Guild Wars 2

No matter how many times I kill a mosquito, ambient or otherwise, it doesn’t drop the item I need for the achievement. All the other creatures dropped their respective items on the first kill. I tried switching characters, but that didn’t help either. I am a:

Human
Warrior (Elementalist, for the second character I tried)
Borlis Pass
I attempted to kill mosquitos in many different areas, including Bloodtide Coast, Sparkfly Fen, and Caledon Forest.

When I killed a mosquito in Dry Top it worked