Anatomy of an agricultural antagonist: Feeding complex structure and function of three xylem sap-feeding insects illuminated with synchrotron-based 3D imaging

Authors: CLARK, ELIZABETH - University Of California Berkeley; CORNARA, DANIELE - University Of Bari; BRODERSEN, CRAIG - Yale University; McElrone, Andrew; PARKINSON, DILWORTH - Lawrence Berkeley National Laboratory; ALMEIDA, RODRIGO P - University Of California Berkeley

Submitted to: Journal of Morphology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/2023
Publication Date: 9/3/2023
Citation: Clark, E.G., Cornara, D., Brodersen, C.R., McElrone, A.J., Parkinson, D.Y., Almeida, R.P. 2023. Anatomy of an agricultural antagonist: Feeding complex structure and function of three xylem sap-feeding insects illuminated with synchrotron-based 3D imaging. Journal of Morphology. 284:e21639. https://doi.org/10.1002/jmor.21639.
DOI: https://doi.org/10.1002/jmor.21639

Interpretive Summary:

Technical Abstract: Many insects are known to feed on xylem or phloem sap within the vascular tissue of plants. Although physical damage to the plant is minimal, the insects employing this strategy can vector lethal viruses and bacterial pathogens to plants over the process of feeding. Disparities between disease transmission efficiency have been identified within xylem sap-feeding insects; however, it is unclear what drives these. Identifying and understanding the morphological factors and associated integrated functional components that underly these disparities is critical for managing their consequences. However, the mechanics underlying basic elements of xylem sap ingestion remain poorly understood. This is due, in part, to a limited understanding of the functional anatomy of these insects. Here, we applied synchrotron-based microcomputed tomography to digitally reconstruct the morphology of three xylem sap-feeding leafhopper vectors of plant pathogens: Graphocephala atropunctata (blue-green sharpshooter), Homalodisca vitripennis (glassy-winged sharpshooter), and Philaenus spumarius (meadow spittlebug), in three dimensions. The application of this technique revealed previously undescribed anatomical features of these organism, such as key components of the salivary complex and the structure of the precibarial valve, and highlighted aspects of morphological disparities between taxa that likely have functional consequences. For example, we found that the volume of the cibarial musculature of H. vitripennis, exceeds that of the other two insects by over threefold and is larger both in terms of absolute size and relative size to the rest of the feeding complex. These morphological insights will be used to target analyses illuminating functional differences in feeding behavior.