Insects with xylophagous larvae
CAPRICORN (Hylotrupes bajulus)
- Shafts and galleries parallel to the wood thread wherein wood dust is present.
- 5 - 10 mm oval-shaped exit holes.
- 20 - 25 mm long, ivory-white colour (larval cycle 3-5 years).
- 10 - 20 mm long , deep brown colour.
- Lifetime : 2 - 3 weeks.
- Egg laying : 40 - 100 eggs.
VRILLETTE (Anobium punctatum, Xestobium rufovillosum)
- Lumber (softwood and hardwood) often infested by rot fungus.
- Shafts and galleries parallel to the thread of wood.
- 1 - 3 mm round exit hole (4 mm for the deathwatch beetle).
Common furniture beetle :
- Arched body, 5 - 7 mm long, white colour.
- Larval cycle : 1 - 4 years.
- 2,5 mm - 5 mm long, deep brown colour.
- Lifetime : 3 - 4 weeks.
- Egg laying : 20 - 30 eggs.
Deathwatch beetle :
- Arched body, 6 - 11 mm, white colour.
- Abundant hair.
- Larval cycle : 1 - 10 years depending on the level of fungal attack.
- 5 - 7 mm long.
- Deep brown colour with tufts of yellow hair.
- Lifetime : 9 weeks.
- Egg laying : 100 eggs.
LYCTUS (lyctus linearis ou brunneus)
- Hardwood (including tropical woods).
- Numerous shafts and galleries blocked with sawdust.
- 1 - 2 mm round exit holes.
- 5 - 7 mm long, white colour.
- Larval cycle : 8 - 12 months.
- 3 - 6 mm long, reddish brown body.
- Lifetime : 2 - 6 weeks.
- Egg laying : approx. 20 eggs.
CARPENTER BEE (Xylocopa violacea)
- Any soft wood species (hardwood and softwood)
- Large galleries of 10 - 15 mm diameter and up to 45 cm long
- Woodchips are rejected ou of the timber
- Visual : looks like a bumblebee
- Colour : black body with purplish wings
- Size : 20 - 25 mm long
ANTS (Hymenopteran formicidae)
All wood species may be attacked by ants. However, ants will prefer to aim woods which have been already faded by fungi.
- Tunnels and galleries : large cavities with clear and smooth finished walls without worm-hole
- Wood chips and remains of insects are rejected outside
- Will vary according to the species
- Camponotus herculeanus : 7 - 14 mm long, reddish brown colour
- Lasius niger : 2 - 4 mm long brown colour
- Lasius fuliginosus : 3 - 5 mm long, bright black colour
Treatment against insects and xylophagous larvae
Each case requires a specific treatment. However, these processes are complex and only skilled professionals should be contracted.
- Probing the timbers : Run a mechanical check of the timbers to detect mines and galleries.
- Chopping the damaged timbers : everywhere and infestation has been detected, get rid of the damaged wood and remain only with the sound wood exposed.
- If ever the mechanical resistance of the timber appears to be weaker than expected, double-check with a certified architect.
- Brushing and cleaning : brush and clean any mine/gallery to evacuate frass in order to ease the product penetration into the treated area.
At this stage, a biocide will be used to stop larval development and prevent new egg layings.
2 routes are possible for treatment :
- Injection and spraying of liquid biocidal products
- Coating of surface by biocidal gels (specific cases)
In both cases, timbers and wood in contact with masonry (brick walls, concrete blocks) will be treated by injection.