Feeding rate in adult Manduca sexta is unaffected by proboscis submersion depth

• Published in: PloS one Vol. 19; no. 5; p. e0302536
• Main Authors: Pierce, Tomas F., Hedrick, Tyson L.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 29.05.2024; Public Library of Science (PLoS)
• Subjects: Animal Structures - anatomy & histology; Animal Structures - physiology; Animals; Biology and Life Sciences; Butterflies & moths; Cameras; Computer and Information Sciences; Drinking behavior; Engineering and Technology; Feeding; Feeding Behavior - physiology; Feeding rates; Fluid dynamics; Humidity; Localization; Machine learning; Manduca - physiology; Manduca sexta; Nectar; Neural networks; Plant Nectar; Proboscis; Software; Submergence
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0302536

Adult moths from framily Spingidae (i.e. hawkmoths or sphinx moths) commonly feed on flower nectar through an extended proboscis, often several centimeters in length and longer than the body of the moth. Feeding on a viscous liquid (nectar) through a long and narrow tube is a challenging fluid dynamic problem and the subject of long-running scientific investigation. Here we characterized the relationship between proboscis submergence depth and nectar drinking rate in Manduca sexta hawkmoths. Video recordings of moth feeding bouts were collected and neural networks were used to extract data by object localization, tracking the location of the nectar meniscus and moths’ proboscis tips. We found that although feeding rates vary among bouts, the variation was not associated with proboscis submergence depth. These results show that despite the theoretical possibility of fluid uptake through the walls of the proboscis, such effects do not have a substantial effect on nectar uptake rate, and suggest that nectar must traverse the full length of the proboscis.