What the... Not that I'm complaining, but that was weird.

The Jewel Wasp.

Excerpt:

The venom injected into a specific part of the brain of the cockroach doesn’t actually affect the general motor skills of the roach.  At this point, it’s perfectly capable of fleeing, if it could be motivated to do so.  The problem is that the venom actually seems to inhibit the cockroaches desire to flee from potential danger and even pain, specifically by inhibiting the ability of the cockroach to begin complex behaviors, such as walking.  The venom does this by blocking a specific neurotransmitter called “octopamine”. Once they are coerced into moving, they can walk just fine, though they have trouble forcing their body to continue to move.

[...]

About three days later, which is coincidentally about the same time the venom will begin to wear off, a little larva is hatched and proceeds to feed on the delectable roach.  But the fun doesn’t stop here.  The larva doesn’t actually eat all the roach right away.  No, the roach is still quite alive when the baby wasp chews into its abdomen and proceeds to live there as a parasite.  Over the next week or so, the larva eats the roach’s internal organs generally in such an order that the roach will stay alive for quite some time (four or five days).  Once the larva has eaten all the innards of the roach and the roach dies, it then forms a cocoon inside the cockroach’s body from which a full grown wasp eventually emerges.

...This would make a great plot idea if I was more into horror...

*sigh* Well, prepare for a big dump, everybody!