By Kimberly Griffin
I was recently in a non-farming related meeting when a colleague passed me a note: I have beetles in my garden, what do I do? With a knowing smile I returned the note with a short list of possibilities: Japanese? Cucumber? Oriental? Potato? She underlined Japanese, and we continued the conversation after the meeting.
For anyone who has either an ornamental or a vegetable garden, the end of June and beginning of July marks the start of Beetle Mania in our region. Last year seemed particularly bad for Japanese beetles, the iridescent, scarab-like bugs about the size of your pointer fingernail. Although I haven’t noticed their full return quite yet, I have noticed their dull brown cousin, the Oriental beetle, emerging from the soil with fury in recent weeks.
I had a moment of panic about a week ago when I witnessed a mass emergence of what I thought were young Japanese beetles from beneath a pepper plant. Not entirely positive of what they were, I didn’t know whether to catch and kill them or to allow them to fulfill their life cycle. I quickly ran to my smart phone, identified the beetle - Oriental beetles - and assessed their threat. Fortunately for those who are growing vegetables, according to some quick research, Oriental beetles are attracted to ornamental plants such as roses and petunias, not human-consumption crops like my peppers. I don’t like killing garden pests unnecessarily, so I let these guys do their thing, though I did keep a watchful eye in case they got hungry enough to alter their tastes.
Japanese beetles are a different story. They are far less discriminating and readily eat the foliage from ornamental and production crops. They "skeletonize" roses, dahlias, berry bushes, basil plants, beans, and more. The answer to my fellow grower’s inquiry on what to do about these guys is pretty straight forward: beetle bags and daily scouting, hunting, picking, and squishing. Some growers are skeptical of beetle bags, which use pheromones to attract the bugs, fearing that they actually draw in more beetles from outside of the garden. I personally like the bags, but they do need to be properly placed according to directions on the box: place them 30 feet away and downwind from the affected crop. Regular hand picking is also effective, though time consuming.
Organic prevention is tough but somewhat possible and certainly gratifying. A Japanese beetle larva is easy to identify and commonly known as a grub: the white, wormy, ugly little beast curled up just below the surface of the soil. Since they spend the winter as subterranean dwellers, hand picking is not as easy as when they are adults. But, as I said, it is gratifying to pop them by hand whenever I find them, knowing that I prevented the growth of a full-blown leaf-muncher. Research has shown that larvae are susceptible to a disease called milky spore, and there are products on the market that can be applied to your lawn and crops as a biological control.
As for the other shelled pests I quickly scrawled in response to my friend’s mid-meeting note, the same scouting, diligence, and scrutiny need to be applied. Fortunately, as their names suggest, these pests tend to stick to a single crop or a family of crops.
Cucumber beetles like the cucurbit family. About the size of a Tic-Tac and bright yellow with black stripes, these little guys are often found feasting on the flowers of summer and winter squash and cucumber plants. They are tiny, fast, and evasive. Scouting for eggs clusters on the underside of leaves is an effective prevention technique.
Colorado Potato beetles (CPBs) love potato plants and especially enjoy eggplants. These guys are nasty, reproducing quickly with voracious larvae. Scouting is key to getting them under control. You can also plant “trap crops” away from main crops to protect your plants. Interplanting cloak plants, such as Cosmo flowers, also helps. If it’s too late for prevention, hand picking is necessary. I have gone so far as to hand pick and collect larvae, blend them in a farm-only blender, then spray the juice back onto plants. The bugs are deterred from the scent of their decaying comrades. Like all foliar sprays, though, this only lasts until it rains.
Of course, this is just a fast and furious list of what could be bugging your garden, skimming the surface of bugs, worms, beetles, and other creepy crawlies. Scout often and get to know your bugs. Some are good, like lady bugs that eat aphids, the spined soldier bug that feasts on CPB larva, and parasitic wasps that lay eggs upon the back of tomato horn worms. Others are bad. Talk to friends and farmers about what they do to protect their crops and flowers. Consider all possible natural remedies before reaching for a chemical pesticide that will eventually end up in our ground water or atmosphere. What kills little organisms can also do significant damage to big ones, too.
Kimberly Griffin is the Farm Manager and Wellness Coordinator at College of St Joseph, working withstaff, faculty, and students to eat, move, and live healthier. She can be reached at: firstname.lastname@example.org