SEASONAL ACTIVITIES OF THE PIGEON TICK ARGAS-REFLEXUS (ACARI, ARGASIDAE) IN BERLIN, GERMANY

The seasonal activities of the European pigeon tick, Argas reflexus, i n Berlin were investigated (a) by trapping locomotory active ticks and (b) by determining the occurrence of tick-invasions into human habita tions. Tick trapping was carried out in two tick-infested attics in 19 88. Pigeons were available for ticks in one of the attics only, while a previously existing bird colony was expelled from the other. Ticks w ere trapped by means of smooth V-shaped metal gutters cemented to the attic walls. Trapped nymphal and adult ticks were marked and released into cracks of the attic wall inside the rectangular traps in two-week -intervals. During the one-year-study a total of 2081 ticks was trappe d, 83% of which were larvae. 10% nymphs, 4% females and 3% males. Only 4.4% of the 366 ticks marked were recaptured. There is strong evidenc e that locomotor activities of A. reflexus were restricted to host-see king and returning to a resting-site after a blood meal. Activities of all postembryonic stages peaked from March through early June. irresp ective of whether or not hosts were available to the ticks. The immatu re stages displayed another peak of activity in late summer/autumn. A total of 51 cases of A. reflexus-infested buildings was reported from the public to public-health offices in Berlin from April 1989 to March 1993. 45 of which represented tick invasions into human habitations. About 60% of them occurred in spring, thus largely confirming the resu lts of seasonal trapping.