Phylogeography of the termite Macrotermes gilvus and insight into ancient dispersal corridors in Pleistocene Southeast Asia

Abstract

Dispersal of soil-dwelling organisms via the repeatedly exposed Sunda shelf through much of the Pleistocene in Southeast Asia has not been studied extensively, especially for invertebrates. Here we investigated the phylogeography of an endemic termite species, Macrotermes gilvus (Hagen), to elucidate the spatiotemporal dynamics of dispersal routes of terrestrial fauna in Pleistocene Southeast Asia. We sampled 213 termite colonies from 66 localities throughout the region. Independently inherited microsatellites and mtDNA markers were used to infer the phylogeographic framework of M. gilvus. Discrete phylogeographic analysis and molecular dating based on fossil calibration were used to infer the dynamics of M. gilvus dispersal in time and space across Southeast Asia. We found that the termite dispersal events were consistently dated within the Pleistocene time frame. The dispersal pattern was multidirectional, radiating eastwards and southwards out of Indochina, which was identified as the origin for dispersal events. We found no direct dispersal events between Sumatra and Borneo despite the presence of a terrestrial connection between them during the Pleistocene. Instead, central Java served as an important link allowing termite colonies to be established in Borneo and Sumatra. Our findings support the hypothesis of a north-south dispersal corridor in Southeast Asia and suggest the presence of alternative dispersal routes across Sundaland during the Pleistocene. For the first time, we also propose that a west-east dispersal through over-water rafting likely occurred across the Pleistocene South China Sea. We found at least two independent entry routes for terrestrial species to infiltrate Sumatra and Borneo at different times.

A new rhinoceros clade from the Pleistocene of Asia sheds light on mammal dispersals to the Philippines

“…Among the four hypothetical gateways to the Philippines (Dickerson, 1928;Brown et al, 2003), the northern route from Taiwan to Luzon seems for the moment to have only been active for shrews (Esselstyn & Oliveros, 2010). Interestingly, phylogeography of termites evidences a successful West-East rafting dispersion over the South China Sea from Thailand and through Vietnam to the Philippines between 1.09 and 0.42 Ma (Singham et al, 2017). These studies are generally underestimating the potential contribution of Pleistocene (and pre-Pleistocene) dispersals to the modern biodiversity of Island Southeast Asia.…”

Integrative Phylogeography Reveals Conservation Priorities for the Giant Anteater Myrmecophaga tridactyla in Brazil

“…A second hypothesis would be an increase in food availability (i.e., ants and termites) in some periods in the Pleistocene. Indeed, genetic studies of termite species in North America [105] and Southeast Asia [106] and of ant species in Europe [107] and Mexico [108] have all shown signs of contraction (glacial periods) and subsequent population expansion (interglacial) during the Pleistocene. The latter species is a neotropical ant that also inhabits the Brazilian CE and shows a sign of large population expansion in the last 30 ka [108].…”

Infestation Pattern and Population Dynamics of the Tropical Bed Bug, Cimex hemipterus (F.) (Hemiptera: Cimicidae) Based on Novel Microsatellites and mtDNA Markers

“…A total of 90 bed bugs were subjected to mtDNA analysis targeting the COI and 16S rRNA regions. PCR was conducted using a newly designed internal forward primer CH-COI-F (5′-GGCAGGGATGCTGGGAAC-3′) and the reverse primer LepR (5′-TAWACTTCWGGRTGTCCRAARAATCA-3′) [ 45 ] for COI gene, while the primer pair LR-J-13007 (‘5-TTACGCTGTTATCCCTAA-3′) [ 46 ] and LR-N-13398 (5′CGCCTGTTTATCAAAAACAT-3′) [ 47 ] were used for the 16S rRNA gene using PCR conditions as described in Veera Singham et al [ 48 ]. The PCR amplification was performed in 25 μL reaction containing 1X KAPA HiFi Hotstart Readymix (12.5 µL) (Kapa Biosystems, Wilmington, Massachusetts), each forward and reverse primers at a concentration of 0.2 µM (0.5 µL), ≈20 ng of DNA template (1.0 µL) and sterile distilled water up to 25 µL.…”