THE PERIODICITY OF FEMALE CALLING IN THE BLUEBERRY SPANWORM ITAME ARGILLACEARIA PACK. (LEPIDOPTERA: GEOMETRIDAE)

Abstract

AbstractThe calling of female blueberry spanworms occurs primarily during the first few hours of the photophase under controlled laboratory and field conditions. Peak calling occurred 2 h after lights-on at laboratory test temperatures of 20,15, and 10 °C under a light:dark regime of 16:8; duration of calling was prolonged at 10 °C. Under continuous scotophase, female calling activity free-runs at a natural periodicity of ca. 27 h. However, under continuous photophase the circadian rhythm is damped to a low level of activity but maintains a ca.24-h periodicity.