We were there Nov 14-21 and I had tons of bites all over my body, mostly my legs. My husband however didn't have any! I took bug spray, but I don't think it helped...heck it might have made them attracted to me since I got bit and my husband didn't!
Yes you will want to bring bug spray for a Dec. vacation. This will be our 4th Dec. at CSA and I get bit bad by sand fleas (also called no seeums) every time, obviously 1st time was the worst because I wasn't prepared but ever since I make sure to spray well especially when we are hanging on the beach at night (bonfire, beach dinners, etc.). I don't bring anything with deet and have been fine *fingers crossed* we are coming back this week and I look forward to minimal bites ha ha
We were there at the same time as you, normally I am a mosquito buffet, had 28 bites on one leg once. Anyway whilst i was there I was only bitten 3 times, twice by mosquitos and once by an ant. I used a spray from Boots in england called Repel. This seemed to work for me. We also sunbathed mostly by the pool instead of the beach so i think that helped as well. I have tried most things to repel insects (including the supposedly good Avon Sking so soft spray) but based on results the spray from Boots worked for me.