This week’s What’s on the van? comes from Zhengyang Wang, an undergraduate volunteer in our Hope Entomology Collection
Belonging to the genus of Heliconius, this species of butterfly can be seen from Southern Mexico to north-central Bolivia, from dense forests to open savannah. Like many other species of this genus, Heliconius hecale has many different forms of a single species. The picture illustrates the form felix of this species, which is commonly found in Munchai, Rio Beni and Bolivia.
In one of the cabinets of the Hope Entomology Collection here at the Museum, you can find another form of the same species but of slightly different wing pattern, vestustus, usually found in Columbia. Sometimes the visual differences between forms of the same species can be quite stark: the fornarina form of Heliconius hecale from Guatemala, for example, is only black and white.
In fact, morphological differences within species is quite common among butterflies. As well as sexual dimorphism, where male and female body shapes differ, species found at different localities, different climates, and in different seasons can also exhibit variations in morphology.
Speaking of morphology, it also needs to be mentioned that many other species from different sub-families of brush-foot butterflies, such as Danaini and Ithomiini, mimic the morphology of these Heliconius butterflies. Why is that? It’s because many Heliconius butterflies are quite unpalatable to their predators, so a mimicry of them might tell predators “Don’t eat me, I’m poisonous.” This kind of mimicry of other species’ warning signals is called Mullerian mimicry.
Thanks to their choice of plant food, their differing wing patterns and the relative ease with which they can be monitored, the butterflies from the genus of Heliconius have also been widely studied to understand genetic evolution and co-evolution between butterflies and plants.
Zhengyang Wang, visiting student at Hertford College, Oxford and volunteer in the Hope Entomological Collection