In order to survey what insects and mites would be injurious to milk powder the author set traps in Sapporo (5 houses), Yakumo (3), Nakashibetsu (3), Ashyroro (3) and Taiki (3) for a year from May, 1974 to the April, 1975.
In each trap milk powder was used as the bait, and the traps was placed for 30 days every month in each house. In addition to this, trappings were carried out for 20 days in all 5 houses in Sapporo and one house of each of the other 4 towns. So the total numbers of traps used in this survey were 312.
In 27 traps in 108 traps of the 10-days series (25%) and 51 in 204 traps of the 30-days series (20%) some small insects or mites were detected by Wildman's trapping method.
They belonged to 7 species of insects, to 9 species of small mites, to 2 species of Arachnida and to 1 species of Isopoda.
From the author's own data of the survey in 1968, 7 species of insects were found in the same traps in addition to the above species, so in Hokkaido a total of 26 species of Arthropoda have been reported by this trapping method.
Liposcelis bostrychophilus was found in 24 traps (7.7%) and is thought to be the most important insect. Among small mites
Tyrophagus putrescentiae was the most significant and was found in 34 traps (10.9%).
抄録全体を表示