Could you modify a mosquito to inject poison with cyberware? On the other hand would it be better to just make a mosquito drone, and if so how would you make one?

You can do that using biodrones from Augmentation.

You're in luck, Arsenal include the Dragonfly minidrone. Just tear out the old special machinery and replace it with an injection system.

A Dragonfly is too big. If you had a mosquito sized drone, you could just send it along with some real mosquitos and, assuming the dose is small enough, basicly be unnoticed when it delivers it's payload.

The Biodrone Swarms in Augmentation talk about getting chemical glands and injection ports.

Dont do this !!

I have had a similar idea almost 15 Years ago in my Star Wars campaign. The plan was to capture the PC's with roboter dragonflys which poisen them with some narcotics so the "evil" guy could catch them.

The players was angry about that and get mad because they couldnt do anything against this and in the end this caused the breakup of my gameing group.

Just my two cents,
Meschler

Nah, be mean and, instead of using Neurostun or Narcoject, use something like HMHVV, Ebola Plus, or Gamma-Anthrax.

Or the bloodboiling "Deus special".