The first step to mating for pollinators is to locate and recognize potential mates, which is quite the endeavor for tiny creatures in a big world. The most common way for pollinators to find mates is by emitting pheromones, or chemicals that can be recognized by other members of the same species. Other methods used by pollinators and other insects include acoustic messages and flashes of light or color (think fireflies or brightly colored butterflies). As you may guess, species that rely on bright coloration and patterns to attract and identify mates typically search for mates during the daytime, while species that use pheromones, acoustics, or flashes of light often search for mates during the dark of night. Once potential mates have located each other, a variety of courtship rituals take place. Males may stroke females, flutter their wings, or perform flights or dances to try to impress females. If these courtship rituals are deemed suitable by females, mating will finally commence.
Here are two examples of these behaviors in pollinators found in Pennsylvania:
First is the ornately patterned Eastern Black Swallowtail (Papilio polyxenes). During the mating season males establish territories on sites that are easily visible to females, such as hilltops, and then aggressively chase other males out of their territories. Females circle these areas observing the interactions between males, until finally choosing the most competitive males. The new pairs engage in courtship flights before finally mating.
Conversely, the Rosy Maple Moth (Dryocampa rubicunda) is a nocturnal species and therefore must rely on non-visual cues to locate mates. During the night females release pheromones, which males can sense using receptors in their antennae, legs, and palps (prongs coming from the mouth area). It is not known from how far away males can sense the females, but in some butterfly and moth species females can be found from up to 10 miles away!! Once males have located and been accepted by females, mating takes place on the undersides of leaves, where females will lay their eggs about 24 hours later.
Author: Amber Wiewel
Donald Hall, University of Florida (Eastern black swallowtail)
Emilio Concari/iNaturalist (Rosy maple moth)