Beetles of North Carolina
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Scientific Name: Common Name:
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View Carabidae Members:
Members of Trechus:
3 NC Records

Trechus balsamensis Barr, 1962 - No Common Name

Taxonomy
Family: Carabidae Subfamily: Trechinae                                                             
Comments: One of 82 species in this genus that have been recorded in North America north of Mexico, 42 of which occur in North Carolina (Bosquet, 2012). Trechus balsamensis belongs to subgenus Microtrechus and was included in the Nebulosus Species Group by Barr (1979). In addition to balsamensis, Bosquet (2012) includes 21 species in this group, 18 of which occur in North Carolina and the rest in Tennessee.
Species Status: The type locality is Waterrock Knob in the Plott Balsam Mountains (Barr, 1962)
Identification
Field Guide Descriptions: Online Resources: BugGuide, Wikipedia, GBIF   iNaturalistTechnical Description, Adults/Nymphs: Barr (1962)                                                              
Comments: "Closely similar to nebulosus" (Barr, 1962). Members of this genus generally show too little variation in pattern for standard photographs to be used to identify particular species.
Structural Features: As a member of subgenus Microtrechus, only the first segment of front tarsus is enlarged in males. This species is distinguished from other members of its species group morphometrically and by features of the aedeagus (Barr, 1962, 1979).
Distribution in North Carolina
County Map: Clicking on a county returns the records for the species in that county.
Flight Dates:
 High Mountains (HM) ≥
 4,000 ft.
 Low Mountains (LM) <
 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)
Click on graph to enlarge
Habitats and Life History
Habitats: Waterrock Knob is 6,293', with the summit supporting a stand of Spruce-fir Forest. Spruce-fir forest also exists on Mt. Kephardt, where T. balsamensis was found by Caterino in 2021. Litter and soils inhabited by this species must be kept cool and moist, helped by the dense canopy provided by spruce and fir.
See also Habitat Account for Spruce-Fir Forests
Diet: Predatory on small insects and other invertebrates
Observation Methods:
Abundance/Frequency:
Adult Phenology:
Status in North Carolina
Natural Heritage Program Status: [SR]
Natural Heritage Program Ranks: GH [G1] [S1]
State Protection:
Comments: NatureServe (accessed 2021-01-20) considers this species to be possibly extinct However, it was recorded in 2004 by Donabauer (2005b) and in 2018 and 2021 by M.S. Caterino (GBIF). As a species known from just two high elevation peaks, it is likely highly vulnerable to the warming and drying impacts of climate change. It is also vulnerable to the various impacts to the canopy of Spruce-fir Forests, which it depends on for maintaining its cool, moist, forest-floor microclimate. The habitat at this site is only partially protected, with some areas altered by development. We are unaware of any management plans that have been developed specifically for this species and we rate its probability of becoming extirpated from North Carolina over the next twenty years as 0.8.