Lone star ticks are aggressive and can speedily follow a human target if they detect them. “They will hunt you, they are like a cross between a lentil and a velociraptor,” said Sharon Pitcairn Forsyth, a conservationist who lives in the Washington DC area.

A particular horror is the prospect of brushing up against vegetation containing a massed ball of juvenile lone star ticks, know as a “tick bomb”, that can deliver thousands of tick bites. “They are so tiny you can’t see them but you have to take it seriously or you’ll never get them off you,” said Forsyth, who now carries around a lint roller to remove such clusters.