Hickory Shuckworm
Cydia caryana
A small gray-black moth whose larvae feed inside the shucks and nuts of pecan and hickory. Early-season feeding drops young nuts, and late feeding ruins kernel fill and makes the shuck stick to the shell.
🔎 How to spot it
The adult is an inconspicuous, night-flying gray to smoky-black moth about three eighths of an inch long with a roughly half-inch wingspan, marked with dark and light flecks near the wing tips. The larvae are white to cream colored with brown heads. The visible signs are dropped nutlets and dark frass at entry holes in the shucks.
🥀 Damage it causes
First- and second-generation larvae tunnel into small developing nuts and cause them to drop, while the most damaging later generation mines the shucks after the shells harden, reducing kernel fill and causing the shucks to cling tightly to the shell. Yield and quality both suffer. Pecan and hickory are the hosts.
🛡️ Prevent it
Rake up and destroy fallen nuts and shucks during and after the season, since the insect overwinters in old shucks on the tree and on the ground. Removing this overwintering habitat lowers the next years population. Keeping the orchard floor clean is the foundation of home control.
🧯 If it is already here
Where sprays are warranted, begin at about half-shell hardening and repeat at roughly two-week intervals until shuck split, using a labeled material such as spinosad or an insect growth regulator that is easy on beneficials. Sanitation combined with well-timed sprays gives the best result. There is no way to reach larvae already inside a nut.
💡 Good to know
There are about three generations a year, and the insect overwinters as larvae and pupae in old shucks. The damage is hidden inside the shuck and nut, so dropped nutlets and stuck shucks are often the first clues. Cleaning up mummified shucks left hanging in the tree is as important as raking the ground.
For educational and informational purposes only. Pest control advice is general guidance drawn from university cooperative extension sources; always identify a pest positively and read and follow the label on any product before use, especially around food crops, children, and pets.