Round Up, however it won't do a thing to a bug. Under no circumstances would you want to use a pesticide that kills all BUGS because it kills the soil.

Killing off your existing Bermuda is more than a challenge, but here is th ebest way for a DIY's

Wait till the weather is good and warm so the Bermuda is growing aggressively. Fertilize your existing grass, water it for a week and let it get up to at least 3 inches. Then hit with Round UP PRO Dry mixed for 4%. Use a teaspoon of liquid dish soap for every gallon mixed.

Wait 4 days, and scalp the yard bagging the clippings.

Hit it with the same RU potion, wait another 4 days.. Then regrade or topdress with a sugar coat of soil or sand and lay the sod down or plant your common Bermuda seed.