Dr. Yves Le Conte taking a photo of his indoor hives at his lab. Yves works on honey bee division of labor, semiochemistry and varroa mite biology. He is best known for identifying brood pheromone, a group of 10 simple esters that are secreted by larvae and pupae to signal their age, so that workers can cap them at the right time. These chemicals have many other functions, one of them is to act as attractant for varroa mites to enter the cells, just before worker or drone larvae are sealed. March 16, 2002.