Having not been on holiday anywhere like the Caribbean or Thailand or anywhere exotic, I couldn't say how effective this product is on foreign strains of Mosquitoes, but, as one of those unlucky people, who always gets bitten within five minutes of going anywhere, I can confirm this product was a godsend when used on a recent UK camping holiday, and even though we were camped close to water, and spent allot of time outside in the evenings, we managed to come back bite free.
Couple of things I would point out, even though it does state cautions of use on the packaging:
1) Do not spray anywhere near yours eyes (or anyone else's who is unfortunately standing next to you). It STINGS like hell !!!
2) If you've sprayed it on your arms, always remember you have, because later when you go to wipe sweat out of your eyes with the back of your arm, IT STINGS LIKE HELL !!!
3) If you take a drink and go to cuff any residue from your mouth with the back of your hand, always remember you have sprayed them too, because it's like rubbing raw fresh chilli pepper seeds into your lips. IT STINGS LIKE HELL !!!
In seriousness, whilst it says skin friendly on the bottle, I would recommend anyone with sensitive skin to try a small dab somewhere before liberally applying.
Yes its feels slightly sticky/oily when you apply it, but it seemed to wash off quite easily in the shower and didn't seem to leave any nasty aroma afterwards.