The yellow powder fallingfrom wooden furniture is called wood borer, it is required specialised service and patience for this problem as there are so many pin holes exits and we have to inject chemical into each and every holes.we may have to treat the area repeatedly for effective control. However the best way to control woodborer problem is the preventive measure of chemical spray on plywood before making furniture or sticking laminates or appluing paint, polish etc.

Post Beetle Control
Post Beetle