Any of the following.
Sigma 105mm
Tamron 90mm
Nikon 105mm
The tamron is the cheapest, but sill great IQ, it extends a lot during focusing The sigma is good, but extends considerably during focusing too.
The Nikon doesnt extend, has VR and is much better built, but will be more expensive.
There are also 60/70mm macros, but I wouldn't advise them for bugs, as you have to get too close to the subject to fill the frame. Longer the better really.