Kew Gardens is reassuring visitors after a potentially deadly exotic moth was discovered at the centre.
Climate change may have pushed the unwelcome visitors northwards
Nests built by the Oak Processionary Moth have been found at the Royal Botanical Gardens in west London.
The creatures can set off severe allergic reactions and irritate the lungs, eyes and skin as well as stripping leaves from oak trees.
Kew said there was "absolutely no danger" at present after blowtorches were used to destroy the nests.
Officials also used hairspray to stick together the caterpillar hairs, which contain toxins.
But experts have been unable to rule out the possibility that eggs laid elsewhere could hatch in the spring sparking a fresh infestation.
The moth normally lives in southern Europe but has spread northward as a possible result of climate change. Reaction to hairs
Its toxins have led to the closure of forests in other parts of Europe at certain parts of the year - usually late April to July.
While people in other parts of Europe are reported to have died from over-reactions to its hairs, Kew said that descriptions of it as a "killer moth" were overblown.
It said that deaths from reaction to the caterpillar hairs were comparable to those from bee or wasp stings.
Eggs laid on imported trees planted at a housing estate in west London are thought to have spread the moth to Kew earlier this year.
The species was also reported to have been spotted at a nearby graveyard and close to the A40 road.