Genus
Microthylax
6 species
*Microthylax* Rivalier, 1954 is a small Neotropical genus of tiger beetles found along the coastal margins of the Caribbean basin and adjacent northern South America. These metallic, depressed beetles are specialists of intertidal and supratidal sand flats and mudflats — among the most demanding habitats occupied by any cicindelid. Active at night, *Microthylax* navigates the rhythms of the tide rather than the sun. The genus currently comprises approximately two species following recent taxonomic revisions.
Diagnosis
DIAGNOSIS — *Microthylax* Rivalier, 1954. Body 9–13 mm, depressed; shape flattened, L:W ratio 2–3. Coloration metallic. Labrum subquadrate. Eyes medium, not strongly enlarged. Wings fully developed. Nocturnal; restricted to intertidal and supratidal sand or mudflat substrates. Neotropical distribution (Caribbean basin and adjacent northern South America). Approximately 2 species following transfer of *M. schwarzi* to *Eunota*. No confusion genera recorded for this genus.
Etymology
From Greek *mikrós* (small) + *thúlax* (pouch, sac) — referring to small specific structures.
Species (6)
Distribution map — GBIF occurrences
GBIF · © OpenStreetMap · © CartoDB
Overview
*Microthylax* Rivalier, 1954 is a small Neotropical genus of tiger beetles found along the coastal margins of the Caribbean basin and adjacent northern South America. These metallic, depressed beetles are specialists of intertidal and supratidal sand flats and mudflats — among the most demanding habitats occupied by any cicindelid. Active at night, *Microthylax* navigates the rhythms of the tide rather than the sun. The genus currently comprises approximately two species following recent taxonomic revisions.
Type species: Cicindela olivacea Chaudoir, 1854 [by original designation (Rivalier 1954)]
1. Wiesner, J. (2020) — checklist authority 2. Rivalier, E. (1954) — original genus description 3. Pearson, D.L. & Vogler, A.P. (2001) — Caribbean Cicindelidae ecology 4. Duran, D.P. & Gough, H.M. (2020) — Validation of tiger beetles as distinct family (Cicindelidae) and reclassification within Coleoptera. Systematic Entomology 45(4): 723-729. DOI: 10.1111/syen.12440 [validates Cicindelidae as separate family] 5. Gough, H.M., Duran, D.P., Kawahara, A.Y. & Toussaint, E.F.A. (2018) — A comprehensive molecular phylogeny of tiger beetles (Coleoptera, Carabidae, Cicindelinae). Systematic Entomology 43(3): 567-586. DOI: 10.1111/syen.12324 [ML phylogeny of 328 taxa, 9 gene regions] 6. Wiesner, J. (2020) — Checklist of the Tiger Beetles of the World, 2nd edition (Verzeichnis der Sandlaufkäfer der Welt, 27. Beitrag zur Kenntnis der Cicindelidae). Winterwork, Borsdorf, 534 pp. [Authoritative current world checklist] 7. Rivalier, É. (1954) — Démembrement du genre Cicindela Linné. II. Faune américaine. Revue Française d'Entomologie 21(4): 249-268. [Part II — American fauna; genera Brasiella, Microthylax, Pachydela, Tribonia and others established] 8. Horn, W. (1908, 1910, 1915) — Coleoptera Adephaga, fam. Carabidae, subfam. Cicindelinae. In: Wytsman, P. (Ed.) Genera Insectorum, fascicles 82a, 82b, 82c. L. Desmet-Verteneuil, Bruxelles. BHL bibliography/45481 [foundational historical monograph of Cicindelidae, treating all genera known at the time] 9. Knisley/Kippenhan/ Brzoska (2014) — Terrestrials Arthropod Reviews 7(2014) (p.93-145) ; Conservation statuts of US T.B. ; Knisley/Kippe +4 citations · full list in paid edition
Living Book · World Monograph 2026
Genera and Subgenera of Tiger Beetles
240 genera · 3,715 taxa · 194-character matrix · 12 months free updates