The motor output during turning flight in a hawkmoth, Manduca sexta

Changing Motor Patterns of the 3rd Axillary Muscle Activities Associated with Longitudinal Control in Freely Flying Hawkmoths

“…This unit acts as a wing retractor and is activated once or twice during a wingstroke (Kammer, 1971;Rheuben and Kammer, 1987;Wendler et al ., 1993). Kammer (1971) recorded from the 3AXM (the upper unit) during tethered flight of M. sexta , and reported that phase of the 3AXM activities is usually in phase or slightly before the depressor muscle activities (the DLMs and the subalar muscle) while in turning flight, the phase shifts and is in phase or slightly before the DVM activities. During this transition phase, the 3AXM activities are observed twice during a wingstroke.…”

“…The direct muscles attach to base of the wings and move them directly, while the indirect muscles attach to the exoskeleton and move wings by distorting the structure of the thorax (Snodgrass, 1935). In Lepidoptera, the dorsal longitudinal muscles (DLMs, indirect wing depressors) and the dorso-ventral muscles (DVMs, indirect wing elevators) occupy large volume of the thorax (Eaton, 1971) for the basic motion of wing flapping while direct muscles are thin and act in various phases associated with visual stimuli and flight behaviors (Kammer, 1971;Kammer and Nachtigall, 1973;Wendler et al ., 1993). Some direct muscles have identified roles for wing movements such as promotion, retraction, pronation and supination by their attachment to the wing sclerites (Snodgrass, 1935;Kammer, 1967;Rheuben and Kammer, 1987), therefore these direct muscles are regarded as being involved in flight control, especially directional control as steering muscles.…”

“…Some direct muscles have identified roles for wing movements such as promotion, retraction, pronation and supination by their attachment to the wing sclerites (Snodgrass, 1935;Kammer, 1967;Rheuben and Kammer, 1987), therefore these direct muscles are regarded as being involved in flight control, especially directional control as steering muscles. The 3rd axillary muscles (3AXMs = pleurodorsal muscle PD2a, b, c; nomenclature after Eaton, 1971) are well-studied direct flight muscles in tobacco hawkmoths, Manduca sexta (Kammer, 1971;Rheuben and Kammer, 1987;Wendler et al ., 1993). The 3AXMs in the mesothorax consist of three units (upper, middle and lower), are attached to the 3rd axillary sclerite and each unit is innervated by a single motor neuron respectively (Rheuben and Kammer, 1987).…”

“…Since the 3rd axillary sclerite is situated posterior to the base of the wing, contraction of the 3AXMs pulls the wing back along to the body axis (wing retraction). Under the tethered flight of moths, changing phase and bursting of the 3AXM activities and associated asymmetrical wing retraction were observed in relation to the direction of turn that were spontaneous or induced by visual stimulation (Kammer, 1971;Kammer and Nachtigall, 1973;Rheuben and Kammer, 1987;Wendler et al ., 1993). These changes of activities of the 3AXMs and associated wing retractions are also observed in the zigzag walking of non-flying silkmoths (Ariyoshi and Kanzaki, 1996;Kanzaki, 1998).…”

Studies of the Neural Basis of Evasive Flight Behavior in Response to Acoustic Stimulation in Heliothis zea (Lepidoptera: Noctuidae): Motoneuronal Innervation of Flight Muscles

“…The direct and indirect muscles that control fore-and hind wing movements are asynchronous (Pringle 1968;Kammer 1971Kammer , 1985. Like other investigators, we have focused primarily on the indirect muscles because these are involved particularly with deformations of the thorax, such as those performed in evasive flight maneuvers.…”