Thursday, August 13, 2015

The Insidious Vine Borer

The vine borer moth is an insidious creature. It looks like a wasp, but it does not sting. Thank goodness for that at least. This moth is a fast flyer, but in the early morning hours you can find them resting on leaf surfaces. All the better to squish the little buggers.

Each moth lays about 200 eggs, so can you imagine what happens when these pests show up in numbers.

In my garden, the moths seem to prefer zucchini, but they will lay eggs on just about any type of squash including yellow straightneck, delicata, acorn and tatume. I've even heard of people complaining that the moths were attacking their cucumbers. Jeesh. I hope that doesn't happen to mine.

The eggs hatch into worms that burrow into the squash plant and begin eating from the inside. There is no easy way of dealing with this annoying pest. The worms are protected against potential sprays because they stay tucked inside the stem. When the damage becomes severe, the plants will begin to wilt and struggle to survive.

The tell tale sign that a vine borer is eating the plant is the frass that appears along the stem. All that chewed up plant material has to go somewhere.

When the worms get their fill, they crawl down into the soil and pupate in their cocoons.

I started growing tatume squash because it has the ability to re-root at the leaf nodes. The vine borers still attack, but the plant is able to survive and continue to produce fruit.

Growing tatume squash on a trellis support is probably not the best idea because the plant does not have as much contact with the ground as it needs to continue to survive against the borers.

The vine borers were particularly destructive this year. The moths overwhelmed the plants by laying eggs at all the leaf nodes.

I could tell the plants weren't doing well, so decided to go ahead and remove them. I cut through the vines with my pruners looking for the worms.

After finding 73 worms in just four plants, I realized that these plants had become a vine borer nursery providing the perfect breeding ground for more moths. 

I disposed of all the infected tatume vine, but the fascinating thing is that I have other tatume squash growing that is completely unaffected by the borers. I wonder why? I'm going to save the seed from the unaffected plants and see what happens next year.