Mel M Kelly wrote:

What do they hurt? They don'e bite do they?

They are turning my grass yellow.

But I've taken action recently and I've applies a bag of grub killer
followed up with a hose-end spray of several jugs of liquid grub
killer. Active ingredient is Sevin (Carbaryl).

I believe that in my area, that early to mid october is the best time to
apply Carbaryl to treat crane flies (aka leather jackets or
leatherjackets) as they feed in their late instar growth stage. I will
probably treat the area again in the spring to kill the damn things.

The crane fly is NOT native to US/Canada, and by not eradicating it we
are allowing a non-native species with no natural predator to become
endemic in our ecosystem. That is NOT a beneficial outcome for our
environment.

Same is true for the emerald ash borer. Thousands, if not millions of
ash trees (many of them healthy and un-touched) have been cut down to
stop the spread of the ash borer.