How transparency in butterflies and moths helps ward off predators

[Judi Lynn]

Date:
December 21, 2021
Source:
eLife

Transparent wing patches may do more than allow butterflies and moths to hide -- they may also warn predators to leave them alone, suggests a study published today in eLife.

The findings shed new light on how some butterflies and moths that have partially transparent wings have evolved to mimic other species that already had this feature. They also provide new details on the tiny structures that allow light to pass through the wing.

Despite their delicate look, butterflies and moths have numerous defences. They may use camouflage or transparent patches on their wings to escape a predator's notice, or they may use bright, contrasting colours to warn predators that they are toxic or otherwise unpalatable. These warning colour patterns are so effective at warding off predators that other butterfly and moth species -- even ones without toxic defences -- evolve to mimic them. While transparency usually allows butterflies and moths to escape predators by blending into their surroundings, some species have evolved both transparent patches and vivid warning colours.

"We set out to explore the structural and optical features of transparent patches in various species that also have warning colourations," says first author Charline Pinna, a PhD student at Muséum national d'Histoire naturelle, Sorbonne Université, Paris, France. "By doing so, we hoped to determine how butterflies and moths evolved these defences and how bird predators perceive them."

More:
https://www.sciencedaily.com/releases/2021/12/211221102732.htm

[Judi Lynn]

1. Map of transparent butterflies highlights biodiversity hotspot in the Andes Mountains

Date:
December 16, 2021
Source:
Florida Museum of Natural History

With over a million known species, insects are by far the most diverse group of organisms on Earth, with conservative estimates indicating there are millions more waiting to be found. But extinction due to human pressures may be outpacing the rate of discovery, with species disappearing before researchers even knew they existed.

To conserve these species, scientists must first know where they are. While the distributions of some plant and animal groups have been extensively mapped, comparatively little is known regarding the whereabouts of the world's insects.

In a new study, researchers created the most detailed distribution map to date of butterflies in the American tropics, showing that areas of highest diversity coincide with regions most threatened by deforestation and development. The study specifically focused on Ithomiini, or glasswing butterflies, a large group with nearly 400 species that occur throughout much of Central and South America. Their ubiquity may make them a good indicator for the fate of other insects in the region.

"If we want to understand the diversity of insects in general, then one approach is to concentrate on groups that likely reflect the diversity of all insects and for which we have good knowledge, like butterflies," said study co-author Keith Willmott, curator and director of the Florida Museum of Natural History's McGuire Center for Lepidoptera and Biodiversity.

More:
https://www.sciencedaily.com/releases/2021/12/211216150240.htm