Effects of feeding on the circadian rhythm of Ceratophyllus s. sciurorum (Siphonaptera : Ceratophyllidae)

Circadian rhythm in newly emerged blood-fed individuals of the flea Ceratop hyllus s. sciurorum was studied in a constant environment, using an insect activity monitor. The results of trials run continuously over seven days co nfirmed the finding that C. s. sciurorum has a self-sustaining clock. Stati stical tests confirm that feeding weakens the rhythm but does not eliminate it. There was a significant difference in the mean activity between the fe d and unfed fleas, reflecting the difference in the number of hours over wh ich this activity took place. A possible commercial application for the mon itor and also for the method of analysis is discussed.