WHERE are you going??? If on an inside passage round trip cruise, nope you won't need any. But if going interior and to Wonder Lake before mid August, bring a gallon. ( I no longer will go there before the end of August myself any longer). Frankly- MOST areas gone to by "tourists" have a bug problem to worry about.
We're going on a land/cruise tour in July -- am I correct that I will need to really spray myself down extremely well for the 7 hour Tundra Wilderness Tour in Denali?
We went to Sanibel Island last year and I ended up needing medical care due to the vast number of 'no-seeum' bites I received. My husband only had one or two bites --- I was so covered it was like I had the worse case of chicken pox you can imagine -- and even with medication it took almost 2 weeks for them to disappear. ------- Some people are more susceptible then others and I've always been extremely susceptible to mosquito and no-seeum bites.
Our land tour will start in Fairbanks and then go to Denali; Talkeetna; Anchorage; Alyeska, and pick up the ship in Seward -----------------Do I need to spray myself down with Deet anywhere else besides Denali?
You aren't going in far enough in Denali Park for the significant bug problems at Wonder Lake- mile 85. The Tundra Wilderness tour only goes to mile 53. Take precautions if really prone, but I would speculate, you won't need it. The "tours" don't go to big bug areas.
They sell mosquito repellant everywhere. Mosquitos are only bad in certain areas, mostly in the tundra where the caribou get attacked by them. If you are camping out or at a picnic, just apply a little repellant or lite a citronella candle. When the wind kicks up, the mosquitos are gone. The bugs are nothing to compare with the southern U.S.
You won't have any problems on the ship. However, we noticed a lot of mosquitos when we were hiking and rafting in Skagway las week...I had a couple bites. But the locals say the first batch of the season is "slow and stupid". The second batch are big, fast and smart.....so WATCH OUT!