Pheromones

What are pheromones

Pheromones (from Greek pherein — to carry, horman — to excite) are chemical substances released by an animal into the environment that affect the behavior of others of the same species. In butterflies, pheromones are the main means of finding a mate.

Female pheromones

Females of most species release sex attractants — volatile substances that attract males from great distances. Pheromones are produced by special glands at the tip of the abdomen. The female “calls” males by raising the abdomen and releasing a cloud of pheromone on the wind.

This mechanism is used to control pest moths: pheromone traps attract males and prevent mating.

Male pheromones

Many day-flying butterflies also produce pheromones — via androconial scales (specialized scales on wings or legs). Androconial scales release substances that stimulate the female to mate at close contact.

Example: the male monarch (Danaus plexippus) has conspicuous androconial patches on the hindwings.

Pheromones and systematics

A species' pheromone profile is unique — two closely related butterflies, indistinguishable visually, may have completely different pheromones and not interbreed. This allows “cryptic species” to coexist in one area without hybridization.

More on mate search — in the article life cycle.