The genetic differentiation of a cricket (Velarifictorus micado) with
two modes of life cycle in East Asia after the middle Pleistocene
Abstract
Cricket Velarifictorus micado is widely distributed in East Asia and
colonized North America since 1959. It has been reported that they had
two modes of life cycle and distributed in southern and northern Asia
respectively. Aimed to investigate the biogeographic boundary between
the two groups and the causes of differentiation, mitochondrial
fragments including COI and CytB were used for phylogenetic analysis,
time estimation and demographic analysis. The results showed that, (i)
Haplotype network indicated that V. micado has diversified to three
lineages based on COI. Individuals with egg diapause lived in northern
Asia, whereas those with egg and nymph diapause lived in southern Asia,
and the populations colonized North America belongs to the egg diapause
group from both North and South Asia. (ii) The molecular chronograms
indicated that the first diversification between individuals in the
northern and southern Asia occurred during ~0.79 Ma BP
in the Middle Pleistocene Transition. The second event occurred in
southern individuals during ~0.49 Ma BP, when the
glaciers developed in Yulong mountain (Yunnan province). (iii) V. micado
has diversified to two main clades based on CytB. The individuals
distributed in southern China have not been differentiated. Haplotype
network indicated that the egg diapause lived in southern China most
possibly originated from Yunnan, where lies at the foot of the Tibetan
plateau. Our study suggested that the twice divergence of V. micado
co-occurred with tendency of cooling climatic in Asia after the
Mid-Pleistocene.