September 2006. From Thailand, what are these beetles that are burrowing in the living room furniture!

The pictures are not so clear, but members thought that it looks like a bostrychid, a kind of dry-wood beetle. There are three species, Dinoderus minutus, D brevis and D ocellaris, which are very common in Thailand and other Southeast Asian countries. All of them like to attack both bamboo and rattan furniture. D minutus is the most common species.

Fumigating each piece of your furniture is likely to be the best, but use of methyl bromide has been restricted. The alternative is to put your furniture in the sun for a few days; this will drive the beetles off. And after that coat it again with wood varnish. However, note that insolation may drive the adults off, but any eggs and larvae in the bamboo would not be killed. The next generation would continue the damage.

Freezing for a period of time would kill everything. However, if the temperature of the freezer is as high as -5°C, the furniture should be left for at least 2 weeks (3 weeks would be better, to make sure they were all killed by the cold). The lower the temperature of the freezer, the shorter the freezing time needs to be. At -27°C, a week would be sufficient.

Bear in mind that any other bamboo furniture in the same room may well have had eggs laid on it too, if you have adults emerging from the infested sofa.

There is a lot of information on this insect on the Internet. The following is taken from the CABI, CPC:

Physical Control
After felling, the physical or chemical treatment of culms can significantly improve their resistance to borers as well as to fungi. The traditional and simplest method is to immerse felled culms in water. This method may only be effective in preventing damage from bostrychid beetles. It is also only suitable for those bamboos with a low starch content. This method takes a long time and culms treated in this way tend to blacken. The heating of culms using fire, boiling water or exposure to direct sunlight in hot summers, can kill borers of D minutus including the eggs, larvae, pupae and adults. Some advanced microwave and infrared techniques have recently been developed for killing the borers in bamboo culms.

Chemical Control
Chemical treatment using various insecticides and preservatives has been the most widely used method in controlling post-harvest pests of bamboos, including D minutus. Various preservatives have been recommended and used in different countries: 5% water solution of copper-chrome-arsenic composition (CCA); 5-6% water solution of copper-potassium dichromate-borax (CCB); 5-6% water solution of boric acid-borax-sodium pentachlorophenate in 0.8:1:1 or 1:1:5 ratios (BBP); 2-3% water solution of borax: boric acid in a 5:1 ratio; and 10% or 20-25% water solution of copper sulphate. These are mostly applied by soaking under normal temperatures, cold or heated conditions, or under high pressure.

Soaking in an aqueous solution of 2% boric acid, 0.5% pentachlorophenate and 5% alcohol can treat bamboo rind and similar semi-finished products. There are reports of treating dried bamboo splits by immersing them in diesel oil as a simple and cheap method of bamboo preservation. Others have tested the effectiveness of several commercial formulations of insecticides against D minutus, and concluded that BHC and the two pyrethroids cypermethrin and permethrin, were effective. The two low-toxicity organophosphorus insecticides prothiophos and phoxim, were more effective than organochlorine ones for the preservation of bamboo materials against fungi and boring pests. Treating culm splits by immersing them in 0.2% phoxim for 3 minutes can result in total mortality of D minutus in the culm in 2 to 3 days, and can protect the treated split from attack for over 1 year. Affected bamboo material can also be treated by fumigating in closed chambers or storehouses with sulphuryl fluoride at a rate of 30 to 50 g/m³ of timber for 24 hours. Of course there is the usual methyl bromide. The problem with fumigants is that they have no residual effects.