We recommend you use Talstar P. Talstar P should be applied every 30 days at the 1fl oz per gallon of water usage rate from August through to the first frost. If you need to spray high areas you may need to use something like the Chapin Slide Pump Sprayer 6002. This sprayer is much different than most sprayers but there is a video located on the page we have linked for you that will show you how to use the sprayer.
You should reapply the Talstar P once a month through the warm season for best results. Please note that Talstar P will not offer an instant knockdown of insects, it will take several minutes to a few hours for them to die after they come into contact with treated areas. We also recommend dusting the carpenter bee holes with a dust such as Tempo Dust to help kill any larva inside. Do not plug the holes for at least 30 days after dusting to prevent the developing larva from drilling a new whole to exit.