The simple answer is that true maggots do not consume wood. A maggot is the larval stage of a fly, such as a house fly or a blow fly, and their biology is fundamentally unsuited for digesting the cellulose and lignin that make up wood fiber. When people observe a larva tunneling through wood, they are almost certainly looking at a different type of insect larva specifically adapted to that challenging diet.
The True Maggot Diet
The diet of a true maggot is narrowly focused on moist, decaying organic matter. Maggots are nature’s recyclers, specializing in breaking down rotting flesh, spoiled food, animal feces, and damp compost. Their rapid growth cycle demands a nutrient-dense food source that is easily digestible, high in protein, and high in moisture content.
Wood, even rotting wood, lacks the necessary nutritional profile for maggot development. Hard cellulose and lignin are difficult to digest and contain very little protein required to fuel the maggot’s transformation into an adult fly. Flies seek out decomposing waste and carrion, not wood, to ensure the emerging larvae have an immediate and abundant food supply.
Identifying True Wood-Boring Pests
The larvae responsible for consuming or boring into wood are primarily from the order Coleoptera (beetles) or social insects like termites. These wood-destroying organisms have specific biological adaptations, such as gut microbes or specialized enzymes, that enable them to break down wood fiber. The most common culprits are the larvae of various beetles, collectively known as wood borers.
Powderpost beetle larvae bore into the wood, reducing it to a fine, flour-like dust known as frass, a tell-tale sign of their presence. Longhorn beetle larvae, often called roundheaded borers, can live in wood for years, creating large, oval tunnels before emerging as adults. Other insects, like carpenter ants, do not eat the wood but excavate galleries to nest, leaving behind piles of coarse, sawdust-like material.
Termites are significant wood-destroying pests, but they are social insects that live in colonies, not larvae. They are true xylophages, meaning they actively consume and digest cellulose as their primary food source. Different species target different types of wood, such as drywood termites that feed on sound lumber, or subterranean termites that require contact with soil and moisture.
Understanding Larval Terminology
The confusion between maggots and wood-boring larvae stems from a misunderstanding of insect terminology. “Larva” is the general scientific term for the immature stage of any insect that undergoes complete metamorphosis.
A maggot is a specific term reserved for the legless, worm-like larva of a fly, characterized by a lack of a distinct head capsule. In contrast, the larva of a beetle is correctly called a grub. A grub is typically a fleshy, C-shaped creature that possesses a hardened head capsule and sometimes has thoracic legs. When someone finds a white, segmented creature in wood, it is almost always a wood-boring grub, not a maggot.
The term “borer” is simply descriptive, applied to any larva that tunnels through material, including the grubs of beetles. Recognizing the physical differences between a legless fly maggot and a stout, distinct-headed beetle grub is the first step in correctly identifying a pest and determining the appropriate course of action.