If you are having difficulty in making Mozzie observations, try some of these tips

Slap & Snap

First, try the old slap and snap. as long as you don't hit too hard dead mozzies are ok to ID.

Then take a picture from the side, this can be the best view, and don't wack it too hard.

Are you using a mobile phone or a camera?

If you are using a mobile then, can I suggest when taking the photograph, try taping on the screen this usually brings up a focusing square on the screen and prompts the phone to bring the mosquitoes into sharper focus.
otherwise, as previously stated, if you can get a side view that would make ID easier.

The Mozzie Monitors mosquito trap id a BG-GAT and can be purchased from 'Pacific Biologics' However, send @larissabrazsousa an email @ mozziemonitors@unisa.edu.au

FYI @colinpurrington has made blog on a home made version you could give that a go. You can follow him on Twitter @colinpurrington as I do he is really interesting.

Can mosquitoes be identified from an image of the wrigglers?

Yes, absolutely, but it is best to put them in a glass or container so they can be photographed from the side. This can be tough but i have seen some splendid examples

a Fantastic observation of Culex australicus © Rolf Lawrenz, some rights reserved (CC-BY) AKA @rlawrenz from Adelaide SA, Australia. check it out here
@rsmalley