Female butterflies use smell to avoid inbred males
Just like in humans, when an animal breeds with a relative, their offspring will most likely have genetic disorders. Inbred males are weaker, less able to provide for their families and have lower defense mechanisms. How does a female butterfly know if a male is inbred? “New research reveals that inbred male butterflies produce significantly less sex pheromones, making them less attractive to females” (SD, 2012).
All of the characteristics used by males to attract a mate are diminished by being inbred. For example, males exhibit less color, song or acoustic abilities when they are inbred. The significance of this relates to species survival. If a female mates with an infertile male, she will not produce any offspring, eventually leading to extinction in small isolated populations.
Butterflies are very important to the environment. They are good pollinators and their larvae are an important part of the food chain (Desert museum, 2013). Read more about butterflies here.
To read the complete study on butterfly pheromones, please see the reference below.
SD (Science Daily), 2013. Females Butterflies Can Smell If a Male Butterfly Is Inbred. Online. Available at:
E. van Bergen, P. M. Brakefield, S. Heuskin, B. J. Zwaan, C. M. Nieberding. The scent of inbreeding: a male sex pheromone betrays inbred males. Proceedings of the Royal Society B: Biological Sciences, 2013; 280 (1758): 20130102 DOI: 10.1098/rspb.2013.0102
Desert Museum, 2013. http://www.desertmuseum.org/books/nhsd_butterflies.html