Agonum at stream edge - Agonum errans Sevenmile Creek, 8 km NW of Helena, Lewis and Clark County, Montana, USA September 14, 2021 Size: 8.5 mm
Shiny black beetle with coppery iridescence, crawling actively across cobbles at stream edge. Collected. Ruderal floodplain community with Kochia scoparia, Chenopodium simplex, Chenopodium berlandieri, Helianthus annuus, and Cleome serrulata. Midday to early afternoon, sunny, 66 F to 73 F, gentle to fresh W breeze, good air quality.
Elevation ca 4000 feet. Disturbed riparian corridor on stream restoration site within a patchwork of native and non-native grassland.
Keyed to genus in Lindroth 1961. Characters include 3 punctures on the 3rd elytral interval; 2 lateral punctures on the pronotum; mentum with median tooth; 2 punctures above each eye; epipleura not crossed; and tibiae slender, only slightly widened apically. Tentatively keyed to A. muelleri. 3 small punctures on the 3rd elytral interval, plus a possible 4th beyond the apex of the scutellar stria. Well-formed lateral pronotal bead connected to well-formed basal bead. Iridescence of elytra uniform. Several short setae present on the underside of the apical metatarsomere. Basal antennomere and legs rather pale, except tarsi dark. Epipleura dark, however, which does NOT match with the description of this species.
Images of this individual: tag all Contributed by Shane Sater on 9 December, 2021 - 10:09pm Last updated 11 January, 2022 - 12:51pm |