Takeoff diversity in Diptera

Abstract

The order Diptera (true flies) are named for their two wings because their hindwings have evolved into specialized mechanosensory organs called halteres. Flies use halteres to detect body rotations and maintain stability during flight and other behaviours. The most recently diverged dipteran monophyletic subsection, the Calyptratae, is highly successful, accounting for approximately 12% of dipteran diversity, and includes common families like house flies. These flies move their halteres independently from their wings and oscillate their halteres during walking. Here, we demonstrate that this subsection of flies uses their halteres to stabilize their bodies during takeoff, whereas non-Calyptratae flies do not. We find that flies of the Calyptratae are able to take off more rapidly than non-Calyptratae flies without sacrificing stability. Haltere removal decreased both velocity and stability in the takeoffs of Calyptratae, but not other flies. The loss of takeoff velocity following haltere removal in Calyptratae (but not other flies) is a direct result of a decrease in leg extension speed. A closely related non-Calyptratae species ( D. melanogaster ) also has a rapid takeoff, but takeoff duration and stability are unaffected by haltere removal. Haltere use thus allows for greater speed and stability during fast escapes, but only in the Calyptratae clade.

Stability and manoeuvrability in animal movement: lessons from biology, modelling and robotics

“…Halteres also play a role in maintaining the timing of the wingbeat. In their paper, 'Takeoff diversity in Diptera', Yarger et al [5] show that, in a relatively recent calyptrate branch of Diptera, the flies use their halteres in another way too: when rapidly extending their legs to take off. Calyptrate flies, including house flies and blowflies but not the genetic model species of Drosophila, oscillate their halteres while walking and also use them to control fast take-off behaviour.…”

Scaling of sense organs that control flight: Size and sensory cell number of dipteran fly halteres

“…They participate in a control system that initiates rapid adjustments to visual signals (Chan & Dickinson, 1996; Dickerson et al., 2019; Fayyazuddin & Dickinson, 1996). Besides a role in flight, in some dipterans, they play roles in walking and rapid take‐off (Fraenkel, 1939; Hall et al., 2015; Sandeman & Markl, 1980; Yarger et al., 2021), and some flightless dipterans have motile halteres (Miller, 1977).…”