Wood Borers

Wood Borers
- Genral Overview
  - Organisms
    - Common insect orders: coleoptera, hymenoptera, isoptera (lepidoptera)
    - Marine borers (not insects): teredos (shipworms) & gribbles (related to sowbugs/ pillbugs
  - For shelter and sometimes food as well
  - dry dead wood .... moist dead wood
  - dying trees ... healthy trees
  - some are slow to develop ... years ... after manufacture
  - some start feeding in phloem, then move to wood, others ... wood only
- Coleopteras
  - Cerambicids
    - aka long-horned beetles, roundheaded borers
    - generalized life cycle
      - generally attack weakened, dying, recently dead
      - lay eggs on bark
      - larva hatch and bore into bark
      - most start in phloem, then move to wood
        larva is 'roundish', refers to head/thorax
        prothorax has upper plate only
      - tunnels about the diameter of a pencil
        frass: exclesior ('wood wool, thin & curly), loose
      - typically 1-3 years as larva
    - may emerge from firewood in the house, not a worry
      - don't attack seasoned wood
    - sawyer beetles
      - Monochamus
      - some spp. vector the pinewood nematode
        cause of pine wilt disease
        serious issue for Japan & China ...
        ... quarantine issue for Asia & Europe
      - Asian Lognhorn Beetle
        not yet established in BC
        Toronto
        NY (Brooklyn, Long Island, Queens,) Chicago, New Jersey, Worchester MA.
    - timberworms
      - poderous borer - largest wood borer in BC (6-7 cm)
      - giant root borer
  - Buprestids
    - aka metallic beetles, flatheaded borers (short horned beetle, jewel beetles)
    - generalized life cycle
      - essentially the same as the cerambicids
      - larva has 'big shoulders'
        thorax is wide and flattened
        prothorax has upper and lower plate
      - frass is fine and tightly packed
    - western cedar borer
      - aka powder worm (not powderpost beetle)
      - eggs laid on branches, larva tunnels into branch, then to trunk
      - common on Cw in the south coast of BC (warm S-facing slopes)
      - usu. in heartwood
    - golden buprestid
      - attacks fire scars/ mechanical wounds on Fd & Py
      - known to emerge from furniture / log homes - decades later
      - found in S half of BC, preferred host is Fd
      - usu. just in sapwood
  - Ambrosia Beetles
    - covered in separate lecture
  - Powderpost Beetles
    - furniture beetles, death watch beetles
    - named due to the flourlike powdery frass
    - not real forest pest
    - attack wood-in-use - furniture or structural
- Hymenoptera
  - Carpenter Ants
    - infest trees and wood structures
    - fly in early summer in search of new home
    - colonial (thousands)
    - wood is for shelter, not food
    - tunnels kept clean and are very smooth
  - Wood wasps (Horntails)
    - eggs laid in wood of dead/dying trees - long ovipositor
    - also attracted to fire kill
    - larva feed on wood (2-5 yrs)
    - tunnels are pencil-sized, frass packed behind larva
    - adults: thick-waisted, metalic blue-black (some yellow markings)
- Isoptera
  - general
    - social insects with a caste system
    - do eat wood (cellulose)
    - colony is 'sealed' and contains frass
    - usu. found in stumps and logs
    - play a major role in recycling
    - cause > $1 billion damage annually in NA
  - Pacific Dampwood Termite
    - require wood with high moisture content (rotting logs)
    - major swarm flight in late summer
    - lose wings after mating
    - high predation rate, only a few pairs survive to start colony
  - Western Subterranean Termite
    - typically in 'buried wood' (rotting logs/stumps)
    - higher moisture content than dampwood termites
    - extend colonies via earthen tunnels ...
    - ... can connect to wooden structures
  - Drywood Termites
    - not in BC