Smaller European Elm Bark Beetle(Scolytus multistriatus)Latin Name: Scolytus multistriatus
Common Name: Smaller European Elm Bark Beetle
Appearance:
The mature beetle is a dark reddish-brown beetle that is glossy and about 1/8 inch long. The bottom of the body’s back end is concave, with a visible protrusion or spine.
Larvae are little, white, grub-like insects that live beneath the bark of decaying or dead elms. The egg galleries run parallel to the wood grain, and the larvae feed across it.
The native elm bark beetle is another bark beetle that may be found in elms in Oklahoma. It measures less than 1/8 inch long and is dull brownish-black. It lacks a concave shape and the spine at the back of the body.
Their egg galleries run parallel to the wood grain, and the larvae eat in the same direction.
Host plants:
This species breeds all elm species, including the allied Japanese zelkova; however, Dutch elm disease is mostly a concern in American elm.
Territory:
Elm Bark Beetle is spread over the United States and the temperate parts of Canada and Mexico.
Damage caused by Elm Bark Beetle:
The native elm bark beetle feeds on healthy elms for a while before moving on to a dying tree for gallery formation and brood production. Because newly emerging adults transfer the illness to uninfected elms, adults are an effective vector of Dutch elm disease in American elms. The collection of boring dust at the tree’s base is the first sign of an attack.
Life history and Habits:
The European elm bark beetle is about 1/8 inch long, dark reddish-brown, and lustrous. Larvae are little white grubs that live beneath the bark of decaying or dead elms. In warm temperatures, the development of an egg into an adult beetle takes six to seven weeks. They cannot reproduce in healthy trees, but they can infect healthy elms with the Dutch elm disease pathogen while feeding. Smaller European elm bark beetles emit an aggregating pheromone, and host plant scents also help attract the beetles to vulnerable host plants. Each year, they have two to three generations.
