We prepared for the worst on our trip to Palau, based upon travels to bug-ridden places like Australia and the Bahamas. We sprayed our tent with permethrin. We sprayed our clothes with permethrin. We carried bug spray.
It was a wasted effort.
What we encountered in Palua — while camping on beaches and a jungle shoreline, and walking through heavily-overgrown areas — was a surprisingly low level of annoying insect activity. There were only a few mosquitoes at any given time, and no biting gnats. We only encountered flies around the cooking areas of established campsites, and even then it was not bad. Compared to Australia and the Bahamas, Palau is bug-free.
The worst mosquito activity we encountered was on Peleliu, when we penetrated the overgrown areas of Umurbrogol. It warranted bug spray, but was still fairly light.
The most annoying bugs were the sand fleas that were active along the waterline of some beaches. They loved Jen, but avoided me. Even with Jen, they could be avoided by not stopping on the small strip where the water met the sand.
The lack of biting insects and flies was one of the great pluses of our trip to Palau.