I was asked by a flooring distributor to look at some insect damage to a rubberwood parquet floor. Rubberwood is pretty susceptible to insect attack. Holes were appearing in the surface of the floor, so there was a possibility of an active infestation. The distributor was concerned that the insects were in the whole container of flooring… and that would mean other floors could have the same problem.
The flooring was glued to a slab in a garage that had been converted to living space. A local pest control company had treated the house recently, so termites had been ruled out. I was shown several areas where holes had developed in the floor. The holes were bigger than a powder post beetle hole, and more like a large grub hole. None of the holes obviously continued from one board to the next.
Too big for PPB's, so I could rule them out. Pre-existing insect holes would not connect across multiple boards, so this was still a possibility. Termites wouldn't normally eat all the way to the surface, but I had surface holes. And the house had been treated recently. Some live, foreign bug sounded like a possibility, but I needed to find one.
So, I started taking the floor apart. The first thing I noticed was there were tunnels that extended from board to board. This indicated an active infestation. The next thing I noticed was that the tunnels were through the adhesive. See the V-shaped lines on the floor and back of board:
I followed the tunnels and came to a crack in the slab. A little more poking around, and I uncovered a termite in the slab crack.
Some of this floor had been covered with a rug, so a termite could have eaten all the way through the surface. Another possibility is that the termite ate all but the surface, and foot pressure then caved in the thin surface layer, opening the hole up. In all, it was a fun investigation, and the distributor was thrilled that the cause was site-specific and not a whole container load. But I didn't find a new, possibly invasive bug like the emerald ash borer.
