February 13, 2017

When I first started gardening in my present location I had a real big problem with wire worms on my sweet potatoes. It took a little bit to ID them. This is always very important so you can determine the best ways to control them.

The wire worm is the larvae of the click beetle. These larvae are very common in native pasture lands where they feed on grass roots. My garden was native pasture land immediately before becoming a garden. So the wire worms were present and set to go to work.

One of the big problems with wire worms is they can stay in the larval stage for up to 5 years. These worms look a lot like the grubs I remember feeding to reptiles.

The wire worms are attracted to the CO2 that is given off by seeds as they germinate. With a huge population the seeds may be destroyed before they even emerge. They have a huge liking for corn. Which is one of the trap crops to monitor a population. When the corn emerges it is pulled up and any wire worm is tallied and destroyed. I have never had a huge population where crops have been devastated beyond sell able. But they have made some sweets resemble Swiss cheese.

They are active at two different times of the year: when the soil warms from 65 to 85 and then when the soil cools from 85 to 65. Large holes indicate spring feasting and clean smaller holes are fall feasting A funny thing while harvesting sun chokes (another tuber they will burrow into) I noticed several when I dug up the chokes (they died). This soil is not 65 degrees.

This year the sun choke was the only bed I noticed many but the troubling thing is there are very small ones all they way up to “adult “ sized ones.

Because they are in the ground there really are not many controls that work. It is odd that one year I noticed a lot of ground beetle larvae (known wire worm predators) and the next year continuing to this day they have been a very minimal pest.

As I noted above the wire worms are attracted CO2. So the addition of compost would draw them in. Now there is an interesting twist to this. Besides having wire worms I also have Root knot nematodes (RKN). One of the major controls of RKN is to add compost to the soil because there are bacteria in the compost that attack RKN. Ah yes always those balancing acts.

If agriculture was easy everyone would be doing it.