New insect species reach Estonia every year, entomologist says

Several new insect species reach Estonia every year, while populations of human parasites such as lice and fleas have fallen sharply, ERR reported, citing entomologist Mati Martin.

Martin, an entomologist at the University of Tartu, said on the Vikerraadio programme Huvitaja that Estonia may be home to 24,000 insect species or more. A study conducted more than a decade ago identified about 15,000 species, while comparisons with research in neighbouring countries suggested the higher estimate.

Martin said the expansion of trade allows insects that live on food products to spread quickly with goods. He also noted a sharp increase in tiny black ants known as soil ants, which find stone paving around homes and in other paved areas a suitable habitat.

He said frequent lawn mowing and the presence of dandelions could also favour the ants. In research in his own garden, Martin found ant nests around the roots of nine out of 10 dandelions growing in the lawn.

Insect communities also differ considerably between western and eastern Estonia, Martin said. Different species are active at different times from early spring until almost the arrival of snow, with some continuing to move even beneath the snow.

Overall, insect numbers are declining, Martin said. He added that wasp and hornet populations appeared low this year and that next year might not be favourable for them either.

Insect allergies are a serious problem, Martin said, noting that Estonia has recorded deaths caused by allergic reactions that can develop very quickly. Biting midges can also cause painful bites and remain active throughout the summer and into September.

Insect populations fluctuate in cycles, Martin explained. A normal cycle lasts three or four years, while numbers can rise sharply in the fifth, sixth or seventh year. He attributed the low number of ladybirds seen this year to a normal stage in that cycle, while webbing moths have been relatively numerous.

One of the latest arrivals in Estonia is the sea buckthorn fly, which feeds heavily on sea buckthorn berries. In some places, Martin said, growing sea buckthorn has become pointless because of the insect.

Horseflies are associated with bodies of water and wet areas, where their larvae live in mud or damp soil. Their numbers depend on the availability of suitable habitats, and they are more common near bodies of water.