Interim profile, incomplete information
General Impact
In the same coastal areas in South Georgia where Trechisibus antarcticus has colonised, lives an endemic detritivorous beetle known as Hydromedion sparsutum (Perimylopidae). It is common especially in and beneath the tussock grass. The first three larval instars (stages) of H. sparsutum are easily taken prey by the carabid T. antarcticus. On sites colonised by the carabid, total abundances of larval and adult H. sparsutum are far lower (Ernsting et al. 1999).
Location Specific Impacts:Sth. Georgia Is. (sub-Antarctic) (Sth. Georgia and Sth. Sandwich Iss (sub-Antarctic)) 
Reduction in native biodiversity: In the same coastal areas where T. antarcticus has colonised lives an endemic detritivorous beetle known as Hydromedion sparsutum (Perimylopidae). It is common especially in and beneath the tussock grass. The first three larval instars (stages) of H. sparsutum are easily taken prey by the carabid T. antarcticus. In sites colonised by the carabid, total abundances of larval and adult H. sparsutum are far lower (Ernsting et al. 1999). Preys on the smaller larvae of H. sparsutum has caused decline in abundance and increase in body size of this native beetle (Convey et al. 2006b).
Biotic resistance of the native insect community against the invasion of the carabid is probably weak because of an abundance of prey (such as mites, springtails and small H. sparsutum larvae), and limited inter-specific competition for these resources (Ernsting et al. 1999).
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