A CIRCADIAN-RHYTHM OF LOCOMOTOR-ACTIVITY IN NEWLY EMERGED CERATOPHYLLUS-SCIURORUM

Circadian rhythm in newly emerged individuals of the Red Squirrel (Scu irus vulgaris) flea C.s, sciurorum was studied in a constant environme nt, using an insect activity monitor. Trials were run over 7 days usin g two start times (08.00 and 17.00 hours). The results show that, rega rdless of start time, the fleas display a 24h activity rhythm. The pre sence of a rhythm under constant conditions gives a strong indication that C.s.sciurorum has a self-sustaining clock which is started by dis turbance and is most likely to be linked to host activity patterns.