Quantification and analysis of ecdysis in the hornworm, Manduca sexta, using machine vision-based tracking

Area of Science:

• Animal behavior research
• Machine vision applications
• Insect physiology

Background:

• Ecdysis, or molting, is a critical developmental process in insects.
• Monitoring ecdysis behaviors in insects like Manduca sexta (hornworm) can provide insights into physiological processes.
• Accurate and automated tracking of physical deformations during ecdysis is challenging.

Purpose of the Study:

• To develop and validate a machine vision-based method for automated tracking of body wall deformations during Manduca sexta ecdysis.
• To assess the accuracy and robustness of the developed tracking system.
• To compare in vivo ecdysis motor patterns with fictive motor patterns.

Main Methods:

• Development of a machine vision system utilizing naturally occurring features (spiracles) for tracking.
• Implementation of electromyography to record muscle activity during ecdysis.
• Comparison of in vivo ecdysis data with fictive motor patterns from isolated nerve cords.

Main Results:

• The machine vision method achieved >95% accuracy in tracking body wall deformations.
• The tracking system demonstrated robustness to changes in animal position and lighting conditions.
• No significant difference was found in contraction cycle periods between naturally occurring and prematurely induced ecdysis, nor between in vivo and fictive motor patterns.

Conclusions:

• The developed machine vision system provides an accurate and robust tool for monitoring ecdysis behaviors in Manduca sexta.
• The study confirms the similarity of motor patterns during natural and induced ecdysis, supporting the validity of fictive motor pattern analysis.