Where did viburnum leaf beetle come from?

The Viburnum Leaf Beetle: A Tiny Traveler with a Big Appetite

So, the viburnum leaf beetle, or VLB as some of us call it – Pyrrhalta viburni if you want to get all scientific – is this little bugger that’s causing quite a stir among Viburnum lovers like myself. It’s an invasive pest, meaning it doesn’t belong here, and it’s got a real taste for our beloved viburnums. Where did this troublemaker come from? Let’s take a look.

From Eurasia with a Vengeance

Turns out, VLB is originally from Eurasia – Europe and Asia, to be exact. It’s been munching on viburnums over there for who knows how long. But somehow, it made its way across the pond. The first time anyone officially noticed it in North America was back in 1947, in Ontario, Canada. But get this: some folks found specimens way back in 1924 in Nova Scotia! The mystery is, were those just early scouts, or did a population get established that early? We don’t really know. What we do know is that by the 70s, they were definitely setting up shop. How it got here in the first place is still a bit of a head-scratcher. The most likely story? It hitched a ride on some nursery plants imported from Europe.

Landing in the USA

Fast forward a few years, and BAM! In 1994, the viburnum leaf beetle showed up in Maine. And it didn’t take long to spread. By ’96, it was wreaking havoc in New York State, especially along Lake Ontario, where the native arrowwood viburnums were getting absolutely hammered by the larvae. I remember seeing pictures at the time – it was devastating.

Coast to Coast (Almost)

Now, these beetles have spread even further. By 2015, they’d pretty much made themselves at home all over the place. We’re talking British Columbia in Canada, and a whole bunch of states, from Connecticut to Wisconsin. And as of 2021, they’ve been spotted in a dozen counties in Wisconsin alone! The good news? They need a good, long cold snap to hatch, so maybe they won’t head too far south.

The Damage They Do

These beetles are picky eaters. Both the larvae and the grown-ups only eat Viburnum plants. And they can do some serious damage. The larvae are like tiny leaf-skeletonizing machines, leaving behind nothing but the veins. The adults aren’t much better; they chew these ugly oblong holes in the leaves. If you get a bad infestation, your plant can lose all its leaves. And if that happens year after year, the viburnum can get so weak it just gives up the ghost. It’s heartbreaking to watch.

Fighting Back

So, what can you do about these pesky invaders? Well, here are a few tricks I’ve learned over the years:

• Pruning is your friend: Get rid of any twigs with egg masses on them in late winter or early spring. It’s like nipping the problem in the bud (pun intended!).
• Bring out the big guns (insecticides): If you’ve got a serious infestation, you might need to resort to insecticides. Hit ’em when the larvae are small. Systemic stuff can work too.
• Choose wisely (resistant varieties): Some viburnums are tougher than others. Plant those!
• Keep an eye out (monitoring): Check your plants regularly for eggs and larvae. The sooner you spot them, the easier they are to control.

Sure, you might see a ladybug or lacewing chowing down on a VLB larva now and then, but don’t count on them to solve the problem. They just can’t keep up with a full-blown infestation.

The viburnum leaf beetle’s story is a reminder that our world is more connected than ever, and that sometimes, those connections can bring unwanted guests. By understanding where this beetle came from, how it spreads, and what damage it can do, we can all do our part to protect our viburnums and keep our gardens thriving.