Centipedes, Millipedes and Squash Vine Borers

Adult Squash Vine Borer, Photo by Jeff Hahn

We got a question today from a customer who says centipedes are damaging the roots of his squash plants. "I noticed a bunch (maybe 50) centipedes on the roots of my squash plants."

First of all, they are probably millipedes. Centipedes (which have one set of legs per segment) would be eating other insects. Millipedes (two sets of legs per segment) are sometimes found in large numbers in moist garden soil that contains a lot of organic matter because they feed mainly on decomposing organic matter. Sometimes they will damage young seedlings, but usually the problem starts otherwise; and the millipedes are eating the damaged, rotting stems and roots. For instance, if your soil is staying too wet or if you’re watering late in the day, the problem may have started with root rot. Or if you have squash vine borers, the millipedes will feed on the damaged stems. If you do think your problem is starting and ending with millipedes, I’d apply some diatomaceous earth (or Permaguard which is diatomaceous earth with pyrethrin) around the base of the plant and wherever it touches the soil. Do not use more than you have to however, as this will affect your earthworms also.

In any case, count on squash vine borers to cause problems with this crop. I recommend drenching the stems of your squash plants (especially at the base) with Thuricide (liquid Bt) at least a couple times per week and more if you have time. The moths will lay eggs at the base of your plants, but they will be protected when the larva hatches if it has to eat its way through Bt to get into the stem (the borers/larva will be dead before they can do any real damage). Keep an eye out for the moths which are active during the day. As you can see from the photo, they’re pretty distinctive. Kill them whenever you can, and increase the Bt treatments while they’re active.

 One more caution about watering. You’ll avoid a lot of problems simply by watering early and giving the plants time to dry before evening, but be aware that overhead irrigation will wash the Bt off the squash stems. Drip irrigation solves this problem and (since it does not get the foliage wet) relieves the necessity to water early. If this is not an option, you may want to increase the number of Bt treatments to replace product that has been washed off.

Frankly if I did not love yellow crookneck squash and zucchini as much as I do (and if homegrown squash did not taste so much better than what you get at the store), I would not go to this much trouble. But I do (and it does), so it’s definitely worth the extra work.

Safe Solutions - Mosquito Barrier Will Keep Mosquitoes Out of Your Yard!

You do not have to let mosquitoes chase you, your children and your pets out of your yard this summer. We sell a wonderful product called Mosquito Barrier that will keep the mosquitoes out. At first glance, it seems a bit pricy; but it’s a concentrate and a one quart bottle covers 1.25 acres. We also carry it in gallons. Still, if you’re on a budget like I am, you can stretch the product by using it only where you spend most of your time. I have used Mosquito Barrier around my back deck and from my front door to where I park my car (pretty much right in front of my front door – I live in a townhouse). That way I’m covered most of the time and a one quart bottle lasts me two to three months.

You may notice a strange phenomenon if you treat a small area like I do. When you approach the edge of that area, you may see mosquitoes swarming. Although you’re standing only a few feet from them, they will not approach you. It’s a little surreal . . . like there’s an invisible wall between you and the little blood suckers. They really will not approach you unless you step outside the treated area. Unfortunately if you do so, they will stay with you when you walk back into the treated area. When this happens, you’ll have to kill those pests that come into the area with you. Once you do, you’re mosquito-free again.

One application lasts for two to three weeks and will even continue to work after rainy weather (if it has time to dry thoroughly after application). The directions say you can use a pump or a hose-end sprayer, but we recommend you go with a pump sprayer. Oh . . . and be prepared . . . your yard will smell like an Italian restaurant for hours (or even days) after application.

Safe Solutions - Act now to avoid a grasshopper infestation this year!

If grasshoppers tend to be a problem in your garden, try Nolo Bait, an EPA registered biological control for grasshoppers. It contains naturally occurring Nosema locustae spores. These spores are applied to flaky wheat bran which attracts grasshoppers who then consume both the bait and the spores. Young grasshoppers consuming the bait will die more quickly than older stages, so the product is most effective when applied in the early spring. As Nosema locustae builds up in the gut of infected adult grasshoppers, they become lethargic and lose their appetite for your plants. In addition, infected grasshoppers are often consumed by healthy grasshoppers, which further spreads Nosema locustae throughout the grasshopper population. Infected females can also pass the spores through the egg-laying process.

Nolo Bait does not harm people, pets, birds, non-target insects, wildlife or the environment and is National Organic Program (NOP) compliant for use in organic gardens. Here at Native Nurseries, we carry it in a 1 lb. bag for $29.99. It is best applied during the morning as that is when grasshoppers do most of their feeding. To increase the effectiveness, split the bag into 3 or 4 applications several days apart (but never within 4 to 6 hours of rain).