Abstract
To evaluate the ability of hatching larvae of the Indian-meal moth, Plodia interpunctella Hubner, to reach their food, open food containers (3cm diameter, 5cm height) and closed ones with a pinhole of 0.495mm diameter in each cap were exposed to them. When the food containers were 10cm distant from eggs, 100% hatching larvae reached the food and 31% of the invading larvae were found in the closed containers (with a pinhole). When the distance was 38cm, 65% larvae reached the food, and among them 79% and 21% were found in the open and closed containers (with a pinhole), respectively. Two kinds of cap films, polyethylene and vinylidene chloride polymer films, gave similar numbers of invading larvae when each had a pinhole. The results indicate that even first instar larvae would contaminate food containers 38cm distant by invading them through pinholes.
