When cheating pays – survival strategy of insect uncovered

Newswise — Researchers have unveiled a remarkable "cheating" tactic employed by an insect species in New Zealand to evade predation – it mimics the appearance of a highly toxic species.

In the natural world, poisonous creatures typically signal their toxicity through distinctive features, often displaying high contrast colors like black, white, and yellow, similar to wasps and bees.

In a parallel fashion, the cyanide-producing stonefly, Austroperla cyrene, found in New Zealand, uses conspicuous colors of black, white, and yellow as potent "warning" signals to deter potential predators.

In a recent publication in Molecular Ecology, researchers from the University of Otago Department of Zoology disclose a fascinating discovery: an unrelated, non-toxic species employs a deceptive strategy by imitating the appearance of this particular insect.

According to the lead author, Dr. Brodie Foster, the Zelandoperla fenestrata stonefly adopts a strategy of close resemblance to a poisonous species, aiming to escape predation.

In the natural environment, birds find it challenging to discern any dissimilarities between the toxic and non-toxic species, leading them to avoid both.

"As perceptive observers, the poisonous species and its mimics appear almost indistinguishable to the untrained eye," he explains.

The researchers employed genomic techniques to uncover a crucial genetic mutation in a coloration gene that sets apart the cheating individuals from the non-cheating ones.

This genetic variation enables the cheating species to employ diverse strategies in various regions.

However, according to co-author Dr. Graham McCulloch, the strategy, known as Batesian mimicry, does not guarantee success in all cases.

The results of our study reveal that the "cheating" strategy becomes ineffective in regions where the poisonous species is scarce," states co-author Dr. Graham McCulloch.

Co-author Professor Jon Waters adds a cautionary note, stating that cheating can be risky. If the number of cheats begins to surpass that of the poisonous species, predators will swiftly catch on, leading to a delicate balancing act.

The Marsden-funded research team is currently evaluating how environmental changes are provoking rapid evolutionary changes in New Zealand's native species.