Key to species of Ooceraea

There are two recent keys to workers of Ooceraea, the first by Zhou, Chen & Chen (2020) and a second by Bharti, Rilta & Dhadwal (2021).

Zhou, Chen & Chen (2020)
This key as been updated to include the species recently described by Bharti et al. (2021).

1

 * Antenna 8-segmented (China: Guangxi) Ooceraea octoantenna
 * Antenna 9-segmented
 * Antenna 10-segmented
 * Antenna 11-segmented

3

 * Propodeum armed with two pairs of denticles (Vietnam)  Ooceraea quadridentata
 * Propodeum armed without denticles

4

 * Anterior of  pronotum  with  distinct  ridge;  pronotum  in lateral  view  slightly  convex  dorsally;  postpetiole  in  dorsal view slightly broader than long (Sri Lanka)  Ooceraea coeca
 * Anterior of  pronotum  without  ridge;  pronotum  in  lateral view  distinctly  convex  dorsally;  postpetiole  in  dorsal  view slightly longer than broad (Sri Lanka)  Ooceraea fragosa

5

 * Compound eye present, comprising more than 10 ommatidia (India) Ooceraea besucheti
 * Compound eye absent or extremely vestigial

6

 * Postpetiole in dorsal view slightly longer than broad
 * Postpetiole in dorsal view slightly broader than long

7

 * Head coarsely  and  irregularly  rugose  and  punctuate (Solomon Islands)  Ooceraea pawa
 * Head only bearing regular punctures (New Guinea) Ooceraea pusilla

8

 * Dorsum of mesosoma smooth and shiny (australis) Ooceraea australis
 * Dorsum of mesosoma with abundant punctures

9

 * Diameter of punctures on dorsum of head as equal to or larger than the average distance separating them
 * Diameter of punctures on dorsum of head distinctly smaller than the average distance separating them

10

 * Posterior margin of head distinctly concave in the middle (India) Ooceraea alii
 * Posterior margin of head almost straight, at most shallowly concave

11

 * Antennal scrobe surface smooth and shiny (Fiji) Ooceraea fuscior
 * Antennal scrobe surface with annular fine striation (New Guinea) Ooceraea papuana

12

 * For full-face view  the  head  is  broader  posteriorly  (The tropical regions)  Ooceraea biroi
 * For full-face view the head is as broad in front as behind (Fiji) Ooceraea crypta

13

 * Head as long as broad; eyes present; propodeal lobes reduced; petiolar node in lateral view hemiglobular; anteroventral part of subpetiolar process sickleshaped; head and body comparatively more pilose (India) (Fig. A, B) Ooceraea joshii
 * Head distinctly longer than broad; eyes absent; propodeal lobes roundly produced; petiole node in lateral view rectangular; anteroventral part of subpetiolar process forming a rectangular and semitransparent lobe (India) (Fig. C, D) Ooceraea decamera

Bharti, Rilta & Dhadwal (2021)
Note: Comprehensive morphological diagnosis and image of Ooceraea guizhouensis is not available, so this species has been not included in the key. However, as cited in the comparative diagnosis, Ooceraea guizhouensis is close to Ooceraea besucheti and Ooceraea fragosa, but differs in having coarse pilose punctures on the surface of the mandibles, petiolar node distinctly longer than broad and is without eyes.

1

 * Whole body variously sculptured
 * Whole body not sculptured, mesosoma smooth and shiny (Fig. A) Ooceraea australis

2

 * Body predominantly punctate (Fig. A)
 * Body predominantly foveate (Fig. B)

3

 * Anterolateral shoulders of the first gastric segment as seen from above broadly rounded and gradually widening caudad (Fig. A) Ooceraea biroi
 * Anterolateral shoulders of the first gastric segment abruptly rounded, accentuating the medium concavity that receives the postpetiole (Fig. B)

4

 * Postpetiole distinctly longer than broad (Fig. A)
 * Postpetiole broader than long (New Guinea) (Fig. B) Ooceraea papuana

5

 * Head coarsely and irregularly rugose and punctuate (Solomon Islands) Ooceraea pawa
 * Head regularly punctate (New Guinea) (Fig. A) Ooceraea pusilla

6

 * Lateral ridge of posterior face of propodeum armed with two pairs of denticles (Vietnam) (Fig. A) Ooceraea quadridentata
 * Lateral ridge of posterior face of propodeum without denticles (Fig. B)

7

 * Spaces between foveolae shagreen-like, giving the integument a rough appearance (Fig. A)
 * Spaces between foveolae smooth, giving the integument a shiny appearance (Fig. B)

8

 * Species large in size (HW> 70mm); posterior margin of head almost straight (Fig. A)
 * Species small in size (HW< 40 mm); posterior margin of head distinctly concave in the middle (Fig. B) Ooceraea alii

9

 * Sides of propodeum and sides of petiole with dense, deeply impressed foveae that are discernibly wider in diameter than propodeal spiracle or foveae on head. Dark species (Fiji) (Fig. A) Ooceraea fuscior
 * Sides of propodeum and sides of petiole with sparse, lightly impressed foveae that are not discernibly wider in diameter than propodeal spiracle or foveae on head. Pale species (Fiji) (Fig. B) Ooceraea crypta

10

 * Antenna 8-segmented (China) Ooceraea octoantenna
 * Antenna more than 8-segmented

11

 * Antenna 10-segmented
 * Antenna 11-segmented

12

 * Head as long as broad; eyes present; propodeal lobes reduced; petiolar node in lateral view hemiglobular; anteroventral part of subpetiolar process sickleshaped; head and body comparatively more pilose (India) (Fig. A, B) Ooceraea joshii
 * Head distinctly longer than broad; eyes absent; propodeal lobes roundly produced; petiole node in lateral view rectangular; anteroventral part of subpetiolar process forming a rectangular and semitransparent lobe (India) (Fig. C, D) Ooceraea decamera

13

 * Body shallowly and coarsely foveolate; eye present with multiple ommatidia (India) (Fig. A) Ooceraea besucheti
 * Body conspicuously foveolate; eye absent or vestigial (Fig. B)

14

 * Anterior portion of pronotum with distinct ridge; petiole and postpetiole in dorsal view broader than long (Sri Lanka) (Fig. A) Ooceraea coeca
 * Anterior portion of pronotum without distinct ridge; petiole and postpetiole in dorsal view longer than broad (Sri Lanka) (Fig. B) Ooceraea fragosa