TY - JOUR
T1 - Extremely divergent host plant acceptance with gene flow between sympatric host races of the phytophagous ladybird beetle Henosepilachna diekei
AU - Matsubayashi, Kei W.
AU - Kahono, Sih
AU - Hartini, Sri
AU - Katakura, Haruo
N1 - Funding Information:
We thank the head of the Research Center for Biology and the head of the Zoological Division, Research Centre for Biology, Indonesian Institute of Science ? LIPI, for permitting our experiments in Indonesia. We thank S. Nakano and N. Fujiyama for valuable information on the beetles, W. A. Noerdjito, and R. Ubaidillah for field and laboratory support, M. T. Kimura, N. Kobayashi, T. Katoh, I. Ohshima, T. Kohyama, Y. Ohta and S. Kikuta for helpful comments on analysis and the manuscript and Sarino, Gianto, and Uchen for assistance in field observations and laboratory experiments in Indonesia. All experiments were undertaken at the Zoology Division, Research Centre for Biology, Indonesian Institute of Science ? LIPI. This study was supported by Grants-in-Aid from the Japan Society for the Promotion of Science to H. Katakura (Nos. 14204081 and 18207005) and to K. W. Matsubayashi (No. 16H06178), and by a post-doctoral fellowship from the Japan Society for the Promotion of Science for Young Scientists (No. 10J03106) to K. W. Matsubayashi.
Publisher Copyright:
© 2019 The Entomological Society of Japan
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Ecological divergence alone can prevent the majority of gene flow in the absence of other forms of reproductive isolation. Although the importance of ecological divergence in promoting reproductive isolation has been broadly recognized, its net impact on speciation has rarely been estimated in the wild. The phytophagous ladybird beetle Henosepilachna diekei Jadwiszczak & Wegrzynowicz includes two sympatric host races that are reproductively isolated solely by extreme specialization to either of the host plants Mikania micrantha Kunth (Asteraceae) or Leucas lavandulifolia Sm. (Lamiaceae) in West Java, Indonesia. To investigate the impact of differential host use as an isolating barrier, we carried out adult host acceptance tests and molecular population genetic analyses based on mitochondrial ND2 and nucleic ITS2 gene sequences using 13 wild populations of the host races, including four sympatric population pairs. Almost all individuals of these host races persistently accepted only the original host plant. We detected restricted but a degree of gene flow between these host races. A migration event occurred only in very recent time compared to their divergence time, indicating recent secondary contact of these host races in the surveyed area. These results reveal the remarkably large impact of host-plant shift over almost the entire process of speciation and illustrate that ecological divergence has been maintained even under the presence of a certain degree of gene flow.
AB - Ecological divergence alone can prevent the majority of gene flow in the absence of other forms of reproductive isolation. Although the importance of ecological divergence in promoting reproductive isolation has been broadly recognized, its net impact on speciation has rarely been estimated in the wild. The phytophagous ladybird beetle Henosepilachna diekei Jadwiszczak & Wegrzynowicz includes two sympatric host races that are reproductively isolated solely by extreme specialization to either of the host plants Mikania micrantha Kunth (Asteraceae) or Leucas lavandulifolia Sm. (Lamiaceae) in West Java, Indonesia. To investigate the impact of differential host use as an isolating barrier, we carried out adult host acceptance tests and molecular population genetic analyses based on mitochondrial ND2 and nucleic ITS2 gene sequences using 13 wild populations of the host races, including four sympatric population pairs. Almost all individuals of these host races persistently accepted only the original host plant. We detected restricted but a degree of gene flow between these host races. A migration event occurred only in very recent time compared to their divergence time, indicating recent secondary contact of these host races in the surveyed area. These results reveal the remarkably large impact of host-plant shift over almost the entire process of speciation and illustrate that ecological divergence has been maintained even under the presence of a certain degree of gene flow.
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U2 - 10.1111/ens.12382
DO - 10.1111/ens.12382
M3 - Article
AN - SCOPUS:85074102200
VL - 22
SP - 404
EP - 412
JO - Entomological Science
JF - Entomological Science
SN - 1343-8786
IS - 4
ER -