Overview

Xyleborus glabratus is native to India, Japan, Myanmar, and Taiwan. It was first discovered in Georgia in 2002. It has spread to infect redbay, sassafras, and other Lauraceae trees in most southeastern states. It is suspected to have been introduced in solid wood packaging. 

Life Cycle

Xyleborus glabratus adults are small, 0.08 in. (2 mm) long, slender, cylindrical, and brown-black in color. It is very similar to other members of the genus but the combination of its coloration, glabrous elytra, and abrupt declivity distinguishes it from other species (Mayfield and Thomas 2006). Eggs are small, oblong, and white-translucent.  The larvae are 0.04-0.08 in. (1-2 mm) long, white, c-shaped, legless grubs with an amber colored head capsule (Rabaglia 2005). A specialist should be consulted for positive identification of adults and larvae due to their similarity to other species. Adult females construct galleries in the sapwood and inoculate the galleries with a fungus (Raffaelea lauricola, vascular wilt pathogen) (Mayfield and Thomas 2006, Rabaglia 2005). The adults and larvae feed on fungi and not on the wood of the damaged host plant. Females are believed to be able to fly 2-3 km in search of a host (Rabaglia 2005). Males are dwarfed, haploid, and flightless and are rarely encountered (Rabaglia 2005). Very little is known about the life cycle and biology of Xyleborus glabratus, but it is assumed to be similar to other species in the genus (Mayfield and Thomas 2006). Most of the life cycle takes place within the galleries, where beetles mate, lay eggs, and young develop. There are multiple, overlapping generations per year with brood development occurring within 50-60 days.

More Info

Most native ambrosia beetles attak dead or dying trees, but this species will infest healthy trees and death can occur in weeks to months. Symptoms of infestation include sawdust "toothpicks" extending from the trunk, blue stained wood and feeding galleries beneath the bark, and wilted foliage. 

Never transport any part of an infected tree, as the beetle and its associated fungus can move in wood. Cut and chip the infected tree and leave it onsite or at least dispose of it locally. The Don’t Move Firewood campaign is aimed at slowing down the spread of this and other forests pests.

Resources

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• Pest Alert - Florida Department of Agriculture and Consumer Services
• Pest Reports - EXFOR Database - US Forest Service
• Website - USDA Forest Service Southern Region

Selected Images

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Invasive Listing Sources

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• Everglades Cooperative Invasive Species Management Area
• Florida Invasive Species Partnership
• Invasive Species of Concern in Georgia
• Maryland Invasive Species Council - Invasive Species of Concern in Maryland
• National Cooperative Agricultural Pest Survey Target Species - 2015
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• North American Forest Commission Exotic Forest Pest Information System

References

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Common Name Reference: Bosik, J. J. Common Names of Insects and Related Organisms 1997. Lanham, MD: Entomological Society of America (ESA), 1997. 232 pp.

Scientific Name Reference: Wood, S.L. and Bright, D.E. Jr. 1992. A Catalog of Scolytidae and Platypodidae (Coleoptera) Part 2: Taxonomic Index Vol.A. Great Basin Naturalist Memoirs No.13. Brigham Young Univ.,Provo,Utah, 833pp.