Every year at this time Mark and I check out The Chestnut Tree. Three years ago we stumbled upon the tree and a bumper crop (I'm not telling where, so save your breath) but the last two years have been disappointing. This year we found seven (not good). That's how it goes with foraging: sometimes it's feast, sometimes it's famine.
So when my friend Lisa said her father had sent a surplus of chestnuts and asked if I'd like some, I leaped at the chance. Visions of chestnut soup, chestnut pudding, candied chestnuts danced in my head. Those visions did NOT include wriggling maggots on my kitchen counter.
Surprise! When I opened the box, I stroked the warm, brown surfaces of the nuts. So pretty, so smooth. Then, underneath the chestnuts, something moved. A pulsating, 1/4 inch long, white maggot with a brown head. And another. And another. Not so pretty.
Never one to be deterred by a little additional protein, I tossed the hole-y nuts and their resident maggots, assuming the remainder of the chestnuts were sound. Wrong. A few days later there were more maggots than I cared to count. A quick email to Lisa confirmed that her nuts were also entirely yucky. And she had already eaten a few!
Lisa warned her dad and we've all learned a lesson. A lesson I'm going to share with you:
Once upon a time there was a chestnut weevil (a kind of beetle). It lived in the ground during winter and emerged in early summer. It flew around and around, and being a female weevil, in the fall it drilled a hole (with its super-long proboscis) through the nut's burr (the spiky outer covering) and into the nut meat. Then it laid eggs in the hole. 10 days later the eggs hatched and larvae developed. When the nut fell to the ground each maggot chewed a hole to escape the nut and dig into the ground. They overwintered there for one or two winters before emerging, pupating, and beginning the cycle all over again.
It's a happy story (for the weevil), but you can destroy that insect happiness by simply picking up chestnuts as soon as they fall. If the larvae don't have a chance to dig into the ground, they can't develop into beetles, can't lay eggs, can't turn into chestnut-eating-maggots. You'll need to do this for 3-4 years to make a real difference. Of course you could just spray in spring, when the adult weevils emerge, but interrupting the life cycle is a pesticide-free way of controlling the insect.