This Week in Bugs: The Squash Vine Borer 2


Bug scale rating:  -3*

People wax poetic about the arrival of spring’s first harvest–the asparagus and the strawberries and the radishes that remind us, no, winter won’t last forever.  Not me, though.  My heart belongs to fall.  Every September, my stomach fist pumps at the sight of the first winter squash–the hand-painted look of the delicatta’s oranges and greens and the mini-pumpkin cuteness of the kabocha.

This year’s sighting, however, was tinged with a hint of sadness.  My mind drifted back to the heart of the sweltering summer–the days when the zucchini promised, yes, you poor schmucks, the summer is going to last forever.  My mind drifted back to this…


The decimation caused by the Squash Vine Borer.  Wyck lost most of this year’s kabocha harvest to the voracious appetites of these brutal flesh eaters.  So, what’s going on in these pictures?  This is the result of squash borer larvae entering the base of the squash plant and feeding off the tissue for 4-6 weeks.  The damage inflicted to the basal stem prevents the plant from properly absorbing the water it needs.  Once the plant begins to wilt, there’s nothing to do but mourn.

Check out this description from the Penn Sate College of Agricultural Sciences.  It make you question the merits of organic agriculture:  “Squash vine borer eggs are about the size of a pencil point, brown and flattened. Larvae have a brown head, white body and are rarely found outside of the vine. The larvae have 8 pairs of appendages from their body. The first 3 pairs are true legs, the second 5 pair are prolegs or extensions from the body wall. Each proleg has 2 rows of curved spines.”  Mother Nature, this is unacceptable.

Next year will be different, though.  Next year, I’ll look at that beautiful fall harvest and feel nothing but pride and joy.  Well, assuming we can take this advice to heart…

University of Minnesota Extension

National Sustainable Ag. Information Service

University of Illinois Extension

*The Bug Scale is a made-up scale ranging from -5 to 5. Negative designations are given to harmful insects.  Positive designations are assigned to beneficial insects.  The number value is almost entirely arbitrary.