Phylogeography of Simulium siamense Takaoka and Suzuki complex (Diptera: Simuliidae) in Thailand

Abstract

The phylogeography of Simulium siamense complex was inferred from mitochondrial DNA sequences. A 586-bp fragment of the cytochrome oxidase I was sequenced for 92 individuals from 13 populations throughout Thailand, representing five cytoforms (A, B, C, F and G). The cytoforms are not genetically different at the molecular level except for cytoform B, which is genetically distinct from the others. This might indicate that cytoform B is a distinct species. Further morphological and molecular work using other genes is needed to clarify this. Our results also argue for the need of integrated approach, both cytological and molecular studies to understanding biodiversity of black flies. The star-like shape of the mtDNA genealogy is consistent with the sudden population expansion of the mismatch distribution analysis and large negative values of Fu's Fs and Tajima's D-tests, indicating a population demographic expansion. The expansion time is estimated to be in the late Pleistocene (about 120 000 years ago). Therefore, the overall low level of genetic structure could be due to sharing a recent history. The ancestral haplotype was found in the mountainous area in northeastern Thailand, suggesting that this area could have been the refugium of the species complex during the Pleistocene glaciations. Our results are consistent with previous findings about population expansion in response to the Pleistocene climatic change, thus revealing the importance of this historical event in shaping the genetic structure and diversity of Southeast Asian mainland species.

Mitochondrial DNA Markers Reveal High Genetic Diversity but Low Genetic Differentiation in the Black Fly Simulium tani Takaoka & Davies along an Elevational Gradient in Malaysia

“…The wide-scale study by Pramual et al [12] also revealed high genetic diversity of S. tani in Thailand, with 121 unique haplotypes from 147 individuals and haplotype diversity and nucleotide diversity of 0.8570–1.0000 and 0.0030–0.0155, respectively. Based on haplotype frequencies, the genetic diversity of S. tani in the present study was greater than that previously described in Thailand for S. tani (by 1.21 fold), S. feuerborni Edwards (2.03 fold), and S. siamense Takaoka & Suzuki (3.54 fold) [12], [28], [29]. The population expansion of S. tani occurring in the mid Pleistocene agreed with the previous findings in Thailand [12].…”

Population genetics and demographic history of guava fruit fly Bactrocera correcta (Diptera: Tephritidae) in northeastern Thailand

“…The beginning of this expansion was estimated to be at the end of the Pleistocene glaciations (approximately 15,000 years ago). The results are consist ent with previous studies on another fruit fly species, B. latifrons (Meeyen et al, 2014), and other insects such as mosquitoes (O'Loughlin et al, 2008;Morgan et al, 2011) and black flies (Pramual et al, 2005(Pramual et al, , 2011. Climatic con ditions during the Pleistocene glaciations in tropical Asia, including Thailand, were thought to be drier with lower temperatures (Penny, 2001).…”

“…Pleistocene glaciations) on current biodi versity. Previous studies on insects, such as mosquitoes (O'Loughlin et al, 2008;Morgan et al, 2011), black flies (Pramual et al, 2005(Pramual et al, , 2011 and another species of fruit fly, Bactrocera latifrons (Hendel) (Meeyen et al, 2014), indicate the important role of historical climatic changes in determining the genetic structure and diversity of South east Asian faunas.…”

DNA barcoding of tropical black flies (Diptera: Simuliidae) of Thailand

“…; Tangkawanit et al . ; Pramual & Wongpakam , ; Pramual & Kuvangkadilok ), population genetics and phylogeography (Pramual et al . , ; Pramual & Kuvangkadilok ; Pramual & Wongpakam ), and ecology (Pramual & Kuvangkadilok ; Pramual & Wongpakam ).…”