Category Archives: Pests

No harlequin beetles in sight on kale photographed on Aug. 28, 2014

A couple of weeks ago, I warned that a harlequin beetle invasion was imminent. Their favored food, kale, was doomed, I said. And I had photos to prove it. Yet in a recent inspection of the indefatigable kale crop at the Garden RUN Community Garden, nary a harlequin beetle could be found. Katie Brownell, who manages Wyck Farm, was bracing for the expected invasion of beetles that had devastated her cole crops last August. She, too, was surprised that they never came. The bitter-cold spells this past winter must have done them in, she said. Or maybe they just didn’t like the mild summer weather that most of us here in Philadelphia loved. Whatever the case. we Philly gardeners are glad they stayed away.

UPDATE - Sept. 24 Oops. They’re back, after all. But not as many as last year. They’re swarming the kale in some plots, but not others, in contrast with last year, when everything withered before their onslaught. And they haven’t yet discovered the kale seedlings I just planted amidst lettuce and spinach. I’m hoping a row cover will give them a growth spurt in the warning warmth and will keep that late-arriving harlequin beetles at bay until cold weather knocks them out.

Harlequin bugs on Sept. 24, 2014

Kale, lettuce and spinach, going under wraps, Sept 24, 2014

Harlequin bugs plotting conquest of Tuscan Kale crop, Aug. 16, 2014

This time last year, our community garden was overrun with a downright Biblical swarm of harlequin cabbage bugs. They destroyed everyone’s kale before moving on to other cole crops. This year, the bugs have been very few and far between – until now.

I spotted several lone bugs on Aug. 15. On the 16^th, I saw, ominously, a cluster of four.

Jill, our Garden RUN garden’s leader, sent us an email on Aug. 11 raising an alarm about “beetles, and I’m not talking Fab 4.” She warned, “Due to the cold winter, the beetles have been way late in appearing, but they are coming. Check under leaves for the double row of gray barrels (about 12-16 eggs), each the size of a pin head and drown them. Smush the adults.”

According to the Wikipedia entry for the pest, it is also known as calico bug, fire bug or harlequin bug, and is a member of the black stinkbug family. It ranges from the tropics to the warmer parts of North America, and according to Wikipedia, it feasts on cabbage and related crops such as broccoli and also has a taste for radishes.

The ones that visit our garden in Roxborough have exceptionally discriminating palate, judging from my observations. They have an unmistakable preference for kale, especially the Tuscan variety. Last year, they especially loved the nice crop of baby Russian kale that was just leafing out when they arrived. This year, everyone I’ve seen so far as been on Tuscan kale. The earlier arrivers apparently have no interest in the beautiful big Russian kale, or frilly green kale, or purple cabbage sharing the same plot.

So, how do you deal with harlequin cabbage bugs? Here’s what Wikipedia has to say:

“Organic control involves hand-picking the insects off the plants (they can be dropped into soapy water to drown them) and being especially careful to remove and destroy all the eggs, which are black-and-white striped, laid in clutches of twelve.” The entry goes on the say that they are non-toxic “and can be safely fed to poultry or pet reptiles or amphibians.”

In my plot at the Garden RUN community garden in Roxborough, my cucumbers were vigorously climbing a trellis one week. The next week, they went limp and died. When I told my garden neighbor, Chuck, about my cucumbers’ tragic demise, he said that he, too, had lost cucumbers as well as squash in similar, sudden fashion. He suspected that a worm of some sort had burrowed into the vines.

Dead cucumber, photographed on July 21, 2014

At about the same time, all of my basil plants began to turn yellow then black around the edges. Looking around the garden, I noticed that everyone’s basil had suffered the same fate. Meanwhile, the basil plants in pots in my backyard are as healthy as can be.

Last year in August, our entire community garden was swarmed with what must have been millions of harlequin beetles. Everyones’ kale and other cole crops were wiped out. In my backyard garden, nary a harlequin beetle showed up.

Diseased basil, photographed on July 21, 2014

All of which begs the question, are community gardens unusually susceptible to pests and diseases? Or does it just seem that way? I asked an expert, Sally McCabe, who heads a program of the Pennsylvania Horticultural Society called Garden Tenders, which trains people wanting to start community gardens. This is her emailed response.

1) I think it’s more an issue of perception than of actual percentages. Willie Sutton said he robbed banks “because that’s where the money is.” A greater concentration of vegetables yields more bugs.

2) If you’re gardening in both your backyard and a community garden, more times than not you have less sun in your yard than in the cg. More sun in summer leads to more stress, therefore more bugs & disease.

3) Soil fertility is key. Where is the soil quality better? Yard or garden? Less soil fertility yields more bugs & disease.

4) Where is access to water better? Better access yields less stressed plants, so less bugs & disease.

5) Are you an observant gardener? If so, you’ll have less b & d. Garden alone, and you’ll have a consistent, probably healthy garden. Garden next to somebody who doesn’t pay attention to their plot, and their b&d will get out of control, spilling over into yours.

6) More diversity yields less b&d. Is there more diversity in the home garden?

Luck also must have something to do with it. Sally said that last year, the CSA farm where she is a member lost all of its basil to mildew by midseason, but the basil in her yard and in her community garden plot did fine. Go figure.