A dear friend was telling us that her son has potato bugs after a clear crop for several years. I know we all have that sense of disappointment when we spot the first of those little striped visitors to the garden! The Colorado potato beetle definitely is a garden pest. Did you know that an adult potato bug can lay thirty eggs a day? The eggs are little orange ovals, hiding on the underside of the potato leaves. The eggs will hatch anywhere from four to fifteen days, depending on the weather.
And once they hatch, they begin nibbling on our potato plants. What a disappointment! It doesn’t take long for them to do a lot of damage, and if we gardeners aren’t diligent the plant can quickly be reduced to the spindly sight of plant ribs minus leaves!
The eggs hatch out in four stages, called instars, which take about two weeks to complete. But the final stage is really just the beginning of trouble for our potato plants, because the pupa burrows into the soil for a few more days till it comes out as a potato bug in about another week. If the weather is starting to turn, the larva goes into hibernation and waits for next spring. Because a female can lay up to 900 eggs in her lifetime, this pest can bring real devastation. And because potato bugs can fly, they can move around till they see a fresh, pristine potato plant that looks like a salad buffet to them!
So what to do if the little invaders have invaded our potatoes? If we don’t have a huge potato patch, we can try to hand pick the potato bugs and the eggs. This is a tedious task, yes, but it is organic and we can definitely feel like we are in control of the process. Natural predators like ladybugs are also most beneficial, because they eat the eggs from the leaves.
If you want to use a product, diotomaceous earth is environmentally friendly. Diotomaceous earth is a natural product made from the fossilized remains of tiny aquatic creatures called diatoms. DE looks like powder but if we saw it under a microscope we’d see that it is actually made of sharp fragments that damage the soft bodies of bugs. There is no harm to the plants or to bird or pets. If we decided to use this product, we would sprinkle it on the plants and around the base of the plant.
I have also heard members of the Hort society talk about neem oil. When used for potato bugs, the oil coats the eggs and stops the, from hatching, and it also makes the potato leaves taste bad to the bugs. That sounds like it would make them move on!
Another effective and organic answer is to grow different crops in the spot where the infested potatoes were last year, plants that don’t belong to the nightshade family. It’s like crop rotation. So if we wanted to try that, we should move the potatoes to another part of our gardens, and avoid planting things like tomatoes, peppers, eggplant, or flowers like petunias or nicotiana.
The Hort Society had a Zoom meeting last week; thank you very much to John, our webmaster, for setting the meetings up for us all year, your effort is very much appreciated! And thank you to the great gardeners who showed spirit and took part, your participation was valued. We’ll see what happens next! Time marches on! We just had the longest day of the year this past Sunday. Visit the Yorkton and District Horticultural Society at www.yorktonhort.ca and see what’s new. Thank you to our friends at YTW for great work! Have a good week and be sure to wear a hat!
