Worm-like Mass

Does anyone know what this is?
(This is not a test because I do not know the answer.)

When I first saw this growth on a dead hickory tree, I thought it was a mass of worms, but it isn't. Each on of the "worms" is mostly air, so light that it will float in the air on even the most gentle of breezes. I suspect they are fungal spores of some type.

Worm-like Mass

Laurel Sphinx Moth (Sphinx kalmiae)

Laurel Sphinx Moth (Sphinx kalmiae)

From Butterflies and Moths of North America:

Family: Sphinx Moths, Hawkmoths (Sphingidae)

Subfamily: Sphinginae (Sphinginae)

Identification: Forewing is yellowish brown with a thin whitish line along the outer margin and a black patch along the inner margin. Hindwing is tan with a black border, black median line, and black patch at the base.

Life history: Fully-grown caterpillars pupate in cells dug in loose soil. Caterpillars of the second brood pupate and overwinter.

Flight: . Probably two broods from March-October.

Wing span: 2 15/16 - 4 1/16 inches (7.5 - 10.3 cm).

Caterpillar hosts: Laurel (Kalmia latifolia), lilac (Syringa vulgaris), fringe tree (Chionanthus virginicus), privet (Ligustrum), ash (Fraxinus), poplar (Populus), mountain holly (Nemopanthus mucronatus), and northern bush honeysuckle (Diervilla lonicera).

Adult food: Bouncing bet (Saponaria officinalis) and Japanese honeysuckle (Lonicera japonica).

Range: Newfoundland and Maine west to Manitoba and North Dakota; south to Alabama and Louisiana.


Thanks to the Moth Guy at BugGuide for confirming my ID.


My apologies for the unattractive background, but most of my moth photos are taken out on the porch because the moths are attracted to our porch light. Taking the photo of the moth on the porch seems better (to me) than capturing it and setting up a more attractive presentation later -- but that's just the way I choose to do it.

Laurel Sphinx Moth (Sphinx kalmiae)

Oak Timberworm (Arrhenodes minutus)

Oak Timberworm (Arrhenodes minutus) - Male

Oak Timberworms are sexual dimorphic (i.e. males and females do not look the alike). Males have broad and flat, pincer-like mouthparts while females have long slender snouts. Females use their snouts to chew tiny holes in various hardwoods. They oviposit one egg in each hole, then usually seal the hole with a sticky secretion and frass. Oak Timberworms -- which are actually beetles -- are attracted to wounds on living trees and oviposit only on exposed sapwood. Both sexes feed on sap at wound sites.

(Note: Jim McClarin has an excellent series of photos showing a female boring a hole and ovipositing posted on BugGuide.)

Egg incubation requires anywhere from a few days to three weeks, depending upon temperatures. Newly hatched larvae bore directly into the wood. That's when the real damage to the timber begins. Typically, tunnels are bored nearly straight across the wood grain with little up or down slope. Tunnels go almost to the opposite side of the tree, make a sharp U-turn, and go back across the wood grain toward the entrances. Larvae keep the tunnels clean by pushing the frass outside. Pupation occurs near the tunnel exit from which the adults emerge. The life cycle is generally 3 years, but some individuals develop in 2 years and a few require 4 years.

Known hosts trees include oak, elm, popular and beech. Many other hardwoods including boxelder, honeylocust and aspen are suspected of being susceptible to infestation. These beetles also serve as vectors for oak wilt fungus. They range throughout most of eastern North America from Canada to the Gulf of Mexico.

Sources and links:
BugGuide Species Page
Forest Pests
University of Florida

Oak Timberworm (Arrhenodes minutus)