title: Co-occurrence of ecologically equivalent cryptic species of spider wasps.
abstract: Many cryptic species have been discovered in various taxonomic groups based on molecular phylogenetic analyses and mating experiments. Some sympatric cryptic species share equivalent resources, which contradicts the competitive exclusion principle. Two major theories have been proposed to explain the apparent lack of competitive exclusion, i.e. niche-based coexistence and neutral model, but a conclusive explanation is lacking. Here, we report the co-occurrence of cryptic spider wasp species appearing to be ecologically equivalent. Molecular phylogenetic analyses and mating experiments revealed that three phylogenetically closely related species are found sympatrically in Japan. These species share the same resources for larval food, and two of the species have the same niche for nesting sites, indicating a lack of competitive exclusion. This evidence may suggest that ecologically equivalent species can co-occur stably if their shared resources are sufficiently abundant that they cannot be over-exploited.
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Engineering , Tokyo Metropolitan University , Hachioji, Tokyo 192-0397 , Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kurushima
authors.affiliation: Graduate School of Science and Technology, and Department of Mathematical and Systems Engineering, Shizuoka University, Hamamatsu 432-8561, Japan; Department of Environmental and Forest Biology, State University of New York College of Environmental Science and Forestry, Syracuse, New York 13210, USA; Marine Biosystems Research Center, Chiba University, Kamogawa, Chiba 299-5502, Japan.
authors.forename: Jin
authors.identifier: 0000-0003-1610-1386
authors.initials: J
authors.lastname: Yoshimura
authors.affiliation: Bureau of Ecological Research , National Institute of Ecology , Seocheon, Chungcheongnam, 33657 , Republic of Korea.
authors.forename: Jeong-Kyu
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Department of Forest Environment Protection, College of Forest and Environmental Sciences , Kangwon National University , Chuncheon, Kangwon 24341 , Republic of Korea.
authors.forename: Jong-Kuk
authors.initials: JK
authors.lastname: Kim
authors.affiliation: 10-1 Oharano-Taniue, Takarazuka, Hyogo 669-1211 , Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nishimoto
authors.affiliation: Hokkaido Research Center , Forestry and Forest Products Research Institute , Sapporo, Hokkaido 062-8516 , Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Sayama
authors.affiliation: 2-2-B205 Hirafuku, Tsuyama, Okayama 708-0872 , Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kato
authors.affiliation: Science and Technology Division, Okinawa College, National Institute of Technology, Nago, Okinawa 905-2192, Japan; Department of Botany, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA.
authors.forename: Kenta
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Laboratory of Animal Ecology, Department of Ecology and Systematics, Graduate School of Agriculture , Hokkaido University , Sapporo 060-8589 , Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Hasegawa
authors.affiliation: Department of Biology , University of California , Riverside, CA 92521 , USA.
authors.forename: Derek A
authors.initials: DA
authors.lastname: Roff
authors.affiliation: Department of Biological Sciences, Graduate School of Science and Engineering , Tokyo Metropolitan University , Hachioji, Tokyo 192-0397 , Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Shimizu
keywords: coexistence; competitive exclusion principle; cryptic species; reproductive isolation; sympatric species