Tag Archives: invasive plants

Army of 500

The Bald Range is an open, grassy mountainside tucked in among the pine forests of the central Okanagan. Elegant bunchgrasses and hardy balsamroots abound. Native bees and other insects attend the flowers while overhead, solitary raptors work the thermals. The Bald Range is a landscape well suited to epiphany, but its humble beauty has been marred. Historical overgrazing, fire suppression and all-terrain vehicles have each left their legacy of damage.

Part of that legacy is a truly spectacular infestation of a noxious alien weed known as Saint Johnswort, on a portion of the Range. This European weed is common in many parts of BC’s southern Interior and the Lower Mainland, but the populations are typically small and scattered. This is due to a highly successful biological control insect known as Chrysolina. This fat, glossy beetle was purposefully introduced in BC in the early 1950’s and it became a very successful immigrant, spreading its progeny throughout the southern half of the Province. The beauty of Chrysolina is its voracious appetite for Saint Johnswort, and its total disdain for any other plant.

As a longtime volunteer and occasional consultant on the Bear Creek Bald Range (one must be specific—BC has several Bald Ranges), I was acutely conscious of its Saint Johnswort infestation, which in places made up 90 percent of the vegetation, displacing bunchgrass, balsamroot and pretty much everything else. But oddly, there were no Chrysolina attackers. This particular beetle is easy to spot, due to its iridescent black body, but several close inspections of the Bald Range during peak season never revealed a single beetle. This was strange, since the beetle is considered well established by Provincial authorities, and can be found everywhere that its host plant is found.

So I added this observation to my list of Bald Range questions and curiosities, and carried on. But by the summer of 2015 it was obvious to our cadre of Bald Range volunteers that the Saint Johnswort infestation was spreading, and spreading rapidly. Saint Johnswort is a well-known herbal remedy for depression, and I figured we now had enough biomass to cheer up several provinces and territories.

I put in a call to Catherine Macrae, an invasive plant specialist with the Ministry of Forests in Nelson, BC, to see if there was any chance of getting a few beetles. She told me the Chrysolina was experiencing one of its periodic down cycles, and few were available for capture and re-release. But she promised to keep my request in mind. Then in the spring of 2016, Catherine’s technicians found a burgeoning population near Nelson, and I got an urgent notice that 500 beetles were coming via express bus to my home town of Summerland.

I arrived at the bus station promptly at the appointed arrival time and—no bugs. Frantic and knowing the beetles experience high mortality from shipping delays, I called Catherine. She gave me the tracking number and I contacted every depot on the various bus routes between Nelson and Summerland, the destination. No luck. “In transit” was the standard unhelpful answer. The Bald Range’s chances for a Chrysolina rescue were fading fast. I waited several anxious hours, made the round of phone calls again, and found the package was sitting at the bus station in Kelowna. The warehouse person reminded me that it was Saturday morning, they were closing in 45 minutes, and would re-open again on Monday. In turn, I reminded myself that it was over an hour’s drive from my house to the Kelowna bus station.

Pedal to the metal on Highway 97, my ancient Suzuki smoking from overexertion, I had visions of beetles dying slow and excruciating deaths in the airless, weedless Kelowna bus warehouse.  But somehow the gods of Kelowna’s endless out-of-phase traffic lights smiled on me, and I sailed right through to the north end bus station, where the package awaited. The warehouse person was not at all pleased to hear that the box was full of insects, and he very reluctantly loaned me a razor knife to open it with. And there, carefully packed in five vented plastic containers, nestled in Styrofoam and sharing a cold pack, were five hundred live, active insects. I thanked the apprehensive warehouse man profusely, and made a beeline, or rather a beetleline, for the Bald Range.

To get to the Bald Range, one drives twelve kilometers up the supremely dusty and washboardy Bear Creek road, a kilometer up a spur road, and finishing with a steep ten minute hike to get on to the Bald Range itself. I had transferred the bug containers from the box into my pack, and now I began to worry that my black backpack was acting as an unintentional solar oven, and the bugs would overheat and die on the very last leg of their epic journey. So I did the hike in record time. Arriving at the middle of the Saint Johnswort infestation, I was relieved to see the bugs were still active in their containers. Now I faced a dilemma that I hadn’t thought of before—where was the best place to put them—a dry spot, a wet spot, a spot with young plants, or mature plants? In the end I decided on five separate locations, each slightly different, and I marked them with my trusty GPS for future reference.


I have been on the margins of biological control for many years, but never actually participated in an insect release. So gently emptying these bugs from their containers was the culmination of a very long personal and ecological loop. Now I was embracing the full contradiction of biocontrol—introducing a new alien species to control an existing alien species. But these are exactly the kinds of delicious paradoxes that keep drawing me back to ecology.

My Chrysolina release was one of the handful of acts of random beauty one gets to be a part of in a lifetime. This delivered beetle population may, in their insect wisdom, take to the Bald Range, or they may reject it and die. After all, they were many kilometers and generations removed from their home country of England. One very plausible outcome of the release: the beetles will be successful, but the niche that Saint Johnswort formerly occupied gets filled by a new alien species from our foul and burgeoning cornucopia of invasive weeds.

Most of my tiny iridescent army of 500 came out of their containers easily, but there were a few which I had to coax out on to my finger, and then place on to a carefully chosen Saint Johnswort leaf. Those last few holdouts seemed genuinely grateful, and so was I.