Taxonomic History (provided by Barry Bolton, 2020)
A cryptic inhabitant of forest floor leaf litter and rotten wood; from seasonal forests of Mexico and northern Central America.
Distribution: Geographic regions
(According to curated Geolocale/Taxon lists): Americas: Belize Biogeographic regions
(According to curated Bioregion/Taxon lists): Neotropical
Northern Mexico (Nuevo León) to Honduras.
In the southern portion of its range, Octostruma trithrix
occurs in a variety of forested habitats: wet to seasonal dry, second growth to mature. It is typically lowland, occurring from sea level to around 700 m. In the northern part of the range it occurs in cloud forest, up to 1200 m elevation. Almost all collections are from Berlese and Winkler samples of sifted litter and rotten wood from the forest floor. In quantitative 1 m2 litter plot samples, within-sample abundance is tens of workers or fewer, but the species can occur frequently, suggesting a high density of small colonies. Dealate queens may occur together with workers in litter samples.
Mandible with 8 teeth, tooth 1 a broad blunt lamella, strongly differentiated from tooth 2, teeth 2–5 acute, similar in shape, with denticles between them; teeth 5–8 forming an apical fork, with 5 and 8 large, 6 and 7 small partially confluent denticles (O. balzani
complex); face with erect setae present on posterolateral margins of head (absent in O. amrishi
and O. gymnogon
); in most workers of a series, a seta present between anterior seta on side of head near eye and medial vertex seta (this seta typically absent in O. balzani
, O. megabalzani
, O. amrishi
, and O. gymnogon
); mesosomal dorsum with one pair of erect setae (absent in O. amrishi
, O. gymnogon
; 2 pairs in O. lutzi
); metanotal groove not impressed in profile view (impressed in O. balzani
and O. megabalzani
See under O. balzani
Specimen Habitat Summary
Found most commonly in these habitats: 73 times found in tropical rainforest, 21 times found in 2º wet forest, 33 times found in lowland wet forest, 10 times found in 2º lowland tropical rainforest, 10 times found in mature wet forest, 9 times found in tropical moist forest, 2 times found in mixed secondary rainforest, 1 times found in wet forest, 2 times found in 2º lowland rainforest, 2 times found in mixed rainforest, ...
Found most commonly in these microhabitats: 168 times ex sifted leaf litter, 2 times ex sifted litter, 1 times sifted litter (leaf mold, rotten wood), 1 times ex forest litter, 1 times at bait.
Collected most commonly using these methods: 148 times MiniWinkler, 13 times maxiWinkler, 9 times Berlese, 2 times Winkler, 1 times baiting, 1 times Berlese/Winkler.
Elevations: collected from 25 - 1200 meters, 263 meters average
Collect Date Range: collected between 1945-08-14 and 2019-06-22
Type specimens: holotype Octostruma trithrix Longino 2013: casent0639179; paratype Octostruma trithrix Longino 2013: casent0639174, casent0639175, casent0639176, casent0639177, casent0639178, casent0639180, casent0639181, casent0639182, casent0639183, casent0639184
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