Squirrel season has been open now for about two weeks, and I understand that many hunters have had success harvesting their share of the game. However, some of those early-season squirrels offered slightly more protein than hunters wanted at their tables. 

Mr. James Allen called last week to report he and his son did some hunting up in the Delta National Forest and they had pretty good luck on their trip. Unfortunately, when Mr. Allen’s son returned to Florence with the dressed squirrels and soaked them in the refrigerator, he noticed something else wiggling around in the container. That prompted a call back to his dad and Mr. Allen’s subsequent call to the Extension office.

Based on Mr. Allen’s description, I suspect what his son was seeing coming from the meat were fly larvae. There does happen to be a fairly common fly in the Oestridae family, subfamily Cuterebrinae here in Mississippi that we call the botfly, warblefly or wolves, which will infect squirrels. For those of you who like species names, this critter is Cuterebra emasculator. 

These larvae enter the squirrel’s skin after the female flies lay eggs near the nest or directly on the fur of the host. The flies don’t just pick on squirrels. They will select other rodents, too, such as chipmunks, mice, rats and voles. After the eggs hatch, the grub-like larvae occupy cavities in the subcutaneous connective tissue of the host just below the skin. These cavities possess an opening to the outside that provides oxygen to the developing fly larvae.

The larvae are normally more of a problem to squirrels in late summer to early fall. One of our Mississippi State University’s wildlife specialists did a study in the late ’70’s and discovered squirrels are infected with these botfly grubs from about mid-August thru late October. They also tend to be more of a problem in bottomland hardwood forests like in the Delta National versus forests containing some pine timber in the hills. To complete development, larvae emerge from the ‘warble’, drop into leaf litter at the base of trees and pupate. Squirrels simply serve as an intermediate host for a relatively short period of time, but are necessary for the flies to complete their life cycle.

Neighborhood squirrels or urbanized squirrels probably have much less of a problem with botflies, because there is less leaf litter than in the woods, so the flies don’t have the microhabitat necessary for pupation. Squirrels in forests, on the other hand, are commonly infected.

Obviously, the botfly larvae and the ‘warble’ in which they reside on the squirrel can look disgusting, but neither apparently do any harm to the squirrel. The entry/exit wounds rarely become infected by bacteria. It takes the fly larvae a total of about 3 weeks to exit the squirrel through the warble before it drops to the ground to burrow into the soil and pupate. I am pretty sure Mr. Allen’s son decided to dine on something other than the squirrels they harvested from their hunt. However, if they get a chance to bag some squirrels this month, it is doubtful that they will encounter similarly infected game.

Reminder: Winter Flower Selections — First Tuesday Gardening Series with Donna Beliech, Extension horticulture agent.  Tuesday at noon in the Extension conference room.

John C. Coccaro is county Extension director. Write to him at 1100-C Grove St., Vicksburg, MS 39180 or call 601-636-5442. E-mail him at jcoccaro@ext.msstate.edu