The acorn weevil is a member of a genus of weevils called Curculio. Related species include the pecan weevil, chestnut weevil and filbert weevil. Not surprisingly, the nut from the oak tree plays a prominent role in the life of the acorn weevil. This article will discuss how female weevils manage to lay their eggs inside the hard-shelled nut, and how the acorn benefits the weevil larvae as they grow.
Identification and Detection
A fully grown adult is typically about 3/8-in long and mottled brown in color. The specific coloring allows it to blend well into its surroundings.
A female acorn weevil has a particularly long snout or beak that is ideal for creating holes in acorns, thanks to the saw-like teeth at its very end. The snout has a hollow center which allows the weevil to feed on liquids and plant matter. In some cases, this protrusion is actually longer than the female’s body.
By contrast, acorn weevil larvae will be off-white in color, legless and quite robust. The presence of acorn weevil larvae is detected by examining acorns in the area and looking for holes. An infested acorn may have one or more holes in its shell. One can break open the shell to look for the C-shaped larvae and/or evidence of feeding.
Reproduction and Life Cycle
Early in the growing season, an adult female will lay her eggs in a young acorn after she first gains access to the nut by drilling a hole in the shell. After the eggs are laid inside the acorn, the weevil plugs up the hole with her own feces. Just a few days later, the eggs hatch and legless, C-shaped grubs emerge. These larvae are typically 1/4 to 3/8-in long. They grow by feeding on the matter inside the acorn.
In the fall, a grub bores a hole in the acorn shell in order to escape into the surrounding soil. It will burrow down into the ground, and it becomes invisible to possible predators. Once the weevil has burrowed into the soil, it may stay there for as long as two years before it finally emerges as a mature adult.
Squirrels and Infested Acorns
Squirrels often ignore these infested nuts, because they appear to have an innate ability to gather only the “good” nuts. Children are often tempted to collect acorns and bring them into the house. If any of these acorns are infested by acorn weevils, the home’s occupants may be greeted by the sight of wiggly grubs on floors or counters.
There are both natural and chemical controls that may be employed to deal with acorn weevil infestations. To learn more about pest control and the acorn weevil, contact Clegg’s online or via phone at 888-672-5344.