Genome-wide exploration reveals distinctive northern and southern variants of Clonorchis sinensis in the Far East.

Clonorchis sinensis is a carcinogenic liver fluke that causes clonorchiasis-a neglected tropical disease (NTD) affecting ~35 million people worldwide. No vaccine is available, and chemotherapy relies on one anthelmintic, praziquantel. This parasite has a complex life history and is known to infect a range of species of intermediate (freshwater snails and fish) and definitive (piscivorous) hosts. Despite this biological complexity and the impact of this biocarcinogenic pathogen, there has been no previous study of molecular variation in this parasite on a genome-wide scale. Here, we conducted the first extensive nuclear genomic exploration of C. sinensis individuals (n = 152) representing five distinct populations from mainland China, and one from Far East Russia, and revealed marked genetic variation within this species between "northern" and "southern" geographical regions. The discovery of this variation indicates the existence of biologically distinct variants within C. sinensis, which may have distinct epidemiology, pathogenicity and/or chemotherapic responsiveness. The detection of high heterozygosity within C. sinensis specimens suggests that this parasite has developed mechanisms to readily adapt to changing environments and/or host species during its life history/evolution. From an applied perspective, the identification of invariable genes could assist in finding new intervention targets in this parasite, given the major clinical relevance of clonorchiasis. From a technical perspective, the genomic-informatic workflow established herein will be readily applicable to a wide range of other parasites that cause NTDs.

--Review of the genus Diplazon/ Nees, 1819 (Hymenoptera: Ichneumonidae: Diplazontinae) from Japan.

Japanese species of the genus Diplazon Nees, 1819 are reviewed. Nine species are identified from Japan and one of them, D. pallicoxa Manukyan, 1987 is newly recorded. The distribution records of D. orientalis (Cameron, 1905) and D. tibiatorius (Thunberg 1822) are removed from the Japanese fauna. A key to Japanese species of this genus is provided.

Taxonomic notes on Exetastes fukuchiyamanus Uchida, 1928 (Hymenoptera, Ichneumonidae, Banchinae), with description of a new species from Japan and China.

Exetastes fukuchiyamanus Uchida, 1928 (Ichneumonidae, Banchinae) is redescribed and its taxonomic status and distribution in Japan and China is reviewed. A new species, E. compressus sp. nov., is described based on specimens collected from China and Japan.

Revision of the genus Amphirhachis Townes, 1970 (Hymenoptera, Ichneumonidae, Banchinae) from Japan.

The Japanese species of the genus Amphirhachis Townes, 1970 are revised. Four species are found from Japan and two them, A. fujieisp. n. and A. miyabisp. n. are here described as new. A key to world species of this genus is provided.

Genetic structure and demographic history of Lymantria dispar (Linnaeus, 1758) (Lepidoptera: Erebidae) in its area of origin and adjacent areas.

We analyzed the population genetic structure and demographic history of 20 Lymantria dispar populations from Far East Asia using microsatellite loci and mitochondrial genes. In the microsatellite analysis, the genetic distances based on pairwise FST values ranged from 0.0087 to 0.1171. A NeighborNet network based on pairwise FST genetic distances showed that the 20 regional populations were divided into five groups. Bayesian clustering analysis (K = 3) demonstrated the same groupings. The populations in the Korean Peninsula and adjacent regions, in particular, showed a mixed genetic pattern. In the mitochondrial genetic analysis based on 98 haplotypes, the median-joining network exhibited a star shape that was focused on three high-frequency haplotypes (Haplotype 1: central Korea and adjacent regions, Group 1; Haplotype 37: southern Korea, Group 2; and Haplotype 90: Hokkaido area, Group 3) connected by low-frequency haplotypes. The mismatch distribution dividing the three groups was unimodal. In the neutral test, Tajima's D and Fu's FS tests were negative. We can thus infer that the Far East Asian populations of L. dispar underwent a sudden population expansion. Based on the age expansion parameter, the expansion time was inferred to be approximately 53,652 years before present (ybp) for Group 1, approximately 65,043 ybp for Group 2, and approximately 76,086 ybp for Group 3. We propose that the mixed genetic pattern of the inland populations of Far East Asia is due to these expansions and that the inland populations of the region should be treated as valid subspecies that are distinguishable from other subspecies by genetic traits.