The trees are encased with cobwebs

Swarms of hungry caterpillars have defoliated trees in Russia's second city, St Petersburg, covering them with cobwebs and transforming public parks into scenes likened by Russia TV to sets from a horror film.

"The situation is critical," Tatyana Dorofeyeva, an insects specialist at the parks' protection department said. She said that the authorities' countermeasures taken to date were thought to be no more than 50% effective.

The bird-cherry ermine moth caterpillars (Yponomeuta evonymella) strip the trees of leaves and then cover what's left with a cobweb-like substance from the roots up.

They're still multiplying Russia TV correspondent

"Right now the caterpillars are multiplying at an incredible rate and producing their cobwebs on an industrial scale," the TV reported.

Parks' department staff are said to be working flat-out to contain the outbreak.

"The caterpillars are not poisonous but in these quantities they could aggravate allergic reactions, biologists say. Trees are inspected after being sprayed. The results are not reassuring. They're still multiplying," a correspondent said.

"The city had no idea that it was under threat from such an invasion," Galina Tyullina, head of the parks' protection department, said. "If the situation had been monitored in good time and arrangements made for treatment to be carried out, we could have gone out spraying in early May and headed this off in advance."

The city's inhabitants are already bracing themselves, first for the airborne invasion of bird-cherry ermine moths when the pupae hatch in four weeks' time: and then for next year's expected sequel - dubbed by the TV "Invasion of the Caterpillars 2".

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