Newspaper man Horace Greeley was overly optimistic in his assessment of the outcome of the battle between human and pest. In the mid 1800s, he insisted that “Man is bigger than the potato bug and he will master it.” I hope Horace wasn’t a betting man.

The potato bug to which he referred is known officially as the Colorado potato beetle, and would prove to be a bigger bother than Mr. Greeley had thought. Even now, it continues to terrorize potato-lovers here at home and abroad. Though native to Mexico and Central America, the potato beetle adapted away from its original taste for native plants, acquiring a liking for domestic potatoes. From its earliest discovery in North America in 1824, it has spread quickly to Europe, North Africa and Asia.

Alas, my interest is not purely intellectual. My potato plants are covered with these potent pests that are calculatingly consuming every potato leaf within their reach. Their appetite is legendary: one single beetle is known to munch 7.5 square inches (the size of a square dinner plate) of leaves during its larval and adult stage! Multiply that by the multitudes of beetles, and an easy estimate is that more than two billion domestic acres and one and a half billion acres of the international potato crops are affected.

If you are not yet cursed with these vermin, you are likely not growing potatoes. They are easy to identify, with 10 brown stripes on their yellow-orange bodies. Find potato beetles on top of each other on the underside of potato plant leaves, or even enjoying your carefully-tended and lovingly-planted eggplant and tomato foliage.

These devious defoliators have easily outwitted us. Andrei Alyokhin, Associate Professor of Applied Entomology at the University of Maine, has much more respect for these small but powerful bugs than Horace Greeley did, calling the potato beetle an “outstanding organism.” He continues, “Over the years, I could not help developing a somewhat grudging respect for the Colorado potato beetle. Humans, with our supposedly superior intelligence, have been trying to defeat this small and rather dumb animal for over 150 years. The weapons ranged from deadly chemicals to plagues of disease and parasites, and from flame throwers to genetically engineered chimeras. Yet, our ten-striped nemesis still represents a major threat to solanaceous crops.”

Many methods have been tried to rid our gardens of these potato pilferers. It is notable that these insects have developed a resistance to all pesticides that have come their way. The beetle’s ability to adapt and conquer is legendary. They became immune to DDT in the 1950s and then went on to overcome all effects from dieldrin, carbonates, chlorinated hydrocarbons, organo-phosphates and many other chemical treatments intended to evict them from the potato fields.

Some success has been had with field rotation, mulch applications, fungal treatments, propane flamers and tractor-mounted vacuum collectors. Likely the easiest ways to save your potatoes are to pick the perpetrators off by hand and dispose of them (read kill), or encourage wild and domestic birds to eat them. Scarlet tanagers, house sparrows, bobwhites, cardinals and rose-breasted grosbeaks all are thought to enjoy a beetle bite.

Potato gardeners have our work cut out for us, since each female adult beetle can lay up to 800 eggs, and the beetle’s life cycle can be repeated three times a growing season. Winter won’t help either, since the beetle’s larvae will cozy up under the ground and wait for next season’s potato crop.

Don’t despair, though. The time may someday arrive when humans’ intelligence proves to be a match for the lowly, persistent potato beetle. Until then, you will find me in the garden, hand picking and squashing each and every one of these pernicious potato predators.

 

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary