The world’s first amphibious insects have been discovered by scientists.
The tiny caterpillars belong to the moth genus Hyposmocoma which includes an enormously diverse group of at least 350 species found only on Hawaii.
Entomologist Professor Daniel Rubinoff and colleagues observed larvae feeding and breathing in streams and on dry rocks – a newly discovered phenomenon.
Many insects can withstand extreme conditions in a dormant state, but never before has one been known to survive an entire life cycle above and below the water’s surface.
The team sequenced the caterpillars’ genes and say their versatility represent an example of parallel evolution – a rare event in which unrelated organisms develop similar characteristics simply by living in the same place.
And they believe it has occurred three separate times during Hyposmocoma’s history beginning six million years ago before the current islands existed.
Prof Rubinoff, of Hawaii University, said similar patterns of parallel evolution have also been found in damselflies and birds which are unique to the islands.
Four species of Hyposmocoma including molluscivora have been discovered to binds snails with silk webbing before devouring them whole – the first caterpillars known to eat snails or molluscs of any kind.
This behaviour occurs nowhere else on Earth. The overwhelming majority of caterpillars are vegetarians and even the few known predatory groups feed exclusively on insects.
But peculiar adaptations are par for the course in Hawaii – the most remote islands in the world – which also boasts spiders that impale flying insects with their long claws.
Such oddities are probably a result of the islands’ great isolation which means many ecological niches normally exploited by other animals remain vacant. …