Insects discovered that have to change color because of humans

Researchers have discovered that a native New Zealand stonefly species is forced to change its body colour to survive in heavily deforested areas.

The Zelandoperla long-tailed stonefly once had a clever strategy to avoid bird predation: it mimicked the appearance of its poisonous relative, the Austroperla stonefly . The Austroperla stonefly lives mainly in dense forests and warns off would-be predators by secreting cyanide.

The black Zelandoperla stonefly (centre) camouflages itself like the Austroperla stonefly (left) to avoid predators and evolves a lighter colour (right) to adapt to its new environment - (Photo: University of Otago)

Although not poisonous, the Zelandoperla long-tailed stonefly can mimic the appearance of the Austroperla stonefly quite convincingly using its genetic toolkit, which can make some insects as black as ebony.

This camouflage helps them avoid predatory birds because they cannot distinguish between real poisonous stoneflies and camouflaged non-poisonous stoneflies.

However, recently, a research team from the University of Otago (New Zealand) discovered that Zelandoperla stoneflies in deforested areas have changed to another way to survive.

"Austroperla live in forests, near streams, feeding on leaves and rotting wood. In forests that are destroyed, Austroperla will become less common due to a lack of food sources. To survive, Zelandoperla stoneflies are forced to abandon the Austroperla mimicry strategy and instead evolve a different color ," said zoologist Jon Water.

According to ScienceAlert on November 11, the research team combined field observations, predator experiments and gene mapping analysis to show the response of this insect species to changes caused by humans.

In experiments with different colored models of Zelandoperla, the team found that raptors only attacked uncamouflaged stoneflies in dense forest environments. In degraded forest environments, they were less likely to forage for brightly colored stoneflies than for ebony stoneflies.

This study was published in the journal Science .