A carbon dioxide trap for prolonged sampling of Ixodes ricinus L. populations.

A carbon dioxide trap designed to capture Ixodes ricinus over periods of up to 7 days is described. The trap compared favourably with blanket dragging and flagging in areas of high tick density, particularly on rough ground and for adult ticks; it was also surprisingly efficient for larvae. Ticks appeared to be captured throughout the 7-day trapping period. The maximum attraction distance recorded for adult female ticks was 3.5 m and for nymphs 1.0 m. Trapping rates were influenced by air temperature.