When we went last year in April we never needed to wear any mosquito repellant. It is truly a paradise! And usually my freckled husband gets eaten alive. But he did not get one bite in ten days. So you might not need it at all.
However my wife would rather sleep in a poisonous snake invested room accompanied in bed by a couple of man eating crocs than sleep without the pleasure of being covered head to toe in mozzie repellent, she tends to over use it a little. So I was a little concerned in case we ran out!