Influence of Debarking and Insecticidal Treatments Using Cypermethrin on Fresh Logs of Indonesian Pine, Pinus merkusii, on Attack by Ambrosia Beetle, Xyleborus sp.

Problem statement: Indonesian pine logs (Pinus merkusii Yungh. et de Vr.) are vulnerable to attack by ambrosia beetle Xyleborus sp. Fresh cut logs kept for months in logging area are subject to heavily attack by the beetles. Approach: An experiment was conducted to evaluate effectiveness of debarking and insecticidal treatments using cypermethrin on fresh logs of the wood species on attack by the ambrosia beetle. Insecticide solutions of 0.5, 1.0, 2.0, 2.5 and 3.0% (v/v) were applied and the expeiment was kept in shady area for 60 days. Results: It was shown that debarking might increase the logs vulnerability. The beetle attacks on the untreated debarked logs (control) steadily increased from about 10 tunnels at the first week to about 80 tunnels per-square meter at the end of the experiment. Treatment with cypermethrin solution of 2.5% or more on debarked logs significantly protected the logs against the beetle. Meanwhile only a few tunnels were found on the bark-on logs at the first week and not more than 20 tunnels per-square meter at the end. Conclusion/Recommendation: The debarked fresh cut logs of the Indonesian pine should be treated with cypermethrin solution of 2.5% or more to prevent the ambrosia beetle attack Xyleborus sp. However bark-on logs are more preferred than the debarked ones because the bark will prevent the beetle attack and it is also environmentally more acceptable because no insectisidal treatment is required. Debarking process on the pine logs is also difficult so it will increase the production cost.