Western tent caterpillars were already devouring a gorgeous deodara earlier this month in Diamond Point. (Andrew May)

Western tent caterpillars were already devouring a gorgeous deodara earlier this month in Diamond Point. (Andrew May)

A GROWING CONCERN: Attack of the killer tent caterpillars

They’re baaack.

I think invoking an infamous horror movie is so apropos because these voracious demons not only terrorize your trees but leave an eerie, disgusting, leaf-stripped plant loaded with abandoned, feces-filled, discarded bags that horrify anyone’s sense of aesthetics.

Of course, I could only be talking about the recurring scourge known as the Western tent caterpillar.

Unfortunately, these little monsters were seen quite heavily in the trees last year, working their way up U.S. Highway 101 from the Hood Canal.

I knew this was going to be bad news for us here on the Olympic Peninsula this year, and sure enough, two weeks ago I saw them on a deodara tree out at Diamond Point.

Then just last week, very good friends in Port Angeles had a large Western red cedar with these little beasts already devouring the “dead tree walking.”

Making matters even worse, there are at least six current recognized sub-species and they prey on various shrubbery.

This is why I saw them first on these two conifers, even though we normally associate them menacing alder, maples and other deciduous trees.

Regardless, they are gregarious and spend a good deal of their time with their colonies, constructing ever-expanding silken “tents.”

What makes them manageable is the fact that the tent caterpillars are univoltine, going through only one reproduction cycle a year.

In late summer, adult moths lay eggs on the sunny side of trees, emerging as hungry little foliage-devouring henchmen in early spring.

Fortunately, although they lay waste to the host plant, their damage is rarely, if ever, fatal.

But again, the impact to the plant seems horrific.

So what is the gardener to do? I doubt one can just grab a pitchfork or a torch and confront these abominations.

First, on the sunny side of smaller shrubs, trees and bushes, look for the little half-inch-long gray, bubbly Styrofoam-looking formations and squash them.

Do that now.

Next, and most importantly, be vigilant.

Look for them early and often.

They eat their weight several times over every day. Got that? Several times their weight a day, so get these barbarians as soon as possible.

One of the easiest ways is to cut them out of the plant when you see the small tent beginning to materialize.

Always use a proper pruning technique when “chopping out” their lair.

Next, and especially for taller, hard or impossible areas to reach — spray them.

A “host specific” treatment is to spray them with BTK (bacillus thuringiensis kurstaki), a biological control.

They also are controlled naturally by birds and a parasitical wasp that lays eggs in the body of the caterpillar.

In a classical “predator/prey” cycle, these two nemeses bounce up and down so severe infestations occur every 6 to 8 years.

So please, please, please protect your plants from the horror of being devoured alive and seek out and destroy these demons.

Also, in the same vein, get after slugs, mice and shot-weed because spring has sprung and it’s a race against petulance.

Next week: April. Woo hoo!

________

Andrew May is an ornamental horticulturist who dreams of having Clallam and Jefferson counties nationally recognized as “Flower Peninsula USA.” Send him questions c/o Peninsula Daily News, P.O. Box 1330, Port Angeles, WA 98362, or email news@peninsuladailynews.com (subject line: Andrew May).

More in Life

CutlIne: What beautiful long ears and adorable eyes he has! Meet Rio,  a mammoth donkey who grew to 16’2 hands tall.
HORSEPLAY: Want a donkey? A beginners guide to donkey care

GOT THE URGE to bring home a cute, adorable miniature donkey? I’ve… Continue reading

The Rev. Pam Douglas-Smith.
Unity in Port Townsend planning for Sunday services

The Rev. Pam Douglas-Smith will present “Heart Centeredness” at… Continue reading

A GROWING CONCERN: Good habits build character for your garden

LET’S RECAP WHERE we are so far this year. I am back… Continue reading

“Against all Odds: Abandonment to Olympian, A Tribute to Joe Rantz” by Catherine Bilyard is one of 41 quilts on display in Sequim Museum & Arts through the end of March as part of the “Inspiration/Exploration” exhibit. (Matthew Nash/Olympic Peninsula News Group)
Joe Rantz quilt highlighted at Sequim museum

Tribute among 41 pieces in show

Sunday program set for OUUF

Joseph Bednarik will present “Sex and the Dictionary” at… Continue reading

ISSUES OF FAITH: Cut away what holds growth back

IT’S FEBRUARY AND time to begin pruning the vineyards in Eastern Washington… Continue reading

Steve Mullensky/for Peninsula Daily News

A perch on the bowsprit affords these spectators a wide open view of competing boats in a previous year's regatta on Port Townsend Bay.
Shipwrights’ Regatta set for Saturday

The sailboat racing season opens Saturday with the Port… Continue reading

Mason bee lecture scheduled

Carrie Morlag will discuss raising mason bees at 10 a.m.… Continue reading

Work to learn in Sequim Saturday

John Hassel will demonstrate how to prune roses at 1… Continue reading

Geology lecture set Saturday

Brian Sherrod will present “High-resolution dating of a multi-fault… Continue reading

Wool spinning demonstration set

Dean Hyden will demonstrate the use of a spinning… Continue reading

Red, Set, Go! Heart Luncheon set for Friday

The Olympic Medical Center Foundation will host the 16th-annual… Continue reading