Parity can be determined by the ovary tracheoles. If the mosquito is nulliparous, the tracheoles are arranged like a tree with fruits on it's tips. The tracheoles form these knots like balls of yarn. When the mosquito has already laid eggs, these "balls of yarn" on the tips of the tracheolar tree become untangled and now the tree looks like if it lost all its leaves and fruits. This cannot be seen in the video because we used a stereoscopic microscope, you need to place the ovaries on a slide and a coverslip to see them in the compound microscope. Also, if you find that the ovaries are enlarged and full of eggs, then you can't tell if this is the first batch of eggs or the mosquito has already laid other batches before.
How do you know if its parous or nulliparous?
Parity can be determined by the ovary tracheoles. If the mosquito is nulliparous, the tracheoles are arranged like a tree with fruits on it's tips. The tracheoles form these knots like balls of yarn. When the mosquito has already laid eggs, these "balls of yarn" on the tips of the tracheolar tree become untangled and now the tree looks like if it lost all its leaves and fruits. This cannot be seen in the video because we used a stereoscopic microscope, you need to place the ovaries on a slide and a coverslip to see them in the compound microscope.
Also, if you find that the ovaries are enlarged and full of eggs, then you can't tell if this is the first batch of eggs or the mosquito has already laid other batches before.