[AG-EQ] Dragonflies and mosquitoes

[Jewel]

I am sending this query to several of my lists as it doesn't seem to be, entirely, appropriate to 
any of them, but there may be a cupboard biologist on one of them who will know the answer.
Last night, when I was playing my daily iphone game of "Seven Little Words", the hint was "A bug 
that eats mosquitoes"?  and the answer was "dragonfly".
Given that the dragonfly is a creature of the day, while their prey is of the night, how does the 
first hunt down and devour the second?

         Jewel