She tells me it's only a certain kind of mosquito, and just the female.
That's true. Only some types carry some diseases.
National Geographic says:
"There are more than 3,000 species of mosquitoes, but the members of three bear primary responsibility for the spread of human diseases."
http://animals.nationalgeographic.com/animals/bugs/mosquito/
Only female mosquitoes bite and suck blood. And they only do it before they lay eggs. Blood is not the normal food source for mosquitoes.
Again, National Geographic:
" Only female mosquitoes have the mouth parts necessary for sucking blood. When biting with their proboscis, they stab two tubes into the skin: one to inject an enzyme that inhibits blood clotting; the other to suck blood into their bodies. They use the blood not for their own nourishment but as a source of protein for their eggs. For food, both males and females eat nectar and other plant sugars."
I actually learned this from watching an episode of Wild Kratts with my son. He loves that show.
The odd thing about Dengue fever is that the first time you get bit by a mosquito with it you don't usually have any terrible symptoms requiring the hospital. It's the second infection that causes the super painful symptoms. Luckily, if you go to the hospital quickly you're unlikely to suffer long-term consequences.
Here's the CDC website for Dengue with precautionary tips eetc:
http://www.cdc.gov/Dengue/
I plan to use plenty of bug repellent when we go to Hawaii. And avoid early morning and late afternoon outdoor time.