Key to Carebara of India

There are three keys to species of Carebara known from India, one based on major workers, one for minor workers and one for queens.

These keys are based on Bharti & Kumar (2013), Bharti et al. (2014), Akbar & Bharti (2017) and Dhadwal & Bharti (2022).

The following species do not have the descriptions of majors and are not included in the major worker key: Carebara bengalensis, Carebara carinata, Carebara lamellifrons, Carebara leei, Carebara lignata, Carebara propomegata, Carebara raja, Carebara rothneyi, Carebara similis and Carebara wroughtonii.

Five species are known only from queens or queens and males: Carebara bengalensis, Carebara lamellifrons, Carebara leei, Carebara raja and Carebara rothneyi.

The minor worker key is lacking Carebara periyarensis and Carebara similis.

None of these keys include all known species. This will improve with time, but is a limitation to these keys at the current time.

Major Workers

1

 * Antenna 11-segmented
 * Antenna 9-segmented

2

 * Head truncate, shield like, with frontal lobes extended forward forming broad rounded lamina; posterolateral edges sharply angulate (Oriental Region: India; Kerala; Iritty; Karnataka; Gundlupet. Akbar & Bharti, 2017, Figs. 1-2; Dhadwal & Bharti, 2022, Fig. 8A) Carebara nayana
 * Head not truncate, sides straight to weakly convex; posterolateral corners rounded (Dhadwal & Bharti, 2022, Fig. 8B)

3a

 * Propodeum with a pair of distinct long spines (Dhadwal & Bharti, 2022, Fig. 9A)
 * Propodeum with a pair of denticles (Dhadwal & Bharti, 2022, Fig. 9B) Carebara periyarensis

3b

 * Head with a deep median longitudinal groove and a single ocellus, body strongly sculptured, relatively larger in size and dark reddish brown to black in color, SI 41-42 (Wide spread: Afrotropical Region, Indo-Australian Region, Oriental Region, Palaearctic region. Akbar & Bharti, 2017, Figs. 3-4; Dhadwal & Bharti, 2022, Fig. 10A) Carebara diversa
 * Head without deep median longitudinal groove and without ocellus, body weakly sculptured, relatively smaller in size and reddish brown in color, SI 46-51 (Wide spread: Australasian region, Afrotropical, Indo-Australian Region, Oriental Region, Palaearctic region. Akbar & Bharti, 2017, Figs. 5-6; Dhadwal & Bharti, 2022, Fig. 10B) Carebara affinis

4

 * Eyes distinct with numerous ommatidia (>8); base of first gastral tergite finely reticulate with traces of fine longitudinal rugae (Oriental Region: India) Carebara aborensis
 * Eyes rudimentary with few ommatidia (<4); base of first gastral tergite smooth and shinning

5

 * Vertex without a pair of distinct horns or minute teeth
 * Vertex with a pair of distinct horns or minute teeth

6

 * Head distinctly longer than broad, smooth and shiny (Oriental Region: India; Jammu and Kashmir; Bilawar. Akbar & Bharti, 2017, Figs. 7-8) Carebara rectangulata
 * Head almost as broad as long with distinct striations sculpture throughout (Oriental Region: India, Sri Lanka. Akbar & Bharti, 2017, Figs. 9-10) Carebara nana

7

 * Vertexal corners protruding into a pair of well developed acute horns or spines
 * Vertex with a pair of minute horns or teeth in lateral view

8

 * Head rectangular with straight parallel sides, punctured only and finely longitudinally rugulose anteriorly; occiput and vertex smooth and shinning (Oriental Region: India (Andretta, Himachal Pradesh). Akbar & Bharti, 2017, Figs. 11-12) Carebara hornata
 * Head with convex sides, sparsely punctured and longitudinally obscurely striated anteriorly; occiput and vertex wrinkled (Oriental Region, Palaearctic region. Akbar & Bharti, 2017, Figs 13-14) Carebara asina

9

 * Propodeum unarmed, posterodorsal corner rounded or bluntly angled
 * Propodeum with a pair of protruding dents or spines

10

 * Cephalic dorsum unsculptured, smooth and shining; vertexal horns reduced (Oriental Region: India; Himachal Pradesh; Mandi, Andretta, Jammu and Kashmir; Kathua; Punjab; Maharaja Ranjeet Sagar Dam; Uttarakhand; Forest Research Institute, Akbar & Bharti, 2017, Figs. 15-16) Carebara dentata
 * Cephalic dorsum sculptured, dull; vertexal horns more prominent

11

 * Cephalic dorsum with a single median ocellus. Lateral sides of head straight (Oriental Region: India; Kerala; Salim Ali Bird Sanctuary. Akbar & Bharti, 2017, Figs 17-19) Carebara quratulain
 * Cephalic dorsum without a single median ocellus. Lateral sides of head convex

