Two-Banded Longhorn Threat to Pine Plantations?

Two-Banded Longhorn Beetle, Rhagium bifasciatum

The most attractive family of beetles present in Ireland are easily the longhorn beetles (family Cerambycidae). With their distinctive antennae that are always at least two thirds as long as the body large size and often brightly coloured bodies longhorns should be quite conspicuous. However they are often difficult to find, mainly due to their life history. Larvae are found deep inside wood which they eat with their powerful jaws, often burrowing so deep into trees that adults have been known to emerge from furniture made from attacked timber (1). The adults of many species do not feed at all, but those that do feed on flower nectaries and a variety of plant material.
 

Two-Banded Longhorn Beetle, Rhagium bifasciatum

Of the 22 species of longhorn present in Ireland (2), one of the most common is the Two-banded Longhorn Beetle (Rhagium bifasciatum). While its antennae are not as impressively large as some of its relatives, it is nonetheless an attractive beetle sporting chestnut elytra that each show two slanted yellow bands. Economically, it has no direct effect on forestry activity as, although the adults do feed on conifer leaves, the larvae attack decaying softwood (3). However R. bifasciatum could be a possible vector for the pine wilt nematode Bursaphelenchus xylophilus (4), the causative agent of pine wilt, a disease that can kill established pine trees in weeks (5). Ireland currently does not have a problem with the pine wilt nematode, however strict quarantine must be used to avoid infection of R. bifasciatum in this country.

References:

1. McGavin, 2005. Pocket Nature Insects and Spiders pp. 112-113
2. Anderson at al., 1997. Irish Coleoptera.  A revised and annotated list.  Irish Naturalists’ Journal Special Entomological Supplement
3. Desch, 1973. Timber; its Structure and Properties p. 270
4. Robertson et al, 2008. Pine Wilt Disease: A Worldwide Threat to Forest Ecosystems Part IV pp. 221-234
5. Mota et al., 2008. Pine Wilt Disease: A Worldwide Threat to Forest Ecosystems