Keith Mickler column: Squash not looking very fit

 

 

 

By Keith Mickler, County Coordinator and agriculture agent for The University of Georgia/Floyd County Cooperative Extension

 

While out visiting my vegetable garden yesterday I noticed this cute little adorable bug, which was quite colorful flying around my squash and zucchini. I proceeded to watch this little critter, thunk about what it doing and blurted out "no you didn't". Dadgum, blasted critter, you be a squash vine borer moth. Well, needless to say, all that cuteness was gone and I was gone to get my bug killing stuff. How dare this sorry thing visit my garden, it don't know who it's dealing with now does it?

 

If you ain't figured it out yet, this cute and colorful flying bug is the dreaded squash vine borer which is the number one suspect behind the demise of our squash and zucchini. This bad mamajama has come on quickly due to high temperatures the past few days. My friends just north at the University of Kentucky have this to say about the sorry ole squash vine borer.

 

Squash vine borer is a key pest of squash, gourds and pumpkins in the south. Unfortunately, it is usually noticed only after it has done its damage. Symptoms appear in mid-summer (ha, summer started here 6 months ago) when a long runner or entire plant suddenly wilts. Infested vines usually die beyond the point of attack.

 

Sawdust-like frass (squash vine borer stinky) near the base of the plant is the best evidence of squash vine borer activity. Careful examination will uncover yellow-brown excrement pushed out through holes in the side of the stem at the point of wilting. If the stem is split open, one to several borers are usually present.

 

The caterpillars reach a length of 1 inch and have a brown head and a cream-colored body. Unlike most moths, they fly about the plants during the daytime, appearing more like a wasp than a moth.

 

This insect overwinters as a full grown larva or a pupa one to two inches below the soil surface. The larva pupates in the spring, with the adult moths begin to emerge about the time the plants begin to run, and moth flight continues through mid- August. The small brown eggs, laid individually on leaf stalks and vines, hatch in seven to 10 days. The newly hatched larva immediately bores into the stem. The larva will feed for 14 to 30 days before exiting the stem to pupate in the soil. There are 1 to 3 generations per year.

 

Management

The key to squash vine borer management is controlling the borers before they enter the stem. Once inside the vine, insecticides are mostly ineffective but there is always a slight chance of hope an insecticide might kick'em it the tail.

 

Adult emergence occurs at approximately 1000 degree days in the early summer, well we are at 1300 on May 31. This usually corresponds to mid-June around here not late May as the start of the adult flight.

You can also use yellow traps to detect squash vine borer adults. This can be any container (pan, cup or bowl) colored yellow and filled with water. Because squash vine borer adults are attracted to yellow, they will fly to the container and be trapped when they fall into the water. Place traps now. Check your traps at least once a day. When you notice squash vine borer adults in your traps you know they are active and it is time to take further action. Like I did yesterday, kicking butts and taking names

 

Use two insecticide applications (such as bifenthrin or esfenvalerate) 7 days apart to control newly hatching larvae and continue to monitor for additional activity. Sprays need to penetrate the canopy and down to the soil line to be effective.

 

Some home gardeners have had triumphant victories with deworming the vines. At the first signs of the sawdust-like frass, vines are slit lengthwise near where the damage is found and the borers removed. The stems should be immediately covered with soil. Burying a few nodes along each vine will encourage rooting at these nodes. This will lessen the impact if squash vine borers girdle the base of the vine.

 

When all else fails and you can stand it no longer, visit your local farmers market for your squash fix, no one has to know you didn't grow'em. Heck place a few of them bought squash out among  your dying plants to sooth the anxiety.

 

Keith Mickler is the County Coordinator and agriculture agent for The University of Georgia/Floyd County Cooperative Extension. Located at 12 East 4^th Ave, Rome, GA 30161 (706) 295-6210. Office hours are Monday-Friday 8:00 a.m. - 5:00 p.m.  The University of Georgia Cooperative Extension - Learning for Life. Agriculture and Natural Resources, Family and Consumer Sciences, 4-H Youth.  An Equal Opportunity/Affirmative Action Institution. To obtain extension publications please visit our web site www.ugaextension.com or contact your county Cooperative Extension office.