Holes in Acorn Squash

Asked September 25, 2019, 10:29 PM EDT

This yr i grew acorn squash for first time on land that was not used for min 20-40 yrs, so it was disappointing that the 3 plants were soon attacked by vine borer and then squash bugs by the hundreds despite my daily smashing and insecticidal soap spraying. After fruits finally formed i noticed small frass piles along vines and on the fruit. There were also BMS and cuc beetles around the garden, and lack of rain certainly was stressful. The vines wilted early, leaving most of the squash quite small. As i cut, cured, then brought them in i noticed several had holes as in 2 pics attached. Obviously it takes a lot to penetrate the hard shell, so are holes from another generation of borer or something else? Presumably those fruit are ruined, or could that section be carved out as with an apple if used soon?

Anne Arundel County Maryland vegetables pest insects and mites

3 Responses

Hi- there are a number of beetles, caterpillars as well as birds and small mammals that will feed on, or attempt to feed on, immature winter squash. Squash vine borer does not bore into fruit, just stems.

It's more likely that the injury occurred prior to the hardening of the fruit skin.The good news is that it looks like the injury is somewhat superficial. Wipe down and dry fruits (you could also immerse them in a 1% bleach solution to kill pathogens on the surface, then rinse and dry). Store them in a cool, dry location with good air circulation around the fruits and monitor for secondary rot pathogens around the wounds.

So much for that theory! Attached are pics of acorn squash that was completely hard and normal shell, but had a bored hole pictured in orig question. As you can see, the outside flesh looks completely normal, but the cavity is dark brown and the seeds are loose. I did not see the perpetrator.

Hi- sorry to hear that your fruits are ruined. The initial caterpillar feeding allowed entrance to pathogens and other insects, like fruit flies. There was plenty of moisture in the flesh to attract and support those secondary pest problems. Better luck next year.