get some mosquito dunks that have BTi (bacillus thuriengensis israelensis) in them. crush it up and put a few tblsp under your soil where it's moist. that bacteria will kill the larval stage and end your infestation.
i've never seen those yellow things before tho, if those are gnat larvae BTi will take care of them.
BTk is for caterpillars. you want BTi.
you can get coated bits like this too https://www.amazon.com/Mosquito-Summit-Dunks-6/dp/B07G9M6QTP
Mosquito Summit Dunks (6 Dunks) (1, 30 Ounce) https://www.amazon.com/dp/B07G9M6QTP/ref=cm_sw_r_apan_i_VYTZHJ7V7NBS7EK7DXFH