Biomechanics. Mechanistic origins of bombardier beetle (Brachinini) explosion-induced defensive spray pulsation.
Bombardier beetles (Brachinini) use a rapid series of discrete explosions inside their pygidial gland reaction chambers to produce a hot, pulsed, quinone-based defensive spray. The mechanism of brachinines' spray pulsation was explored using anatomical studies and direct observation of explosions inside living beetles using synchrotron x-ray imaging. Quantification of the dynamics of vapor inside the reaction chamber indicates that spray pulsation is controlled by specialized, contiguous cuticular structures located at the junction between the reservoir (reactant) and reaction chambers. Kinematics models suggest passive mediation of spray pulsation by mechanical feedback from the explosion, causing displacement of these structures.
Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139-4307, USA.
Eric M
EM
Arndt
Department of Entomology, The University of Arizona, Tucson, AZ 85721-0036, USA.
Wendy
W
Moore
National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973-5000, USA.
Wah-Keat
WK
Lee
Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139-4307, USA. cortiz@mit.edu.
Christine
C
Ortiz
D000818:Animals; D016227:Benzoquinones / Q000737:chemistry; D005075:Biological Evolution; D001696:Biomechanical Phenomena; D001517:Coleoptera / Q000033:anatomy & histology / Q000737:chemistry / Q000502:physiology*; D005088:Exocrine Glands / Q000033:anatomy & histology / Q000378:metabolism; D009132:Muscles / Q000502:physiology*; D017356:Synchrotrons
D016227:Benzoquinones; C004532:quinone