BBCnews is carrying this report detailing DARPA's recent efforts at creating controllable insects for use in combat situations. The primariy stumbling block does not in fact appear to be inserting control electronics:

What adult insects want to do is basically reproduce and lay eggs. You would have to rewire the entire brain patterns.

However, tricking the insects into thinking explosives are food (and thereby causing them to swarm) seems to be more promising. Unfortunately, that too failed in the face of the same stronger imperatives to eat and, well, boink.

Hey, when your lifespan is measured in weeks, ya gotta have priorities!