Author ORCID Identifier
0009-0003-5858-8249
Biosketch
I am a trained biologist specializing in insect neuroethology, with a focus on sensory-motor integration in insect behavior, encompassing both innate and goal-oriented actions. I am also passionate about science communication, having actively engaged in and organized outreach programs during my PhD to promote awareness of basic science research.
Date of Award
22-5-2025
Document Type
Thesis
School
School of Chemical & Biotechnology
Programme
Ph.D.-Doctoral of Philosophy
First Advisor
Prof.Sanjay.P.Sane
Second Advisor
Dr.Pankaj Yadav
Keywords
Cephalic Mechanosensory Bristles, Airpulse, Warm-Up, Reflexes, Neuroanatomy, Electromyogram
Abstract
During flight, insects sense air movement past their bodies via sensory bristles distributed all over their body. These bristles provide mechanosensory feedback to their nervous system, thereby modulating wing motion to cope with ambient wind conditions. In many insect systems including locusts, moths, etc., flight can be rapidly initiated by stimulating a set of bristles called cephalic bristles on their head. Rapid initiation of flight requires diverse, distributed flight-related reflexes to be simultaneously activated.
Thus, we hypothesized that cephalic bristles directly and simultaneously trigger diverse flight-related reflexes. We tested this hypothesis using the Oleander hawkmoth, Daphnis nerii, as our study system. Our experiments revealed diverse facets of cephalic mechanosensor-mediated flight initiation in tethered hawkmoths. First, at the behavioural level, we observed that moths stimulated with an air puff directed at their head, displayed a robust, rapid flight initiation response.
Such flight initiation activated multiple reflexes including leg extension, wing initiation, antennal positioning, head stabilization, and abdominal flexion. Large moths such as Daphnis nerii , typically require flight muscles to be warmed through a prolonged low amplitude wing motion during voluntary flight. However, thermograms of the thorax of cephalic bristle stimulated moths showed that this warm-up phase was not required for cephalic bristle mediated flight.
Our neuroanatomical studies showed that the primary neurons of these mechanosensors project from the brain into the metathoracic ganglion, arborizing in the region of flight motor neurons. Finally, electromyograms of the steering muscles innervated by flight motor neurons showed consistent activity upon stimulation of cephalic bristles. Thus, air puff activation causes cephalic bristle afferents to activate flight activating a series of interconnected flight-related reflexes.
Recommended Citation
Manjunath, Maitri Ms, "The Role of Cephalic Mechanosensory Bristles in Flight Initiation of the Oleander Hawkmoth, Daphnis nerii" (2025). Theses and Dissertations. 185.
https://knowledgeconnect.sastra.edu/theses/185