Antenna Architecture and Pheromones

Pheromones are one method used by many insects to communicate and navigate their world. According to Tom Eisner, an entomologist and ecologist known as “father of chemical ecology”, each insect may rely on approximately 100 different pheromones in its lifespan. These pheromones are used for finding food, protecting nest sites, escaping predation and finding mates. However, unlike sound and sight signals, pheromones travel slowly and do not fade quickly resulting in effective communication over a long range. One group of insects that have highly developed antenna for pheromone transmission and receiving are moths.

Male moths are especially keen on using pheromones in order to detect the opposite sex. Males in the moth families Saturniid (giant silkmoths, royal moths and emperor moths), Bombycid (silkworms), and Lasiocampidae (snout moths, or lappet moths) are known for their more decorative and impressive feathery antenna. This group of moths includes Emperor, Polyphemus, Vaporer, and the loveable Luna moths. These beautiful plumes are equipped with an enormous quantity of hair like structures containing incredibly responsive olfactory receptors – up to 60,000 in some species. These structures are capable of detecting a SINGLE molecule of a female sex hormone from miles away. At this rate there might be only one pheromone molecule per cubic yard of air! Therefore, moth antenna are constructed to come into contact with the largest possible volume of air, making them superb scent receptors. A major portion of their development during pupation is entirely given to the construction of this efficient piece of equipment for reproduction. The next time you stumble upon a moth – take some time to gaze at these incredible structures.

-Meghan Pearl & Kevin Clarke

image credits: Main Image