Economic Status of the Japanese Beetle in 1932

Abstract

In 1932the Japanese beetle (Popillia japonica) probably caused greater destruction of fruit and produce crops than in any year since its discovery in 1916. A larger number of classified nurseries disclosed infestations than during 1931. Traps distributed in cities and towns outside known infested territory resulted in discovery of a large number of first record infestations at points more remote from the densely infested zone than any heretofore found infested. This does not necessarily indicate a greater spread of the insect in 1932 than in any previous year, but demonstrates that scouting with traps is more efficient than visual scouting by temporarily employed scouts. Survey of southern New Jersey, southeastern Pennsylvania and northern Delaware sections most heavily infested by the beetle disclosed that from 75 to 100 per cent defoliation of preferred food plants took place over an area of 1,647 square miles, that foliage damage of from 50 to 75 per cent was evident in 1,378 square miles, and that evidence of at least 25 per cent foliage injury was observed over an additional area of 1,353 square miles.