Male Oodes helopioides, copyright U. Schmidt.

Belongs within: Harpalinae.
Contains: Panagaeitae, Chlaenius.

The Oodini are a group of ground beetles characterised by a twisted fold near the apex of the elytral epipleura (Bell 1990).

The Oodini: some like it wet
Published 16 June 2023

Among the widespread tribes of the carabid beetles are the Oodini, representatives of which can be found on all continents except Antarctica. Oodins are distinguished from other carabids by elytra with the eighth stria (counted from the suture line outwards; the eighth stria runs close to the outer margin of the elytron) much more deeply impressed by the rest. The seventh stria comes to an end before the end of the elytron so the seventh and eighth intervals on either side of it are fused distally where they are often raised into a ridge. The ninth interval, outside the eighth stria, forms a gutter along the elytral margin. Most of the integument is devoid of setae and punctures though a pair of supraorbital setae are present on the head (Guéorguiev 2014). The body is commonly ovate, with the pronotum about as wide as the elytra at the base and narrowing anteriorly.

Stenocrepis cuprea, copyright Robert Webster.

Guéorguiev (2014) described two genera from southeastern Asia, Bamaroodes and Thaioodes, that are somewhat anomalous in having a narrower pronotum. They also share a number of unusual features, such as having the tarsal claws on each leg nearly parallel instead of the widely diverging claws of other genera. Bamaroodes also has the external gutter fading towards the rear half of the elytra. Nevertheless, the deeply impressed eighth stria together with features of the male genitalia confirm their position as oodins.

Thaioodes piceus, from Guéorguiev (2014). Scale bar = 2 mm.

Many oodins are semi-aquatic, living among vegetation in or near standing water. Others live among forest leaf litter. Reduced flight abilities are known among some forest-dwelling species but all semi-aquatic species retain fully developed wings (Bousquet 1996). Ponds can dry up, and it’s important to be able to get to a new one.

Systematics of Oodini

Characters (from Bell 1990): Mandibles usually pointed, not strongly curved; scrobal seta absent. Eye usually large; one orbital seta over each eye. Pronotum more or less flattened, broadest at or near base, basal impressions scarcely evident. Elytra glabrous; stria 8 much deeper than stria 7; interval 9 narrow, careniform; epipleura interrupted by twisted fold near apex. Metepimeron visible as scale-like structure overlapping abdominal sternum I at side.