12

 * Posterodorsal corner of propodeum smoothly rounded; dorsum of head weakly sculptured (Akbar & Bharti, 2017, Figs. 20-21) Carebara rectidorsa
 * Posterodorsal corner of propodeum clearly bluntly angled; dorsum of head strongly sculptured (Oriental Region: India; Arunachal Pradesh, Lumla, Kerala, Periyar tiger reserve, Thanikkudy. Akbar & Bharti, 2017, Figs. 22-23) Carebara terayamai

13

 * Head with lateral sides convex, almost as long as broad (CI 84-85) (Oriental Region: India; Uttarakhand; Dakpathar, Rajaji forest; Himachal Pradesh; Ghati, Lwasa; Jammu and Kashmir; Shukrala. Akbar & Bharti, 2017, Figs. 24-25) Carebara spinata
 * Head with parallel lateral sides, longer than broad (CI 74-78)

14

 * Anterior margin of clypeus concave without lateral developed teeth; Propodeal spines well developed; masticatory margin of mandible with 5-teeth (Oriental Region: India; Arunachal Pradesh; Lumla; Sikkim; Rorathang; Kerala; Periyar tiger reserve, Thanikkudy, Akbar & Bharti, 2017, Figs. 26-27) [[Carebara obtusidenta]
 * Anterior margin of clypeus with two prominent lateral teeth; Propodeal spines reduced; masticatory margin of mandible with 4-teeth (Oriental Region: India; Kerala; Silent Valley National park. Akbar & Bharti, 2017, Figs. 28-29) Carebara mukkaliensis

Minor Workers

1

 * Antenna 11- segmented . . . . . Carebara carinata
 * Antenna 9-10 segmented . . . . . 2

2
return to couplet #1
 * Eyes absent . . . . . 3
 * Eyes present . . . . . 4

3
return to couplet #2
 * TL 2.5 mm; articulation of the femora and tibiae of the legs with a brown ring . . . . . Carebara lignata
 * TL 1mm; articulation of the femora and tibiae of the legs without brown ring . . . . . Carebara asina

4
return to couplet #2
 * Eyes with 2 ommatidia, clypeus without lateral carinae . . . . . Carebara aborensis
 * Eyes absent or with single ommatidium; clypeus with lateral carinae . . . . . 5

5
return to couplet #4
 * Propodeal spines present . . . . . Carebara spinata
 * Propodeum rounded or obtusely angled, not dentate . . . . . 6

6
return to couplet #5
 * Head reticulate or densely fovulate punctured; propodeal lobes large and broad with rounded posterior margin; mandibles with 4 teeth . . . . . Carebara propomegata
 * Head smooth or rugulose; propodeal lobes small, narrow or absent; mandibles with 5 acute teeth . . . . . 7

7
return to couplet #6
 * Head opaque with front and sides of striate, antenna 10 segmented . . . . . Carebara wroughtonii
 * Head smooth and shiny, antenna 9 segmented . . . . . 8

8
return to couplet #7
 * Eyes situated at a distance of 0.08 mm from mandibular insertions into head; EI 6.25-7.41, SI 75-77.78 . . . . . Carebara dentata
 * Eyes situated at more than distance of 0.08 mm from mandible insertion into head; EI ≤ 4, SI ≤ 72 . . . . . 9

9
return to couplet #8
 * Eyes elongate, not rounded, sides of head comparatively weakly convex; EI 3.12, SI 71.88 . . . . . Carebara hornata
 * Eyes rounded, sides of head comparatively strongly convex; EI 3.13-3.33, SI 68.75-70 . . . . . Carebara rectangulata

Queens

1

 * Antenna 10-11 segmented . . . . . 2
 * Antenna 9 segmented . . . . . 3

2
return to couplet #1
 * Antenna 10 segmented, more than 10 mm . . . . . Carebara lignata
 * Antenna 11 segmented, less than 4.5-4.6 mm . . . . . Carebara lamellifrons

3
return to couplet #1-q
 * Length > 5mm, colour more or less brown . . . . . 4
 * Length < 5mm, colour more or less yellow . . . . . 6

4
return to couplet #3-q
 * Clypeus feebly but distinctly bicarinate . . . . . Carebara bengalensis
 * Clypeus not carinate . . . . . 5

5
return to couplet #4-q
 * Anterior border of clypeus emarginated in the middle; body 5-5.5 mm longer . . . . . Carebara raja
 * Anterior border of clypeus not emarginated, body 7-8 mm longer . . . . . Carebara leei

6
return to couplet #3-q
 * Postpetiole transverse, much broader than long . . . . . Carebara asina
 * Postpetiole not broader than long . . . . . Carebara rothneyi