Original paper
Functional morphology of the mesothoracic flight apparatus of Apis mellifera (Hymenoptera: Apidae)
Pfau, Hans Klaus
Entomologia Generalis Volume 37 Number 3-4 (2018), p. 353 - 373
published: Aug 10, 2018
manuscript accepted: Jan 18, 2018
manuscript received: Dec 28, 2017
DOI: 10.1127/entomologia/2018/0652
ArtNo. ESP146003703007, Price: 23.10 €
Abstract
The wingstroke mechanism of Apis mellifera constitutes a synthoracic kinematic chain mechanism, which is convergent with the superficially similar mechanism of Calliphora erythrocephala. A strongly modified tergal arching mechanism is characterized by the fact that frontally and caudally of the marginal tergal incision situated sections of the tergum cooperate in an optimized levering of the wing via the axillary 1 and (stalked) axillary 2. Both possible types of wingstroke-bistability (parascutal and symmetrical click mechanism) are lacking. Specific relative movements between axillary 1 and axillary 2 – considered responsible for “automatic” pronation and supination movements at the turning points of the wingstroke – are not possible because of the presence of a transverse hinge joint between axillary 1-base and axillary 2+axillary 1-hook. Whereas the basalar system is able to extend the wing into the flight position and to flatten the stroke plane during the downstroke (without downstroke or pronation function), the axillary 3-system combines the four functions upstroke, pronation, stroke plane flattening and wing-flexion. Different parts (foremost the axillary lever, axillary 3, axillary 4 and subalare) are integrated in a complicated system for the adjustment of the angle of attack of the wing via the alteration of a Z-profile: at the upper turning point of the wingstroke a fast reduction of the Z (pronation) by the axillary lever-muscle is postulated, whereas the aerodynamical angle of attack is adjustable separately during up and downstroke by muscles of the axillary 3 and subalare.
Keywords
skeleto-muscular systems • mechanics • wing articulation • movement adjustment • pronation • supination