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| Representatives of the Asian and the American Rhaphidophoridae. b Aemodogryllinae, Tachycines (Tachycines) coreana (Yamasaki) stat. resurr. (Jindo, Korea). d Aemodogryllinae, Paratachycines (Paratachycines) ussuriensis Storozhenko (Gwangju, Korea). f Anoplophilinae, Anoplophilus koreanus Storozhenko & Paik (Mt. Jirisan, Korea). g Rhaphidophorinae, Rhaphidophora taiwana Shiraki, 1930 (Ishigaki, Japan). h Ceuthophilinae, Ceuthophilus sp. (California, U.S.). i Gammarotettiginae, Gammarotettix genitalis Caudell (California, U.S.). Photographs by Do-Yoon Kim. |
Abstract
Cave crickets (Rhaphidophoridae) are insects of an ancient and wingless lineage within Orthoptera that are distributed worldwide except in Antarctica, and each subfamily has a high level of endemicity. Here, we show the comprehensive phylogeny of cave crickets using multi-gene datasets from mitochondrial and nuclear loci, including all extant subfamilies for the first time. We reveal phylogenetic relationships between subfamilies, including the sister relationship between Anoplophilinae and Gammarotettiginae, based on which we suggest new synapomorphies. Through biogeographic analyses based on divergence time estimations and ancestral range reconstruction, we propose novel hypotheses regarding the biogeographic history of cave crickets. We suggest that Gammarotettiginae in California originated from the Asian lineage when Asia and the Americas were connected by the Bering land bridge, and the opening of the western interior seaway affected the division of Ceuthophilinae from Tropidischiinae in North America. We estimate that Rhaphidophoridae originated at 138 Mya throughout Pangea. We further hypothesize that the loss of wings in Rhaphidophoridae could be the result of their adaptation to low temperatures in the Mesozoic era.
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| Representatives of the Asian and the American Rhaphidophoridae. a Aemodogryllinae, Tachycines (Tachycines) asynamorus Adelung (Taean, Korea). b Aemodogryllinae, Tachycines (Tachycines) coreana (Yamasaki) stat. resurr. (Jindo, Korea). c Aemodogryllinae, Diestrammena (Diestrammena) unicolor Brunner-Wattenwyl (Ulsan, Korea). d Aemodogryllinae, Paratachycines (Paratachycines) ussuriensis Storozhenko (Gwangju, Korea). e Aemodogryllinae, Paratachycines (Hemitachycines) boldyrevi (Uvarov) (Mt. Jirisan, Korea). f Anoplophilinae, Anoplophilus koreanus Storozhenko & Paik (Mt. Jirisan, Korea). g Rhaphidophorinae, Rhaphidophora taiwana Shiraki, 1930 (Ishigaki, Japan). h Ceuthophilinae, Ceuthophilus sp. (California, U.S.). i Gammarotettiginae, Gammarotettix genitalis Caudell (California, U.S.). Photographs by Do-Yoon Kim. |
Conclusion:
Our phylogenic analysis, which included all known subfamilies, revealed a unique and novel placement of the Asian subfamily Anoplophilinae. We also confirmed that the endemic distribution of Rhaphidophoridae as a result of winglessness is valid. Beringia, which connected Asia and North America, and the opening of the western interior seaway during the Cretaceous period coincide with the estimated divergence time of the Rhaphidophoridae lineages. The difference between the geological events and the molecular clock can be explained by several hypotheses regarding the dispersal capabilities of Rhaphidophoridae, but it can also be caused by a limitation of the dataset. Here, we suggest a hypothesis that global temperature and climate changes have affected lineage diversification and propose a narrative hypothesis that adaptation to low temperatures caused the loss of wings, leading to the endemic distribution of Rhaphidophoridae. Further research is needed to fully test these interesting hypotheses and gain a deeper understanding of the evolution and diversification of the cave cricket.
Do-Yoon Kim, Sangil Kim, Hojun Song and Seunggwan Shin. 2024. Phylogeny and Biogeography of the Wingless orthopteran Family Rhaphidophoridae. Communications Biology. 7: 401