Tent caterpillars have been sighted in forested areas in Nova Scotia more than usual this spring.  They can strip trees of every trace of green while they build the spider-silk-like tents for which they've been named.

They look like a menace, but they don't pose the same threat some other species do to our Maritime forests.

Just their appearance can be repelling. What's worse, when they move into a group of deciduous trees, they are voracious and chew up anything that looks remotely green. Then they build these ominous-looking tents.

Numbers peak at the end of a 10-to-12-year cycle, depending on conditions and it's the worst anyone has seen in years.

“It all depends on what our spring is like, and whether there's much winter kill, and what the conditions are like now,” says Andrew Hebda, a curator of zoology with the Nova Scotia Museum of Natural History. “They like the moist conditions, nice fresh vegetation.”

In another week or so, they'll change.

“There's only one generation per year, so they'll come in, they'll be feeding on those fresh leaves, they'll go through those transformations into adults, and then, as adults, they'll go and lay their eggs for next year's crop,” says Hebda.

It can be pretty scary when you see a group of trees stripped of all their leaves by tent caterpillars, but it's not as big a problem as you might think.

Fruit trees have been bitten by frost this year, but not by caterpillars.

“The leaves are quite thick, quite waxy, so they tend to be well protected,” said Hebda.

Forestry experts say they don't represent a danger to our tree species...   

Jim Rudderham, a forest protection manager with the Nova Scotia Department of Natural Resources, says they’re not a concern for forest stands.

“They're more of a nuisance for the look of the ornamental trees on your front lawns,” Rudderham said.

The moths have their buffet early enough in the season that trees that are affected will have time to recover.

“They're almost done their feeding time, and the trees will re-flush their leaves and be fine after that,” Rudderham said.

Even the adult moths won't be around for long. They'll mate, lay eggs, and then die, likely before the first of July.

With files from CTV Atlantic’s Ron Shaw.