Ants prey on cicada hatchlings

Temperate-zone cicadas are characterised among insects by their long-lived underground nymphal stages, which live for 5–20 years or more. Here we report the extensive occurrence of above-ground predation on eggs and first-instar nymphs of the common Japanese brown cicada, Graptopsaltria nigrofuscata, by colonial ants in a city park. Predation on eggs and first-instar nymphs by ants may be a major source of above-ground mortality rate in a population of this Japanese cicada species.

Methods
Newly hatched cicada nymphs (Hayashi & Saisho, 2015) of the most common brown-winged Japanese cicada, Graptopsaltria nigrofuscata, were studied. The observation site comprised three trees in Miyazaki 3rd Park, Miyamae-ku, Kawasaki, Japan (35.591329/139.590882), a typical small city park with planted trees. All three planted trees were a Japanese endemic species of conifer known as Sawara cypress, Chamaecyparis pisifera (Siebold et Zucc.) Endl. (Cupressales: Cupressaceae). The observation period was from June 7 to September 8, 2022 and from April 30 to October 4, 2023 for eggs and nymphs and from August 7 to August 17, 2023 for oviposition and hole-digging behavior. Cicada eggs were suspected to belong to the same species because of the rarity of occurrence of other species within the observed periods. A cell phone camera (Oppo Ax7) was used to capture both movies and photos. Foraging ant species recorded in photos or movies were estimated to belong to the species as ants observed in nearby nests.