The effect of wing color on Heliconius melpomene mating behavior and its implications on the evolution of mimicry

Wing color is important to butterflies both for social signals and protection from predators. Butterflies gain protection from predators by having aposematically colored wings that warn the predator that the butterfly is distasteful. Some butterflies are also part of Mullerian mimicry complexes in which two distasteful species converge on the same color pattern to enhance their aposematic protection. Heliconius erato and Heliconius melpomene are Mullerian mimics that exhibit a wide variety of wing patterns throughout Central and South America. Their wing patterns have greatly diverged within each species, but between the species they are almost perfect mimics in each area. It has previously been found that H. melpomene prefer to court butterflies of their same color pattern race. This study examined a possible mechanism of this racial isolation by investigating the effect of wing color change on H. melpomene courting and mating behavior. To accomplish this, 26 female and 18 male H. melpomene had the red stripe on their forewing painted. Half of the individuals were painted white, and the other half were painted red as a control. Their mating and courting behavior was observed to see how they were affected by the color change. Over seven days, seven matings were observed – all between red individuals. White males also tried to court red females and were rejected on six different occasions. This demonstrates that decreased reproductive success is an immediate consequence of wing color change and wing color may be responsible for the racial isolation observed in H. melpomene. Because of this strong sexual selection to maintain existing color patterns, geographic isolation is most likely necessary for the evolution of any new mimicry patterns. El color de las alas de las mariposas se usa para señales sociales y para la protección de los depredadores. Las mariposas obtienen protección de los depredadores por tener alas de color que advierten al depredador de que la mariposa es venenosa. Algunas mariposas son parte de los complejos del mimetismo Mullerian en que dos especies venenosas tienen alas muy parecidas para aumentar su protección. Heliconius erato y Heliconius melpomene son mimetismos de Mullerian que demuestran una gran variedad de diseño de alas por todo Centro y Sur América. Sus diseños de ala son muy variadas dentro de cada especie, pero entre las dos especies son casi mímicos perfectos en cada lugar. Se ha encontrado previamente que H. melpomene prefiere cortejar a las mariposas de su misma raza de diseño. Esta investigacion examino una posible razón por este aislamiento racial. Se investigo el efecto de los cambios en el color de las alas de H. melpomene en su apareamiento y cortejo.https://digitalcommons.usf.edu/tropical_ecology/1058/thumbnail.jp