Biology subjects

Deora, T.

Publications and source records attributed to Deora, T..

5 recordsLinked to original sources

bioRxiv2026

Pilifers provide rapid mechanosensory feedback during floral tracking in hawkmoths

Hawkmoths expertly hover over flowers during feeding, accurately tracking floral movements even as flowers gently sway in the wind. They use visual and mechanosensory feedback to adjust their position, while their long, flexible mouthpart, the proboscis, stays inserted inside the nectar spur. Although much is known about how hawkmoths detect and process visual motion, far less is understood about how hawkmoths detect mechanical motion cues. Pilifers are hair bundles at the proboscis-head joint, well-positioned to provide feedback about floral motion. Here, we tested if pilifers could provide mechanosensory feedback essential for successful floral tracking. We computed bending at the proboscis base during floral tracking in freely flying hawkmoths and found that floral movements induce small yet significantly correlated lateral bending. Recordings from pilifer afferents showed that they respond to lateral motions of amplitudes similar to those seen in natural floral tracking behaviors. They respond to different directions and speeds of proboscis motion with an average latency of 1.9 ms. Neural tracing revealed extensive sensory arborizations in the sub-esophageal ganglion of the brain and ventral nerve cord, indicating a feedback pathway to the neck and flight motor system that enables rapid coordination of appendages and body for successful feeding.

neuroscience↗

bioRxiv2023

Intraspecific variation in the placement of campaniform sensilla on the wings of the hawkmoth Manduca sexta

Flight control requires active sensory feedback, and insects have many sensors that help them estimate their current locomotor state, including campaniform sensilla, which are mechanoreceptors that sense strain resulting from deformation of the cuticle. Campaniform sensilla on the wing detect bending and torsional forces encountered during flight, providing input to the flight feedback control system. During flight, wings experience complex spatio-temporal strain patterns. Because campaniform sensilla detect only local strain, their placement on the wing is presumably critical for determining the overall representation of wing deformation; however, how these sensilla are distributed across wings is largely unknown. Here, we test the hypothesis that campaniform sensilla are found in stereotyped locations across individuals of Manduca sexta, a hawkmoth. We found that although campaniform sensilla are consistently found on the same veins or in the same regions of the wings, their total number and distribution can vary extensively. This suggests that there is some robustness to variation in sensory feedback in the insect flight control system. The regions where campaniform sensilla are consistently found provide clues to their functional roles, although some patterns might be reflective of developmental processes. Collectively, our results on intraspecific variation in campaniform sensilla placement on insect wings will help reshape our thinking on the utility of mechanosensory feedback for insect flight control and guide further experimental and comparative studies.

neuroscience↗

bioRxiv2022

Abdominal movements in insect flight reshape the role of non-aerodynamic structures for flight maneuverability I: Model predictive control for flower tracking

Research on insect flight control has focused primarily on the role of wings. Yet abdominal deflections during flight can potentially influence the dynamics of flight. This paper assesses the role of airframe deformations in flight, and asks to what extent the abdomen contributes to flight maneuverability. To address this, we use a combination of both a Model Predictive Control (MPC)-inspired computational inertial dynamics model, and free flight experiments in the hawkmoth, Manduca sexta. We explored both underactuated (i.e. number of outputs are greater than the number of inputs) and fully actuated (equal number of outputs and inputs) systems. Using metrics such as the non-dimensionalized tracking error and cost of transport to evaluate flight performance of the inertial dynamics model, we show that fully actuated simulations minimized the tracking error and cost of transport. Additionally, we tested the effect of restricted abdomen movement on free flight in live hawkmoths by fixing a carbon fiber rod over the thoracic-abdomen joint. Moths with a restricted abdomen performed worse than sham treatment moths. This study finds that abdominal motions contribute to flight control and maneuverability. Such motions of non-aerodynamic structures, found in all flying taxa, can inform the development of multi-actuated micro air vehicles.

physiology↗

bioRxiv2020

Tactile active sensing in insect-plant pollination

The interaction between insects and the flowers they pollinate has driven the evolutionary diversity of both insects and flowering plants, two groups with the most numerous species on earth. Insects use vision and olfaction to localize their host plants, but to feed from the flower, they must find the tiny nectary opening, which can be well beyond their visual resolution. When vision is limited, the sense of touch becomes especially crucial, yet very few studies have investigated the role of rapid and precise tactile feedback in successful feeding and pollination interactions. In this paper, we study the remarkable feeding behavior of flying insects that use their proboscis, a flexible mouthpart often longer than their entire body length when unfurled, to expertly explore floral surfaces. Specifically, we observed how the crepuscular hawkmoth Manduca sexta interacts with artificial, 3D-printed flowers of varying shapes. We found that moths actively explore the flower for tactile features, systematically sweeping their proboscis from edge to center repeatedly until they locate the nectary. Moreover, naive moths rapidly learn to exploit flowers, and they adopt a tactile search strategy to more directly locate the nectary in as few as three to five consecutive visits. We suggest moths wield their proboscis to extract salient tactile features, such as floral edges and corolla curvature. Our results highlight the proboscis as a unique sensory structure and emphasize the central role of touch in insect-plant pollination interactions.

neuroscience↗

bioRxiv2020

The coupled dual-oscillator model of wing and haltere motion in flies

The mechanics of Dipteran thorax is dictated by a network of exoskeletal linkages which, when deformed by flight muscles, generate coordinated wing movements. In Diptera, forewings power flight, whereas hindwings have evolved into specialized halteres which provide rapid mechanosensory feedback for flight stabilization. Although actuated by independent muscles, wing-haltere motion is precisely phase-coordinated at high frequencies. Because wingbeat frequency is a product of wing-thorax resonance, wear-and-tear of wings or thorax should impair flight ability. Here, we show that wings and halteres are independently-driven, linked, coupled oscillators. We systematically reduced wing length in flies and observed how wing-haltere synchronization was affected. The wing-wing system is a strongly-coupled oscillator, whereas wing-haltere system is weakly-coupled through mechanical linkages which synchronize phase and frequency. Wing-haltere link is unidirectional; altering wingbeat frequency affects haltere frequency, but not vice-versa. Exoskeletal linkages are thus key morphological features of Dipteran thorax, ensuring robust wing-haltere synchrony despite wing damage.

evolutionary biology↗