Yikes! Beetle Larvae in Your Holiday Ham!

By Chris Williams on December 19, 2016.

For the holidays, a good friend gave us an “old country ham” that she purchased at a farm market. Apparently, these are hams that are cured or dried unrefrigerated for a year or more. They look terrible with mold on the surface (that’s normal) but supposedly taste great. The problem is that we have seen holes in the ham and a few black and yellow beetles crawling on the ham! Any idea what’s going on? B. E., Pembroke, NH

I do have an idea, but you’re not going to like it. Aged hams can actually be infested by a couple of beetles that feed particularly on meats and cheeses, and dried fish, among other animal-based products. The redlegged ham beetle is one and the larder beetle is another. Based on your description, I would say that your holiday ham has been infested with larder beetle larvae (see Larder Beetles Infest Meats).

The adult larder beetle is about 1/3-inch long, oval-shaped, and dark brown with a pale yellow band across its middle. There are six dark spots in the banded area. The larvae are slender, about ½-inch long when fully grown, and are brown with long, dark hairs, a small brown head, and two curved spines at the rear end.

Larder Beetle Larvae Tunnel and Feed Within the Ham

An adult female larder beetle will lay her eggs directly on a ham in storage. Hatching larvae will chew through any wrappings on the ham and will tunnel into the ham to feed beneath the surface. They will be fully grown in about 2 months and will exit from the ham. They then bore into wood or other nearby materials to pupate, or sometimes they chew a pupation hole right in the ham. Since the feeding larvae are hidden under the ham’s covering, an infestation is often not noticed until the adult beetles appear. When a ham is aging for long periods, it can be repeatedly re-infested by several generations of beetles. Needless to say, a heavily-infested ham is ruined by the larval feeding.

If you’re sure the beetles are coming from the ham, you should wrap it up securely and discard it in the trash. The emerging beetles fly and they could infest foods, hides, woolens, and other items in your home. You’ll want to be careful if you have your infested ham in your kitchen or anywhere near other foods, even near dry pet food. You can have Colonial Pest inspect the area and, if necessary, treat for wandering beetles.

Larder beetles are not common food pests in homes today. They were much more common before the days of household refrigeration when drying meats and storing them in a larder was common practice.

Photo Credit : By Rjb uk at English Wikipedia – Transferred from en.wikipedia to Commons., Public Domain, Link



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