|Cooper, Rodney - William|
|Dardick, Christopher - Chris|
|NIXON, LAURA - US Department Of Agriculture (USDA)|
|POUCHNIK, DEREK - Washington State University|
|RAUPP, MICHAEL - University Of Maryland|
|SHREWSBURY, PAULA - University Of Maryland|
Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2023
Publication Date: 10/18/2023
Citation: Hepler, J.R., Cooper, W.R., Cullum, J.P., Dardick, C.D., Dardick, L.C., Nixon, L., Pouchnik, D.J., Raupp, M., Shrewsbury, P., Leskey, T.C. 2023. Do adult Magicicada (Hemiptera: Cicadidae)feed? Historical perspectives and evidence from molecular gut content analysis. Journal of Insect Science. 23(5):13;1-9. https://doi.org/10.1093/jisesa/iead082.
Interpretive Summary: Periodical cicada adults emerge every 13 or 17 years in tremendous numbers, with many emergences receiving much public and scientific attention. However, there is surprising uncertainty about whether cicada adults feed. The scientific literature is divided and somewhat ambiguous, though the perception that adults do not feed at all persists among the general public. Here we look for direct evidence of feeding behavior in periodical cicadas using gut content analysis. We sequenced and identified plant DNA from the guts of nymphal and adult periodical cicadas from the 2021 emergence of Brood X in the Mid-Atlantic, providing a clear indication that the adult stage ingests plant material. Our findings help resolve a scientific debate that has persisted for over a century and advance our knowledge of the biology of a charismatic insect.
Technical Abstract: The periodical cicadas in the genus Magicicada are remarkable for their unusual life histories and dramatic synchronized emergences every 13 or 17 years. While aspects of their evolution, mating behaviors, and general biology have been well-characterized, there is surprising uncertainty surrounding the feeding habits of the short-lived adult stage. Despite a tentative scientific consensus to the contrary, the perception that adult Magicicada do not feed has persisted among the general public, and recent studies are lacking. We directly investigated the feeding behavior of Magicicada spp. through high-throughput sequencing (HTS)-based dietary analysis of nymphs, freshly molted (teneral) adults, and fully sclerotized adults collected from orchard and wooded habitats during the 2021 emergence of Brood X. Identifiable plant DNA (trnF, ITS amplicons) was successfully recovered from nymphs and adults. No plant DNA was recovered from teneral adults, suggesting that all DNA recovered from sclerotized adults was ingested during the post-teneral adult stage. Both nymphs and adults were found to have ingested a range of woody and herbaceous plants across 17 genera and 14 families. Significantly more plant genera per individual were recovered from adults than from nymphs, likely reflecting the greater mobility of the adult stage. We hypothesize that the demonstrated ingestion of plant sap by Magicicada adults is driven by a need to replace lost water and support specialized bacteriome-dwelling endosymbionts that cicadas depend upon for growth and development, which constitutes true feeding behavior.