Carebara bokorensis

Carebara bokorensis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Crematogastrini
Genus:	Carebara
Species group:	pygmaea
Species:	C. bokorensis
Binomial name
	Carebara bokorensis; Matsuura & Hosoishi, 2024

Carebara bokorensis, from Cambodia (Bokor National Park, Kampot), was collected from decayed wood (Matsuura & Hosoishi, 2024). In Thailand, it nests in rotting wood in lowland dry evergreen forests (200–500 m a.s.l.) (Wimolsuthiku et al., 2024).

At a Glance

• Ergatoid queen

Photo Gallery

Matsuura et al. (2024), Fig. 1. Carebara bokorensis, holotype major worker (KUECCRB001). A – body in profile; B – dorsal view of body; C – head in full-face view.
Matsuura et al. (2024), Fig. 2. Carebara bokorensis, paratype minor worker (KUECCRB004). A – body in profile; B – dorsal view of body; C – head in full-face view.
Matsuura et al. (2024), Fig. 3. Carebara bokorensis nesting in decayed wood (S. Hosoishi).

Identification

Major workers can be distinguished from the other species in the genus by the following characters:

11-segmented antennae
punctation on posterior surface of head
long petiolar pedicel
well-developed scutellum
metanotal groove separated by elevated band

Minor workers:

11-segmented antennae
median concavity of anterior clypeal margin
entirely rounded promesonotum
short petiolar pedicel
presence of subpetiolar process in the subcaste

Carebara bokorensis shares most features except for promesonotal suture with the C. pygmaea species group. Jaitrong et al. (2021) defines promesonotal suture of major workers as indistinct in definition of C. pygmaea species group, and this is thought to be due to the exceptionally partial presence of promesonotal suture in Carebara panhai. Carebara bokorensis has a distinct promesonotal suture in major workers, but other morphological characters are consistent with the definition of the species group. Therefore, it is appropriate to include this species in the species group. Furthermore, the major workers of this species also have scutellum, which is not found in the species group. Developed scutellum in major workers are found in some species such as Carebara oni, Carebara phragmotica and Carebara aberrans. Although it is beyond this study to infer it, such character state can be found in different lineages of Carebara.

The Carebara pygmaea species group includes five species, C. bokorensis, Carebara pygmaea, Carebara rubra, Carebara transversalis and Carebara panhai. The major workers of C. bokorensis are distinguished from the other four species in the species group by the presence of punctation on posterior surface of head, presence of scutellum and projection in the metanotal groove. The minor workers of C. bokorensis are distinguished from the three species, C. pygmaea, C. rubra and C. panhai (minor worker of C. transversalis is unknown), in the species group by the presence of a well-developed subtriangular subpetiolar process and medial concavity of anterior clypeal margin.

Wimolsuthiku et al. (2024):

Major (Fig. 3): head, promesonotum, and gastral tergite I with dense and long erect hairs mixed with decumbent hairs; with head in full-face view, posterior one-third with dense fovea, lacking transverse striation, while anterior two-thirds with longitudinal striation; eye small, with ca. 13–15 ommatidia; gastral tergite I punctate. Minor (Fig. 5): propodeal dorsum entirely punctate; petiole and postpetiole with decumbent hairs; propodeal junction roundly convex; body reddish brown.

The major worker of this species can be easily distinguished from other species of the group in having dense erect and decumbent hairs on the head, promesonotum and gaster; posterior one third of head with dense punctures (with transverse striation in other species); and dense punctures on gastral tergite I (more or less smooth and shiny in other species). This species is similar to Carebara parva and Carebara panhai. See C. parva and C. panhai for comparison.

Carebara bokorensis is also similar to Carebara altinodus. However, C. bokorensis can be easily separated from C. altinoda by:

in major worker, Dorsa of head, mesosoma, and gaster with dense erect hairs mixed with dense decumbent hairs (with dense decumbent on head and with sparse erect hairs on mesosoma and gaster in C. altinoda)
in major worker, without a pair of minute horns on vertex (with a pair of minute horns in C. altinoda)
in minor worker, propodeum in profile roundly convex (bluntly angulates in C. altinoda)
in minor worker, distance between propodeal spiracle and metanotal groove ca. 4 times as long as distance between propodeal spiracle and propodeal junction (ca. 8.5 times in C. altinoda).

Keys including this Species

Key to Carebara pygmaea species group of Thailand

Distribution

Wimolsuthiku et al. (2024), FIGURE 13. Distribution of Carebara pygmaea species group in Thailand.

Latitudinal Distribution Pattern

Latitudinal Range: 13.5° to 10.6°.


North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

Source: Matsuura et al., 2024; Wimolsuthiku et al., 2024

Distribution based on type material

Cambodia (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Castes

Ergatoid queen

See Fig. 4. Similar to the major worker in structure, sculpture, coloration and pilosity, with the following conditions that should be noted: body slightly larger in average (HW 0.89–0.92 in ergatoid queen; 0.84–0.96 mm in major worker); ocelli present (absent in major worker), located on vertex; distance between anterior ocellus and lateral ocelli slightly shorter than distance between lateral ocelli; eye larger than in the major.

Wimolsuthiku et al. (2024), FIGURE 4. Carebara bokorensis, ergatoid queen (THNHM-I-00028220). A, Body in profile view; B, head in full-face view; 2C, body in dorsal view.
Wimolsuthiku et al. (2024), FIGURE 5. Carebara bokorensis, non-type minor worker (THNHM-I-00028204). A, Body in profile view; B, head in full-face view; 2C, body in dorsal view.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

bokorensis. Carebara bokorensis Matsuura & Hosoishi, in Matsuura, Hosoishi & Sokh, 2024: 3, figs. 1, 2 (s.w.) CAMBODIA.
- Type-material: holotype major worker, 2 paratype major workers, 7 paratype minor workers.
- Type-locality: holotype Cambodia: Kampot Prov., Bokor Nat. Park, 10°36’N, 104°06’E, 19.xii.2011, SH11-Cam-55 (S. Hosoishi); paratypes with same data.
- Type-depository: KUEC.
- Distribution: Cambodia.

Type Material

Holotype (major worker): Cambodia: Bokor National Park, 663m alt., Kampot Province, N 10°36 E 104°06, 19. XII 2011, S. Hosoishi leg. SH11-Cam-55, decayed wood (Institute of Tropical Agriculture, Kyushu University, Fukuoka, Japan (KUEC), collection code KUECCRB001).
Paratypes: same data as holotype, 2 major workers (KUEC, collection code KUECCRB002, KUECCRB003) and 7 minor workers (KUEC, collection code KUECCRB004, KUECCRB005, KUECCRB006, KUECCRB007, KUECCRB008, KUECCRB009, KUECCRB010).

Description

References