Sphingidae Taxonomic Inventory

Creating a taxonomic e-science

Wettability and morphology of proboscises interweave with hawkmoth evolutionary history

Publication Type:Journal Article
Year of Publication:2023
Authors:A. V. Palaoro, Gole, A. R., Y., S., Puchalski, A., Beard, C. E., Adler, P. H., Kornev, K. G.
Journal:Journal of Experimental Biology
Volume:226
Issue:19
Start Page:jeb245699
Pagination:jeb245699
Date Published:10/2023
Keywords:ADULT FEEDING, AGRIUS, CAPILLARY PRESSURE, CONTACT ANGLE, DARAPSA, DOLBA, ENYO, EUMORPHA, FEEDING EFFICIENCY, FLUID DYNAMICS, FLUID-STRUCTURE INTERACTION, HEMARIS, HYLES, MANDUCA, MENISCUS, PARATREA, PROBOSCIS, SPHINGIDAE, XYLOPHANES
Abstract:

Hovering hawkmoths expend significant energy while feeding, which should select for greater feeding efficiency. Although increased feeding efficiency has been implicitly assumed, it has never been assessed. We hypothesized that hawkmoths have proboscises specialized for gathering nectar passively. Using contact angle and capillary pressure to evaluate capillary action of the proboscis, we conducted a comparative analysis of wetting and absorption properties for 13 species of hawkmoths. We showed that all 13 species have a hydrophilic proboscis. In contradistinction, the proboscises of all other tested lepidopteran species have a wetting dichotomy with only the distal ~10% hydrophilic. Longer proboscises are more wettable, suggesting that species of hawkmoths with long proboscises are more efficient at acquiring nectar by the proboscis surface than are species with shorter proboscises. All hawkmoth species also show strong capillary pressures which, together with the feeding behaviors we observed, ensure that nectar will be delivered to the food canal efficiently. The patterns we found suggest that different subfamilies of hawkmoths use different feeding strategies. Our comparative approach reveals that hawkmoths are unique among Lepidoptera and highlights the importance of considering the physical characteristics of the proboscis to understand the evolution and diversification of hawkmoths.

DOI:10.1242/jeb.245699
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith