Sound vs. light: wing-based communication in Carboniferous insects

Area of Science:

• Paleontology
• Insect Behavior
• Evolutionary Biology

Background:

• Acoustic communication in insects is known from the Mesozoic era, but evidence from earlier periods is scarce.
• The extinct insect order Titanoptera, from the Permian-Triassic, possesses specialized forewing structures previously hypothesized as resonators for stridulation.

Purpose of the Study:

• To re-evaluate the function of specialized forewing structures in Titanoptera.
• To investigate the possibility of Paleozoic insect communication beyond stridulation.
• To establish the earliest known instance of wing-based communication in insects.

Main Methods:

• Comparative analysis of Titanoptera forewing structures with extant insects (locusts, flies) and fossil damselflies.
• Morphological examination to assess the presence of a stridulatory apparatus (file and scraper).
• Paleontological analysis to date and describe newly discovered Carboniferous Titanoptera specimens.

Main Results:

• Titanoptera specimens lack the necessary structures (stridulatory file) to support the stridulation hypothesis.
• Broadened forewing zones in Titanoptera show similarities to structures used for light flashes or crepitation in other insects.
• Discovery of the oldest Carboniferous Titanoptera specimen (~310 Mya) with these specialized wing zones, predating previously known insect wing communication.

Conclusions:

• The specialized forewing structures in Titanoptera were likely used for producing light flashes and/or crepitated sounds, not stridulation.
• This finding represents the oldest evidence of wing-based communication in insects, pushing back the timeline significantly.
• The precise function (sexual signaling or predator avoidance) of this wing communication in Titanoptera requires further investigation.