The chironomid larvae (Diptera: Chironomidae) were found from a tap water in Gunma Prefecture in May, 2003. They were identified as the larvae of Cricotopus yoshimurai Tokunaga and Polypedilum sp. These larvae or adults of the same species were also collected in the water purification plant, the source of the tap water. It suggested that the larvae which live in the water purification plant moved to the tap. This is a case report of a contamination of the chironomid larvae in the tap water, connected with the water purification plant.

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It has already been reported that moth flies, chironomid midges, fungus gnats, gall midges, and small plant-hoppers, as well as small moths, are the dominant room invaders under the operation of the ventilation fan in an adjacent room even on different observation dates. Experiments were conducted under the same conditions to examine the responses of invading insects to an adhesive light trap placed in the room. The intensity of their response to the trap (the number of insects caught on the trap/total number of insects invading the room) was examined for each species or group of insects. The intensity was varied from species (group) to species (group), ranging from 0 to 100%. All individuals of scuttle flies, small plant-hoppers, anthocorid bugs (small hemipteran bugs), and small rove beetles were caught on the trap, whereas few or no individuals of the large moth fly (Clogmia albipunctata), a chironomid midge (Chironomus yoshimatsui), crane-flies, whiteflies were caught on the trap. All or most individuals of the latter species (groups) were flying or staying on the wall or floor in the room, where they were hourly caught with an aspirator. In another series of the present experiments in a room where the ventilation fan was not operated, however, dominant outdoor insect species directly responding to an adhesive light trap in the room through a half-opened window varied among different days. They were manure flies, sand flies, smaller chironomid midges, or ants.

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[in Japanese]

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Feces of the smoky-brown cockroach often present some viscosity in adequate water condition and prone to contaminate foods or medicine packages. We encountered colored-feces contamination by the smoky-brown cockroaches on the surface of food packages. When cockroach food (rice flour) were dyed with various pigments; Japanese fine art colors, water color paints, carbon, black-ink, sepia, soybean souse, ketchup, colored food additives, etc., the color of feces was assimilated with each of dyed foods, with a few exceptions (e.g., soybean souse and ketchup). This suggests that feces of various colors should contaminate packages of foods or medicines.

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[in Japanese]

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