Bugs On Squash

Michelle RobertsGardening


There is a bug that is very attracted to the squash plant and it is called the Squash Bug (Anasta Tristis).  It never  ceases to amaze me that they find the squash plants no matter where you plant them in your garden.  This year my squash are half an acre away from where I planted squash last year.  It has probably been 3 years since I had squash in this bed.  Last year and the year before there were no signs of the squash bug – yet this year, I have discovered numerous adult bugs on the squash vines.

They are easily identifiable with their grayish black “shield” back.  They overwinter in debris laying near the garden bed.  Those that reach the adult stage before winter will survive through the winter.  They  become active when the weather turns warm in the spring and move to wherever there is squash germinating.  They can migrate from quite far, so control of this bug is always ongoing.

By June they are laying eggs which are very unique, golden, oval shaped, very hard,  a bit larger than pin head sized. They are typically laid in groupings on the underside of the squash leaf.  If these eggs hatch and the nymphs survive,  they will grow to adulthood, mate, and hatch out another generation of nymphs before the cold weather sets in.  The nymphs that make it to adulthood will overwinter in debris left around the garden beds until the next season. That is a good reason to clean up the garden beds in the fall.

Squash bugs are often the most destructive insect pest of winter squash and pumpkins.  Both nymphs and adults  attack the plants by sucking sap from the vines of the plants causing enough damage to prematurely kill the plant.  To the unknowing gardener, the  squash plant will look just fine one day, and the next day it will be wilted and obviously dying.  Once it hits the wilt stage, bringing it back is doubtful.

Controlling bugs on squash requires diligence and persistence.  Make frequent inspections of your squash plants.  I pretty much expect that they will be there sooner or later and I’m just looking to identify when they have settled in.  Cold winters are helpful in destroying squash bug populations – one of the few good things about cold winters.  Mulches will help them survive.  Mulched squash plants harbor far more squash bugs than those planted in bare ground.

Diatomaceous Earth spread around the base of the plant will provide some control – especially for the new nymphs as their bodies are still soft and will be exposed to the diatomes.  Sprays made with soap, oil, and water will penetrate the shell and offer some control.  Pyrethrins and Pyola also offer good organic control.  Squash bug patrol is a good job for the young gardener.  I often have younger children locate the bugs, then squash them between two rocks. I just recently read a gardening blog by Andrea Meyers where they were vacuuming them up with a wet/dry vacuum – hilarious! but hey, if it worked for them, maybe I’ll give it a try – my luck would be that I vacuumed up the whole plant!

Locating the eggs is another job the younger children can do.  However, those eggs are hard to destroy as the shells are so hard and sprays are ineffective on them. Dislodging them and having them fall to the ground does not destroy them. What I have found effective is to take a small, stiff, artists paint brush and an ice cream bucket around.  After finding a grouping of eggs, I set my bucket under the leaf and brush the eggs into the bucket.  I’m pretty careful about what I do with that bucket too as those eggs can hatch anywhere.  Most times I just put the lid on it and set it in the sun until the egg laying season is over, then I throw it away.  We use all the above methods to control bugs on squash and spend some time searching for the bugs or the eggs.  It is a bit labor intensive, but well worth the time.