Squash Vine Borers
Pest of the Week
squash vine borers
When strong, healthy zucchini plants wilt and then collapse into piles of yellow mush, blame the squash vine borer. This inch-long white grub with a brown head is the larvae of an orange and black clearwing moth (Melitta curcurbitae) that grows about ½ inch long.
In late June or early July, adult squash vine borers lay eggs at the base of squash and pumpkin vines (and sometimes cucumbers and melons). The hatched larvae crawl inside the stems to feast there for several weeks. The larvae block the flow of water to the leaves, which causes the plant to wilt and eventually die.
By the time you see wilting and yellow mush (called frass), the plants are most likely beyond saving. But you can prevent these larvae from becoming adults and laying eggs that will destroy next year’s crop. Either cut the vines lengthwise to find and destroy the white caterpillars inside or pull up affected crops as soon as they finish bearing and destroy them. Next year, set out traps for the adults: any yellow bowl or pan filled with water. If you see brownish eggs near the base, pick them off.
—text by Elizabeth Noll, photo courtesy of the Kemper Center for Home Gardening at the Missouri Botanical Garden
Monday, September 05, 2011 7:31 AM
To prevent the infestation in the first place, add wood ashes to the soil when you plant the seeds or sprinkle ashes ontop of the soil after planting or after plants emerge.
Monday, September 05, 2011 4:10 PM
I will try this. these darn beetles ruined my yellow squash this year. My first time ever having them
Tuesday, September 13, 2011 4:40 PM
That's what happened to my squash also. I was so excited because this is the first year for our raised beds and was looking forward to eating some squash. I will try the wood ashes. Thanks for the info.
Tuesday, September 13, 2011 7:48 PM
Dipel will work wonders as well.
Tuesday, September 13, 2011 8:13 PM
Would charcoal ashes work? I prefer not to use insecticides.
By Extra Dirt Newsletter
Wednesday, September 14, 2011 9:08 AM
Sunday, September 25, 2011 2:03 PM
Thank you! I did cut open the first squash vine affected and killed the worm. I thought that I had caught the critters early enough and treated my plants with BT, thinking worms. Now I know what to look for.
Thursday, October 13, 2011 11:06 AM
The squash bugs on my plants are grey and flat. They are on the stems and leaves and suck the moisture out of the plants. I think they lay eggs on the underside of the leaves. Is this the same bug or worm family? They ate or destroyed my zuccini plant then went onto my crookneck and spaghetti squash plants. They don't seem to bother anything else but squash. I rotate where I put my squash every year but they find them anyway. Help!!!!!
Thursday, October 27, 2011 2:20 PM
could that be why i didnt even get 1 pumpkin
Monday, November 14, 2011 12:19 PM
Do they live in the Southwest (Yuma, AZ)?
Wednesday, November 23, 2011 10:20 AM
I'm in Phoenix and get the flat grey bugs. they kill my scallop squash and my zucchini if I dont keep a close watch on them. they start with the zucchini.
Saturday, March 03, 2012 9:40 PM
We have an ongoing battle with squash bugs that are the gray flat type and are similar looking to stink bugs. We have found them overwintering around the base of buildings. Squash, zucchini and pumpkins are all devastated.
Wednesday, March 14, 2012 12:04 PM
help!!! I have a big problem with my Milkweed plants.( food for Monarch larvae) There is a bug like the squash beetle, and small yellow insects (like mites) I cannot use insectiside because I will kill the Monarch caterpillars. What can I do? Right now I have many Monarch and they eat the plants so i am forever replacing the milk-weed I don't need anything else killing the plants. What can I do to eliminate these pests. My daughter is picking and squashing them be hand but they are impossible to eliminate this way.Help! Help! So. Florida.
Thursday, May 24, 2012 8:23 AM
how do i get rid of the SQUASH BUGS. theses are the gray kind????
Saturday, June 09, 2012 10:06 PM
I read something online that squash bugs do not like petunias, you might try planting that around your milkweed and or squash. Not sure if it works but worth the try
Tuesday, June 19, 2012 10:04 AM
I am also having huge issues with these horrible pests! They have taken out my radishes as well - anything that has moisture in it! I'm in Payson, AZ and they seem to get worse every year. Rotating hasn't helped either. Will try wood ashes and HOPE! Neem based products didn't even touch them, nor did the old dish soap trick! Anyone that sees results from what they do, please post as I'm really frustrated with these pests! THANKS!!
Tuesday, July 31, 2012 9:02 AM
I have had the same problem in the past with summer squash and was about to give up when I read about planting raddishe's with my squash and letting it go to seed so I did and to my suprise and delight I have had a great crop of summer squash this year.
Thursday, August 23, 2012 11:29 AM
For the squash vine borer: After the seedling has grown a few inches, wrap aluminum foil around the stem, from the first set of leaves, down to a little below the soil line. This "collar" will prevent the borers from laying their eggs.
Monday, January 07, 2013 4:18 PM
Now I know what was devouring my zuccchini and cantalope. I will try the wood ash this year. I need to clean the fire pit out anyway! Fleming Island, FL
Tuesday, January 15, 2013 6:39 PM
last year was my 2nd year of raised bed gardening, first year they totally took out squash and then cucumbers (yellow mush) i did not plant squash last summer but did cucumbers and cantaloupe, i kept an eye out for the eggs they lay on the bottom of the leaves (gold to bronze colored) i first saw eggs on a cantaloupe, so i went through the whole plant and picked off every leaf that had eggs and put in a bucket with soapy water, i only found a few adults and did same with them. i also put self rising flour on stems especially around the roots this helped me to not lose entire crop tho i sure would not recommend this as a cure (was not a fun chore), something i did around cucs was plant marigolds around them to deter them with smell(did detour them considerably}, i was going to try onions or garlic too this year, will also try your suggestions. oh reason for flour was i read it could kill adults if they ingested it.
Monday, June 10, 2013 9:01 AM
I read about planting zucchini in mid to late June. Tried it last year and no borers. Zucchini likes colder weather so they performed well into the fall.