<==Oodini [Oodinae]B90
    |--+--+--Adelopomorpha glabraOM08
    |  |  `--PanagaeitaeOM08
    |  `--+--Dercylus [Dercylini]OM08
    |     `--Anatrichis LeConte 1853OM08, LM87
    |          |--*A. minuta (Dejean 1831) [=Oodes minutus]LM87
    |          |--A. australasiae Chaudoir 1882 [incl. Oodes pygmaeus Macleay 1888]LM87
    |          |--A. lilliputana (Macleay 1888) [=Oodes lilliputanus]LM87
    |          |--A. oblonga Horn 1891BB01
    |          |--A. pusilla Sloane 1910LM87
    |          `--A. sexstriata Sloane 1910LM87
    `--+--Stenocrepis Chaudoir 1857OM08, BB01
       |    |--S. (Stenocrepis) insulana (Jacquelin du Val 1857)BB01
       |    `--S. (Stenous Chaudoir 1857)BB01
       |         `--S. (S.) elegans (LeConte 1851)BB01
       `--+--Oodes Bonelli 1810OM08, LM87
          |    |--*O. helopioides (Fabricius 1792) [=Carabus helopioides]LM87
          |    |--O. abaxoides Lucas 1846E12
          |    |--O. amaroidesOM08
          |    |--O. americanusBB01
          |    |--O. bostockii Castelnau 1867LM87
          |    |--O. denisonensis Castelnau 1867LM87
          |    |--O. fitzroyensis Macleay 1888LM87
          |    |--O. froggatti Macleay 1888LM87
          |    |--O. impressus Chaudoir 1882LM87
          |    |--O. inornatus Castelnau 1867 [incl. O. proximus Castelnau 1867]LM87
          |    |--O. latior Csiki 1931 [=O. latus Castelnau 1867 non LaFerté 1851]LM87
          |    |--O. mauritanicus Lucas 1846E12
          |    |--O. modestus Castelnau 1867LM87
          |    |--O. oblongus Castelnau 1867 [incl. Coptocarpus planipennis Macleay 1878, C. riverinae Macleay 1873]LM87
          |    |--O. paroensis Castelnau 1867LM87
          |    |--O. parviceps Sloane 1896LM87
          |    |--O. siamensis Chaud. 1882B89
          |    |--O. trisulcatus Castelnau 1867LM87
          |    `--O. waterhousei Castelnau 1867 [incl. O. interioris Castelnau 1867]LM87
          `--Chlaeniini [Callistini, Chlaeniides, Chlaeniinae]OM08
               |--Rhysotrachelus quadrimaculatusB55
               |--Ocybatus deyrolleiB55
               |--Stenodinodes neposB55
               |--Pachydinodes conformisB55
               |--Chlaenites capicolaB55
               |--Pseudochlaeniellus paenulatusB55
               |    |--C. hessei Basilewsky 1949B55
               |    `--C. pulchellusB55
               |--Leptochlaenius variansB55
               |    |--L. v. variansB55
               |    |--L. v. angolanus Basilewsky 1955B55
               |    `--L. v. verecundusB55
               |    |--T. gonioderusB55
               |    |    |--T. g. gonioderusB55
               |    |    `--T. g. nigrofemoralisB55
               |    `--T. obesus [incl. T. ovalipennis]B55
               |    |--H. goossensi [incl. H. goossensi var. nigrocyanescens]B55
               |    `--H. lineatusB55
               |         |--H. l. lineatusB55
               |         `--H. l. tristisB55
               |    |--C. denticulatusB55
               |    |    |--C. d. denticulatusB55
               |    |    `--C. d. elatusB55
               |    |--C. euryscopusB55
               |    `--C. sulcipennisB55
               |         |--C. s. sulcipennisB55
               |         `--C. s. sulcatulusB55
               `--Callistomimus suturalis Fleutiaux 1887B89
Oodini incertae sedis:
  Evolenes LeConte 1853BB01
    `--E. exarata (Dejean 1831)BB01
  Dercylinus Chaudoir 1883BB01
    `--D. impressus (LeConte 1853)BB01
  Systolocranius validusB55
  Paroodes similatusB55
    |--L. deceptorB55
    `--L. politusB55
  Nanodiodes Bousquet 1996 [incl. Nanodes Habu 1956 nec Schoenherr 1825 nec Stephens in Shaw 1826]BB01
  Oodinus Motschulsky 1864BB01
    |--O. alutaceus (Bates 1882)BB01
    `--O. pseudopiceus Bousquet 1996BB01
  Lachnocrepis LeConte 1853BB01
    `--L. parallela (Say 1830)BB01
  Simous aeneus (Laferté 1851) [=Oodes aeneus]B89

*Type species of generic name indicated


[BB01] Ball, G. E., & Y. Bousquet. 2001. Carabidae Latreille, 1810. In: Arnett, R. H., Jr & M. C. Thomas (eds) American Beetles vol. 1. Archostemata, Myxophaga, Adephaga, Polyphaga: Staphyliniformia pp. 32–132. CRC Press: Boca Raton.

[B55] Basilewsky, P. 1955. Carabidae (Coleoptera) de l’Angola (première partie). Diamang Publicações Culturais 27: 91–137.

[B89] Bates, H.-W. 1889. Contributions a la faune Indo-Chinoise. 3e mémoire. Carabidae. Annales de la Société Entomologique de France, 6e série 9: 261–286.

[B90] Bell, R. T. 1990. Insecta: Coleoptera Carabidae adults and larvae. In: Dindal, D. L. (ed.) Soil Biology Guide pp. 1053–1092. John Wiley & Sones: New York.

Bousquet, Y. 1996. Taxonomic revision of Nearctic, Mexican, and West Indian Oodini (Coleoptera: Carabidae). Canadian Entomologist 128: 443–537.

[E12] Evenhuis, N. L. 2012. Publication and dating of the Exploration Scientifique de l’Algérie: Histoire Naturelle des Animaux Articulés (1846–1849) by Pierre Hippolyte Lucas. Zootaxa 3448: 1–61.

Guéorguiev, B. 2014. Two new related oodine genera in the Oriental region, with remarks on the systematic position of the genera Hololeius and Holosoma (Coleoptera, Carabidae). Deutsche Entomologische Zeitschrift 61 (2): 87–104.

[LM87] Lawrence, J. F., B. P. Moore, J. E. Pyke & T. A. Weir. 1987. Zoological Catalogue of Australia vol. 4. Coleoptera: Archostemata, Myxophaga and Adephaga. Australian Government Publishing Service: Canberra.

[OM08] Ober, K. A., & D. R. Maddison. 2008. Phylogenetic relationships of tribes within Harpalinae (Coleoptera: Carabidae) as inferred from 28S ribosomal DNA and the wingless gene. Journal of Insect Science 8: 63.

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