In partial fulfillment of the requirements for the degree of

Doctor of Philosophy in Quantitative Biosciences

In the

School of Physics

Leo Wood

Will defend his dissertation

Temporal Precision and Neural Constraints in the Hawkmoth Flight Motor System

Tuesday August 19th, 2025

At 9:30am EDT

 Thesis Advisor:

Simon Sponberg, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Committee Members:

Young-Hui Chang, Ph.D.

School of Biological Sciences

Georgia Institute of Technology

Hannah Choi, Ph.D.

School of Mathematics

Georgia Institute of Technology

Jeffrey Markowitz, Ph.D.

Dept. of Biomedical Engineering
Georgia Institute of Technology

Bradley H. Dickerson, Ph.D.

Princeton Neuroscience Institute

ABSTRACT: Flying insects achieve remarkable feats (70 km/hr flight speeds, navigating multi-day migrations, and executing precise aerial maneuvers) despite operating under extreme neural and mechanical constraints. With brains containing only thousands to millions of neurons, insects must transform diverse sensory information into coordinated motor programs that control flight muscles with sub-millisecond precision at frequencies up to hundreds of times per second. This thesis investigates how large synchronous insects, particularly hawkmoths such as Manduca sexta, achieve agile, robust flight despite severe physiological constraints such as limited neural bandwidth between the brain and body, and the need for millisecond-scale precision in motor output. To that end, we address four critical unknowns: (1) The functional significance of motor precision and coordination in individual muscles, (2) The spatial and temporal bottlenecks imposed by the neck connective, (3) The temporal precision of motor information in descending neurons, and (4) How motor control strategies scale across wingbeat frequencies in different species. Through techniques such as precise motor program manipulation, the first complete nanometer-scale reconstruction of the hawkmoth neck connective, simultaneous multielectrode recordings of descending neurons and the motor program, and comparative analysis across 13 species spanning a 7-fold wingbeat frequency range, this work reveals fundamental principles governing how neural constraints shape the architecture and precision of flight control across scales. The findings demonstrate that temporal precision and coordination are not merely correlated features but functionally interdependent aspects of motor control, with implications for understanding how biological systems achieve complex behaviors under severe computational and physical constraints.