Camponotus adustus Viehmeyer, 2021

Ward, Philip S. & Boudinot, Brendon E., 2021, Grappling with homoplasy: taxonomic refinements and reassignments in the ant genera Camponotus and Colobopsis (Hymenoptera: Formicidae), Arthropod Systematics & Phylogeny 79, pp. 37-56 : 37

3.2.3. Camponotus adustus Viehmeyer stat. n. Fig. 8A, B

Camponotus (Myrmamblys) bellus subsp. adustus Viehmeyer, 1916: 159. Holotype worker (by monotypy), Singapore (H. Overbeck) (ZMHB) [examined via image on AntWeb: FOCOL2281].

Ca. adustus was described by Viehmeyer (1916) as a subspecies of Ca. bellus Forel, but examination of the original descriptions, images of types, and more recent material indicates that these two are distinct species. Camponotus bellus (syntype major worker, Amboina, Indonesia ( Biró) [MHNG]; examined via image on AntWeb: CASENT0910513) has a matte integument and more abundant standing pilosity on the mesosoma, including the pronotum (Fig. 8C, D ). In contrast, the body of Ca. adustus is predominantly shiny and standing pilosity is sparse on the mesosoma, being restricted to a single pair of long setae on the mesonotum and one pair at the junction of the dorsal and declivitous faces of the propodeum (Fig. 8A, B ). Moreover, the two taxa have been recorded co-occurring in Singapore and remaining distinct ( Viehmeyer 1916).

In addition to the foregoing pilosity characteristics, the minor worker of Ca. adustus has striking anterior and posterior protuberances on the dorsal face of the propodeum, and both the dorsal and declivitous faces are notably concave in lateral view (Fig. 8B ). Under this general morphotype, however, there is a bewildering diversity of color forms whose taxonomic status is unclear. One of these, Ca. leucodiscus Wheeler, has also been treated as a subspecies of Ca. bellus , and is here raised to species (below), but its relationship to Ca. adustus remains to be clarified. The New Guinea species Camponotus weismanni Forel (syntype worker, Bismarck Archipelago; examined via image on AntWeb: FOCOL2297) might be a senior synonym of Ca. adustus , but the worker propodeum has less well-developed protuberances and a correspondingly less concave dorsal surface in profile.

Figures

Figure 8. Camponotus workers, full-face (dorsal) views of head (A, C) and lateral views of body (D, E); scale bars 0.5 mm. A, B: Camponotus adustus, holotype worker (FOCOL 2281); scale bars = 0.5 mm. C, D: Camponotus bellus, syntype major worker (CASENT 0910513). Images from AntWeb (www. antweb. org); photographers Christiana Klingenberg (A, B), and Zach (Ziv) Lieberman (C, D).