Magnusantenna wuae, literally meaning “large antenna”, has the biggest and fanciest antennae of any other known species of Coreidae, and although they make the bug stand out, they may have also been its downfall.

"With the development of angiosperms [flowering plants], sufficient food resources provide the possibility for the nymph to develop such large antennae," Huang said. "Since the Cretaceous, the prosperity of angiosperms has promoted the rise of herbivorous and carnivorous insects, birds and so on, which limited the survival resources of the nymph and increased the number of predators. In addition, the large appendages probably made it move slowly, which would have been a disadvantage when fleeing a predator."

Its extreme antennae are 12 times the size of its head, about as long as its total body length, with four segments ending in huge (for this bug, at least) petal-shaped flaps. The specimen trapped in this amber tomb is a juvenile insect, known as a nymph, but the researchers hypothesize that these enlarged antennae would carry on into adulthood and be used as displays in mating behavior.

"The large and delicate antenna can promote long-distance chemical communication, reduce the risk of predation, and even may play a role in sexual display, thereby enhancing the adaptability to the environment," Huang said.

The development of prominent antennae as a characteristic is little known in ancient insect species as not many are encased in amber for our perusal. But, expanded antennae have evolved many times in different insect groups, usually in males, and are a common characteristic of displaying sexual fitness – much like impressive antlers of stags.

Interestingly, the researchers also suggest the expansive feelers may have had a large number of olfactory receptors that would have made M. wuae particularly good at locating females over long distances. This, you would think, would make them prime candidates for survival, but the researchers point out the large appendages may have made them more visible to predators too.

The obvious argument against the antenna being used for sexual display is that they appear to be fully formed in the juvenile already. However, the researches are also hedging their bets that the unusual appendages could have been used as a defense against predators too.

Camouflage is common in insects – whether it’s mimicking bark, fading into foliage or looking like something else entirely. Misdirection is a more unusual defense mechanism, but it is still found in the animal kingdom, when a particular part of a creature’s body is designed to attract the attention of a predator, so as to protect the more vital parts. The researchers suggest these leaf-like flaps may have been used just for that, and that is why they are so far away from the bug’s body.

Their shape and lack of bright pigment could also mean it was a leaf-mimic, using its petal or leaf-shaped flaps to disguise itself as part of the scenery. Without more examples, we may never know why this tiny bug developed such a far-out set of feelers.

—IFL SCIENCE—