch trees; the sporophores were collected each year in Gatineau Park, Que., kept individually in screen-topped glass jars in a laboratory, and examined for several months. Mites, which were recorded quantitatively only in the final year, added 4 orders, 19 families, and 30 species to the preceding totals. Mites were the most frequently occurring and probably the most numerous arthropods, followed by Coleoptera, Psocoptera, Collembola, Hymenoptera, and Diptera.The key organisms of the fauna were five species of beetles that were primarily responsible for tunnelling and destruction of the sporophores and would therefore exert great influence on the composition of the community. Their tunnels provided shelter and food for many smaller arthropods or facilitated their feeding. Some beetle species tunnelled the sporophores for one season and others, for several, but many living sporophores and most dead ones tunnelled by beetles were tunnelled in the same season by more than one species of beetles.There was considerable latitude in types of sporophores inhabited by various arthropods but some species were particularly attracted to living or dead, to younger or older, and to smaller or larger, sporophores. Some species were also attracted to certain regions of the sporophore more than were other species.Possible economic implications of observations made in the study are discussed.

No abstract

Examination of a l a r~e number of 100-leaf samples shows that the European red mite is distributed contagiously, not randomly, on leaves of apple trees. When the mean number or mite9 pr-r leaf is plotted aaainst the proportion of mite-fmc leaves for the correupondin~ sample, thc points fall in a narrow zone, steepest: and narrowest a t the lower densities. Following application of miticides to heavily infested t r m , it is usual to s~ttrlrnarize thc firldings of the tests by gmding the performance n i the chemicals as caurllent, good, etc, according to mite density as deter~nirled by a total cottnt froni itre 100-leaf sample. R method is outlined, in which, I, ? making use of plotted values, a count of mite-free Icaves only is suflicirnt to allow lie assessmelit of performance in such categories.'Manuscript