Xyleborus

ambrosia beetles, bark beetles

Xyleborus is a of in the ( Scolytinae). These small woodboring are characterized by their obligate symbiotic relationship with , which they cultivate in galleries carved into trees and use as their primary food source. Several have become significant pests, including Xyleborus glabratus (redbay ambrosia beetle), which the fungus causing laurel . The genus includes both and species with varying degrees of .

Xyleborus by no rights reserved, uploaded by cgmayers. Used under a CC0 license.

Xyleborus glabratus by no rights reserved, uploaded by cgmayers. Used under a CC0 license.

Xyleborus affinis by (c) Arturo Santos, some rights reserved (CC BY), uploaded by Arturo Santos. Used under a CC-BY license.

Pronunciation

How to pronounce Xyleborus: //zaɪˈlɛbərəs//

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Habitat

Woody substrates; occupy various including living trees, dead wood, and roots. X. glabratus colonizes trees in Lauraceae. X. germanus bores into tea roots at approximately 30 cm depth. X. compactus occupies tea twigs 5–8 mm in diameter.

Distribution

range centered in Asia; multiple globally. X. glabratus: native to Southeast Asia, introduced to Georgia (USA) in 2002, established in nine southeastern US states with potential for further spread to California, Mexico, and tropics. X. ferrugineus and X. volvulus: present in Mexico with extensive climatically suitable areas in Chiapas, Tamaulipas, Veracruz, and Jalisco. X. fornicatus: recorded across Asia (Bangladesh, India, Indonesia, Malaysia, Philippines, Sri Lanka, Taiwan, Vietnam), Africa (Madagascar, Réunion), and Pacific islands (Fiji, Hawaii, Papua New Guinea, Solomon Islands).

Diet

cultivated on gallery walls; feed on fungal spores and mycelia. Not woodfeeders; xylomycetophagous.

Life Cycle

Overwinters as . X. germanus and X. compactus: two per year. X. germanus generations occur June–early July and late August–September. X. compactus generations occur late July–late August and late August–September. Optimal rearing temperature 21–23°C for X. germanus, 25–27°C for X. compactus.

Behavior

Females initiate gallery formation and carry fungal spores in specialized mycangia (internal storing organs). Cultivates fungi on gallery walls for larval nutrition. X. glabratus females Raffaelea lauricola, the causal agent of laurel . No known for X. glabratus; primary are volatile terpenoid from Lauraceae.

Ecological Role

of woody material in ; nutrient cyclers through fungal . act as of pathogenic , causing tree mortality and forest ecosystem disruption. X. glabratus has caused extensive mortality in native Persea and threatens avocado production.

Human Relevance

Several are significant agricultural and forestry pests. X. glabratus threatens $65 million Florida avocado and Lauraceae forests. X. compactus and X. germanus are pests of tea plantations in Asia. incur substantial management costs; programs for X. glabratus use lures (phoebe , manuka oil, cubeb oil, and (-)-α-copaene enriched ).