136: Roach sex pheromones

Science -- Nojima et al. 307 (5712): 1104:

The sex pheromone of the German cockroach, Blattella germanica, has been characterized as gentisyl quinone isovalerate. This cockroach is a major cause of allergic disease and serves as a mechanical vector of pathogens, making it one of the most important residential and food-associated pests worldwide.

Sex pheromones evolve just like cricket calls or rodent penises. Understanding the product of the mechanism that allows roaches to meet each other is key to preventing all manner of diseases.