Tortoise Beetle (common metallic-striped gold form)

Description:

The tortoise beetle species, Chelymorpha alternans, is a multicolored mystery. Individuals come in five distinct color morphs, including the common metallic-striped gold form (this one) , a brick-red version and three different black and red patterns.

Habitat:

Our garden in Windwardside at the foot of Mount Scenery, the volcano that makes Saba, in the Caribbean Sea, Dutch Caribbean.

Notes:

" Color is super fascinating,” Lynette Strickland said. “In this tortoise beetle species, it's about discovering how color differences might be beneficial by giving them some sort of advantage when it comes to predation, selection, and/or living in different climates." Color figures in the three main rules of survival: eat, avoid getting eaten, make babies. This tortoise beetle nibbles on vines in the morning glory family. But Strickland's first suite of experiments with the beetle morphs tackles the other two topics and has led to some fascinating results. First, to look at predation, Strickland took the five beetle morphs and fed them to common predators — or at least she tried to. The taste-testers delivered the whole gamut of results from total predation to total abstinence. Golden orb-weaving spiders ate (or wrapped in silk and saved for later) all beetles of all color morphs that Strickland threw into their webs. Picky praying mantises, on the other hand, only stabbed at the beetles with their forelegs (which act as taste buds) before rejecting them outright. The most curious results came from colonies of the ant Azteca chartifex, known for their enormous, teardrop-shaped nests. Strickland built platforms at the bottom of nests where the defensive ants swarm over and attack any beetle invader. Since the ants are social creatures that make group decisions, they would initially take up to a couple of hours to decide what to do with the beetles. Ultimately, the golden ones would be thrown off the platform, the red-and-black phenotypes would be consumed, and the ones that were entirely red would be eaten the first three times they were given to the nest, but thrown off the next seven times they were presented with the beetles. "This is pretty indicative of a learned aversion to something," says Strickland. "The point of having bright or conspicuous coloration is to, in theory, send a signal other predators: 'I'm distasteful, don't eat me."