Diel activity of the adult Argentine stem weevil

Abstract

Feeding intensity of adult Listronotus bonariensis (Kuschel) in the laboratory increased linearly with temperature, between approximate lower and upper thresholds of 5°C and 42°C. Diel fluctuations in abundance, as indicated by sweep netting, was used as a measure of field activity. During summer, activity was mainly nocturnal, with a peak after sunset, but some activity occurred during overcast and bright sunny days. Summer weevil activity during darkness was related to temperature. In winter, activity occurred predominantly during daylight. Day and night activity was related to temperature; on many winter nights the temperature was below the lower threshold for activity.

Keywords:

• Listronotus bonariensis
• Argentine stem weevil
• diel activity
• temperature
• pasture
• activity threshold