A long-standing question about periodical cicadas that emerge every 13 or 17 years was recently answered by a team at USDA Agricultural Research Service: Once periodical cicadas emerge, do they really feed on plants? Their analysis of cicadas gut contents found plant DNA in mature adult cicadas however none in freshly emerged adults, a strong indication that adult cicadas do eat plants, since no plant matter in cicadas guts rollovers from their nymph stage. Shown here is a Brood X 17-year cicada grownup on a linden tree leaf in Maryland throughout the broods 2021 introduction. Credit: Peggy Greb, USDA-ARS
Analysis of Brood X cicadas gut contents finds plant DNA, settling long-standing clinical debate.
The periodical cicadas in the genus Magicicada come every 13 or 17 years, though other types of cicadas emerge much more often in our areas. Merely: Once periodical cicadas emerge, do they really feed on plants?
Magicicada pose a hazard to U.S. farming due to their capability to harm orchard trees when they lay their eggs on tree branches. Lots of growers and nurseries take this into factor to consider and avoid planting brand-new trees in years when periodical cicadas emerge, as their eggs can kill young trees.
An enduring query about periodical cicadas that emerge every 13 or 17 years was just recently responded to by a team at USDA Agricultural Research Service: Once periodical cicadas emerge, do they in fact feed on greenery? Their analysis of cicadas gut contents found plant DNA in mature adult cicadas but none in newly emerged adults, a strong sign that adult cicadas do feed on plants, because no plant matter in cicadas guts brings over from their nymph phase. Revealed here is a Brood X 17-year cicada grownup on a linden tree leaf in Maryland during the broods 2021 introduction. The periodical cicadas in the genus Magicicada come every 13 or 17 years, though other types of cicadas emerge much more often in our areas. Simply: Once periodical cicadas emerge, do they actually feed on greenery?
A Century-Old Debate and Recent Discoveries
ARS researchers investigated the finest way to solve this agricultural obstacle by reviewing the biography, reproductive biology, and evolutionary relationships of cicadas over the past 150 years. But many have actually often disagreed about whether, or just how much, the adults feed. This is due to the fact that the needle-like mouthparts of cicadas do not leave much evidence of any feeding, unlike chewing insects, and their digestive systems that are infamously hard to dissect. USDA-ARS scientists studied adult male and female Magicicada during the 2021 introduction of Brood X in Maryland, Virginia, and West Virginia as the insect moved through apple orchards and wooded public parks and homes.
The findings, released October 18 in the Entomological Society of Americas open-access Journal of Insect Science, interrupted the age-old popular myth of adult periodical cicadas not feeding. Scientists found primarily woody plant and Malus, or apple tree DNA, in adult cicada guts and discovered that 54 percent of those cicadas contained DNA from several plant species.
Unwinding the Cicada Diet
While this strongly implies that adult Magicicada feed on plant sap, it was needed to show that the recovered plant DNA was not just leftovers from meals consumed during the nymph stage.
” We evaluated teneral grownups, or brand brand-new adult Magicicada that had actually not had a possibility to feed yet, to examine for any leftover plant DNA,” said USDA-ARS research study team leader James Hepler, Ph.D. “We could not discover any plant DNA in the guts of teneral grownups, so we can be fairly sure that the DNA discovered in fully grown adult Magicicada was consumed throughout the adult stage, because no DNA rollovers from the nymph stage.”
Cicadas appear to have highly permeable exoskeletons that permit considerable water loss and permit water to evaporate out of the pest a little simpler than numerous other pests. Also, the existence of vital amino acid-producing endosymbionts in the gut tissues of adult Magicicada imply that, despite the water loss, some nutrition is being obtained as they eat plant types.
Looking Ahead
USDA-ARS will continue to take a look at the life cycle of Brood X and solve agricultural challenges straight related to their life expectancy above ground. More research studies will likewise be performed to look at the impact that adult Magicicada add to tree physiology.
Recommendation: “Do adult Magicicada (Hemiptera: Cicadidae) feed? Historic point of views and proof from molecular gut content analysis” by James R Hepler, W Rodney Cooper, John P Cullum, Chris Dardick, Liam Dardick, Laura J Nixon, Derek J Pouchnik, Michael J Raupp, Paula Shrewsbury and Tracy C Leskey, 18 October 2023, Journal of Insect Science.DOI: 10.1093/ jisesa/iead082.