Pest Insects of Confections in Miyagi Prefecture, with Special Reference to Ecology of the Indian Meal Moth, Plodia interpunctella I

Abstract

During the period of 1968 and 1969, insect pest of the confection was investigated in Miyagi Prefecture.
Almost all the damages found out by the consumers' complaints about worm-eaten confectioneries as well as the damaged ones detected by our observations in the marketing process, were caused by larvae of the Indian meal moth, Plodia interpunctella. The number of damages above-mentioned was conspicuous with the chocolate group, especially chocolate with nuts, solid milk chocolate being the next. The damages among other confectioners; those with nuts or beans, such as sugar-coated nuts or beans, were remarkable.
The rest, the Saw-toothed grain beetle, Oryzaephilus surinamensis, and the Japanese white-marked spider beetle, Ptinus japonicus, ate solid milk chocolate.
In addition to this, the varied carpet beetle, Anthrenus verbasci, was found in the bait trap using biscuits; and the Meal snout moth, Pyralis farinalis, the European grain moth, Nemapogon granella, the Japanese grain moth, Aphomia gularis, the Rice weevil, Sitophilus oryzae, and the Azuki bean weevil, Callosobruchus chinensis, were collected in our general survey.
Plodia's distribution proved to be wide in the Prefecture owing to the consumers' complaints and to the bait trap method (using solid milk chocolate, biscuits, caramels with peanuts). And the insect found in all stores where we set the trap: candy stores, general food stores (inclusing super-markets), and small-sized general stores dealing confections; and in every warehouse of wholesalers. Besides, Plodia was often found in onsumers' houses. Thus, the damage by this insect may take place everywhere.