Editing Halteres (section)

==History==
Halteres were first documented by [[William Derham]] in 1714. He discovered that flies were unable to remain airborne when their halteres were surgically removed, but otherwise behaved normally.<ref>{{cite book|last1=Derham|first1=William|title=haltere|date=1714|publisher=Physico-Theology|location=London}}</ref> This result was initially attributed to the haltere's ability to sense and maintain equilibrium. In 1917 v. Buddenbrock asserted that something else was responsible for the flies' loss of flight ability.<ref name="Budd 1919">{{cite journal|last1=v. Buddenbrock|first1=W|title=haltere|journal=Pflügers Archiv für die gesamte Physiologie|date=1919|volume=175|issue=125}}</ref> He claimed that the halteres should instead be considered "stimulation organs".<ref name="Pringle 1948"/><ref name="Budd 1919"/> In other words, that the activity of the halteres energized the wing muscular system, so that they acted as an on/off switch for flight. V. Buddenbrock attempted to show that activation of the halteres would stimulate the central nervous system into a state of activity which allowed the wings to produce flight behavior.<ref name="Budd 1919"/> It has since been concluded that this is not in fact true, and that the original assertion that halteres act as balance organs is the correct one. V. Buddenbrock was able to show that immediately after haltere removal flies were unable to produce normal wing movements. This was later explained by the fact that allowing flies a few minutes recovery time post-surgery resulted in total recovery of normal flight muscle control. Further, in an interesting side experiment performed by Pringle (1938), when a thread was attached to the abdomen of haltereless flies, relatively stable flight was again achieved.<ref name="Fraenkel 1938"/> The thread in these experiments presumably aided in keeping the fly from rotating (similar to the way a heavy basket below a [[hot air balloon]] prevents the balloon from tipping), which supported the hypothesis that halteres are responsible for sensing body rotations.<ref name="Pringle 1948" />

The original balancer theory, which was postulated by Pringle (1948), only accounted for forces produced in two directions. Pringle claimed that yaw was the only direction of rotation that flies used their halteres to detect. Using high speed video analysis, Faust (1952) demonstrated that this was not the case and that halteres are capable of detecting all three directions of rotation.<ref name="Faust 1952">{{cite journal|last1=Faust|first1=R.|title=Untersuchungen zum halterenproblem|journal=Zool Jahrb Physiol|date=1952|volume=63|pages=352–366}}</ref> In response to this new discovery, Pringle reexamined his previous assumption and came to the conclusion that flies were capable of detecting all three directions of rotation simply by comparing inputs from the left and right sides of the body.<ref name="Pringle 1957">{{cite book |last1=Pringle |first1=J. W. S. |title=Insect Flight |date=1957 |publisher=Cambridge University Press |isbn=978-0-521-13500-9 }}{{pn|date=March 2024}}</ref> Of course, this is not the actual mechanism by which flies detect rotation. Different fields of sensory organs located in different regions at the base of each haltere detect the different directions of rotation, which also explains why flies with one haltere are still able to fly without issue.<ref name="Nalbach 1993"/>