Some Insects Change Their Appearance to Appear Poisonous and Escape Predators

Austroperla cyrene

Have you ever found yourself mixing up the false coral snake and the coral snake? If you have, you’ve inadvertently fallen into the snare of Batesian mimicry—an evolutionary tactic observed in harmless species. This strategy involves adopting the visual pattern and colors, commonly recognized as “cautionary,” from their harmful counterparts. This allows the innocuous creatures to elude predators that steer clear of them.

This phenomenon has recently been discerned in Zelandoperla, a diminutive see-through midge renowned as the “pearl” or “stonefly.” Within the widespread population of this stonefly across New Zealand, a small number of individuals have been identified. These individuals exhibit yellow legs and a black body reminiscent of a toxic insect, Austroperla cyrene, which generates cyanide.

A Rare Mutation Within the Same Species

Zelandoperla fenestrata
Zelandoperla fenestrata. Image: iNaturalist NZ.

Primarily, and particularly due to its widespread occurrence, the phenomenon of mimicry stands as a noteworthy subject. Consider our example of the deceptive coral snake, where every member of the species showcases a splendid color scheme akin to that of the genuine coral snake. Nevertheless, how do we make sense of the variation found within the same species? As indicated by the researchers who presented their findings in the Molecular Ecology publication, the key concept can be succinctly captured in one term: melanin.

The insects that underwent changes in appearance were exclusively those possessing elevated levels of melanin. Consequently, they garnered more attention from predators, leading to a more pronounced selective presence. Thus, individuals expressing the gene responsible for melanism—this mutation imparts a black hue to certain species—have notably improved odds of survival, particularly in regions teeming with Austroperla cyrene. The scientists view this as a sophisticated strategy for survival, underscoring the enduring significance of specific genes in the insect realm.