Tests for Audible and Ultrasonic Sound Production by Stored-Product Insects1

Abstract

Ten species of stored-product insects were studied for the production of nonincidental sounds. Eight species confused flour beetle, Tribolium confusum Jacquelin duVal; merchant grain beetle, Oryzaephitus mercator (Fauvel); granary weevil, Sitophilus granaries (L.); flat grain beetle, Cryptolestes pusillus (Schonherr); furniture carpet beetle, Anthrenus flavipes LeConte; Trogoderma glabrum (Herbst); tobacco moth, Ephestia elutella (Hubner); and almond moth, Cadra cautella (Walker)-were monitored both in whole colonies over a 24-hour period and individually (adults, pupae, and last or penultimate instar larvae) under conditions of stress. Two spider beetles, Mezium americanum Laporte and Gibbium psylloides (Czempinski), were monitored under conditions of stress. Both audible (1–14.5 kilocycles per second) and ultrasonic (15–60 kilocycles per second) ranges were monitored. A method of determining the minimum discernible signal of a microphone by electronic means is described. No stridulatory or protest (stress) sounds were heard.