Wing flexibility of cicadas during takeoff A pandemic story


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


66-12  Sat Jan 2  Wing flexibility of cicadas during takeoff: A pandemic story Socha, JJ*; Pulliam, JN; Salcedo, MK; Hernandez, AM; Weiss, TM; Jackson, BE; Virginia Tech; Virginia Tech; Virginia Tech; Harvard University; Virginia Tech; Longwood University jjsocha@vt.edu http://www.thesochalab.org

Insect wings can be considered as flat plates, but in flight, wings often deform. The role of wing flexibility in insect flight is becoming increasingly appreciated, but a comprehensive understanding of flexibility is lacking. This project examines flexibility in the wings of cicadas during takeoff flight, and also explores its morphological underpinnings. Two external factors conspired to drive this project: the COVID pandemic that restricted access to indoor lab work, and the emergence of Brood IX cicadas in the region around southwest Virginia in May-July 2020. We recorded takeoff flights in a make-shift field site at the home of one of the authors (JJS), examining both male and female cicadas (Magicicada septendecim). Flight trials were recorded using three synchronized high-speed videocameras (Photron Mini UX100 and APS-RX) at a frame rate of 2,000 fps, focused on a volume of interest of ~15 cubic cm. The system was calibrated using a small custom wand (length, 6.60 cm). Flying cicadas exhibited wing flexibility in two regions: 1) between the fore- and hind- wings, and 2) in the tip of the forewing. Forewing flexibility appeared to be enabled by a functional hinge, composed of wing veins, wing membrane, and multiple discontinuities in the veins. Scanning electron micrography of the forewing revealed that these discontinuities consisted of veins tapering to an end, providing a region for flexure. In future work, wing shape and body position throughout the wingbeat cycle will be determined from three-dimensional coordinates of the wing, extracted using DeepLabCut software. This kinematic data will be incorporated into an existing computational fluid dynamics model of cicada flight to probe the influence of wing flexibility on flight performance in insects.

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