LC50 value of pesticide

It's LD50, and it's specific to whatever chemical you're using.

LD50 = Lethal Dose to kill 50% of a population.

Thanks for the answer. I am so confused. I have ready-to-spray pesticides and testing these against lady beetles and need to calculate LC50 values for each pesticide. My plan is to spray the filter papers with pesticides, dry them for like 20 minutes and let the beetles walk on them (will perform in petri dishes) and count mortality. First, my problem is I don't know what volume that I need to spray. (If the paper is still drenched after 20 minutes, that will kill more beetles). Let's say I am going to use 50 mL of the total solution to spray.  For LC50 values, I am going to dilute  the pesticides by reducing the volumes to 45mL, 40 mL, 35 mL, etc and mix with 5mL, 10mL and 15mL of water respectively. So, I will get 45 mL of pesticide/ 50mL of solution. My confusion is what does this ratio means in term of standard concentration units like mg/L or ppm. To make it simple, what does 45mL of ready-to-spray pesticides mixed with 5mL of water mean in the units of mg/L or ppm? If you have better plan on how to start this whole thing, I truly appreciate.