A series of lab experiments with ticks (collected by flagging in the natural biotopes in North-Western Russia) was carried out in order to study tick reaction to attractants imitating the smell of a potential host. All the ticks that showed either positive or negative reactions to attractants in the experiment were individually PCR-tested for B. burgdorferi s.l DNA.

The percent of Borrelia - positive specimen among hungry active adult I. ricinus and I. persulcatus ticks was higher than that among hungry passive ones. The discovered infection of I. persulcatus females by B. burgdorferi s. l. was 56% from which 67% were active and 36% were passive ticks. Total infection of adult ticks was 45% (61% active, 24% passive ticks). Infection of I. ricinus females was 60%, 69% in active individuals and 48% in passive, total infection of adult ticks was 56% (70% in active, 43% in passive). Synthetic kyromonas (attractant) composed of 1-octen-3-ol and a mixture of ethyl myristate-methyl salicylate (1:1), simulated the odour of the host in the experiment, attracted up to 70% of adults of I. ricinus and up to 80% of I. persulcatus. It can be assumed that this percent of adult ticks reflect an overall number of individuals searching for a hosts during the season of activity in natural biotopes.