Mind control wasp

Hymenoepimecis argyraphaga is a Costa Rican parasitoid wasp whose host is the spider "Plesiometa argyra". The wasp modifies the spider's web building behavior to make a web of very strong lines. This supports the wasp's cocoon without breaking in the rain.
Reproduction.
The adult female wasp temporarily paralyzes the spider and lays an egg on its abdomen. The egg hatches into a larva. The larva sucks the spider's blood through small holes, while the spider goes on about its normal web building and insect catching behavior.
When the larva is ready to pupate, it injects a chemical into the spider. This causes the spider to build a web whose design is completely different from any it has ever made. Then the spider sits still in the middle of the web.
The wasp larva then moults, kills the spider with a poison and sucks its body dry before discarding it and building a cocoon that hangs from the middle of the web the spider has just built. The larva pupates inside the cocoon, then emerges to mate and begin the cycle over again.