Termitodius woodruffi Skelley, Clavijo-Bustos, and Keller, 2022

Skelley, Paul E., Clavijo-Bustos, Julian & Keller, Oliver, 2022, Extinct or extant? A new species of Termitodius Wasmann, 1894, (Coleoptera: Scarabaeidae: Aphodiinae: Rhyparini) with a short review of the genus, Insecta Mundi 2022 (915), pp. 1-14 : 6-10

Termitodius woodruffi Skelley, Clavijo-Bustos, and Keller , new species

Figures 7–17 , 220–22, 24–32

Diagnosis. A species of Termitodius with the pronotal paramedian costa having the anterior lobe elongate in dorsal view and evenly rounded in lateral view, posterior part of discolateral pronotal costa absent medially, elytra intercostal areas glossy and entirely lacking transverse wrinkles, caudal bulbs of elytra appearing bilobed in dorsal view, posterior lobe of pronotal lateral margin concave to sharp posterior angle, and in distribution ( Colombia).

Description. Holotype male. Body. Length 3.44 mm, width 1.44 mm; color reddish brown; dorsum strongly costate often encrusted debris [removed for study], costae with fine punctures bearing fine setae; surface between costae glossy ( Fig. 7–13 ). Head. Clypeus with anteriorly sinuate on each side, appearing multi-dentate; short sharp denticle on each side of anterior margin, lobes on gena angulate. Clypeus with central disc distinctly convex; with two weakly-raised parallel costae evident by punctation; peridiscal impression fine. Frons with four short but distinct longitudinal costae (two frontodiscal and two frontolateral), each with fine punctures; punctures of frons with setae similar to those on clypeus ( Fig. 15 ). Pronotum. Surface glossy and apparently impunctate between costae; anterior portions of costae enlarged, appearing swollen and lobe-like. Paramedian costa complete, reduced behind anterior lobe, anterior lobe elongate, outwardly convex in dorsal view, evenly rounded on top in lateral view. Discolateral costa interrupted by pronotal depression, anterior lobe rounded, costa behind depression reduced to small tubercle at posterior margin base and near anterior fovea, absent medially. Submarginal costa complete, partially interrupted behind anterior lobe and at basal third. Lateral margin with laterally flattened anterior lobe on anterior third; posterior lobe prominent, concave laterally to sharp posterior angle. Scutellar shield not visible. Elytron. Surface glossy and apparently impunctate between costae. Juxtasutural costa complete, fine, not prominently raised. Discomedial costa complete, prominent, swelling posteriorly to a weakly triangularly shaped postdiscal bulb. Discolateral costa complete, prominent, equally developed entire length to caudal trichome. Posthumeral costa sinuate basally, showing humeral umbone anteriorly, posteriorly becoming smaller, reaching caudal trichome. Marginal costa smaller than others, complete from anterior margin to caudal bulb. Caudal bulb in caudal view nearly spherical ( Fig. 14 ), with impunctate depression on dorsal surface, creating the internal and external protrusion visible in dorsal and lateral views, appearing bilobed. Metaventrite. Surface evenly, distinctly punctate. Median impression distinct on posterior half, anterolateral and postlateral juxtacoxal impressions weak. Abdomen. Ventrites finely punctate; groove along anteror margin of ventrites weakly fluted. Terminal ventrite with weak depressions along anterior margin. Pygidium. Surface with median longitudinal carina, longitudinal furrow on each side; punctation similar to punctation of abdominal ventrites. Legs. All femora and tibiae with surface evenly distinctly punctate. Profemur enlarged; mesofemur moderately swollen medially; metafemur narrow entire length, reaching elytral apex. Protibia with two small apical teeth, exterior margin weakly curved. Mesotibia with subapical concavity on inner margin ( Termitodius -type in Skelley 2007); subapical tooth sharp. Metatibia narrow entire length, almost cylindrical in cross section. Tarsi shorter than tibia, tarsomeres thickened, basal meso- and metatarsomere as long as next two tarsomeres; claws reduced. Male genitalia. Not studied on unique holotype; paratype with genitalia accessible ( Fig. 20–21 ) have phallobase elongate, tubular; parameres short about a third length of phallobase; paramere apex ventrally curved in lateral view, broadly rounded in caudal view.

Variation. Variation is seen in the distinctness of the lobes on the elytral caudal bulb ( Fig. 7, 9 ). In all, the surface is at least slightly concave, flattened, compared with the convex to distinctly rounded bulb of the other species. Other variations in surface structure (e.g. weak elytral interval sculpture Fig. 7 vs. no sculpture Fig. 9 ) could relate to resin preservation and subsequent viewing methods. Visibility of resin-preserved specimens is usually poor, hindering detailed studies of variation.

Materials examined. Male holotype ( Fig. 9–15 ) label data ( Fig. 16 ): “// Feby 1924 / WMMann // Santa Anna / Colombia // Collection / WMMann // Termitodius / cornonatus Wasm. / ReyesCastillo. det. 86 // Coptotermes / sp. D. R. Smith 67 // [yellow paper with red ink, OLCartwright’s handwriting] N. Sp. N3[?] median / pronotal

carinae / [blue ink] #1 // [red paper] HOLOTYPE ♂ / Termitodius / woodruffi Skelley , / Clavijo, & Keller //”, deposited in the USNM.

Paratypes (>200). Colombian specimens reported in the 17 copal pieces reported here are considered paratypes, and will have paratype labels associated with each piece of copal in their repositories. COLOMBIA: Boyacá Department: One medium piece with ~ 10 paratypes ( AAIC) ; One medium piece with 2 paratypes ( AAIC) ; One small piece with 2 paratypes ( AAIC). Santander Department: Four pieces with 1 paratype each ( CEMT, Fig. 30 ) ; One piece with 3 paratypes ( CEMT, Fig. 29 ) ; One small piece with 1 paratype ( IFIC) ; One small piece with 2 paratypes ( AAIC). Questionable locality data: One small piece with 5 paratypes labeled “copal from Kacheta, Colombia”, with “Kacheta” crossed out and replaced with “Cachira ??” ( CMNC, Fig. 27 ). No locality data: One medium-sized piece with about 15 paratypes including the male specimen (arrow) with genitalia visible and removed for study ( RLBC donated to FSCA, Fig. 32 ) ; One large piece with ~ 100 paratypes ( FSCA, Fig. 26 ) ; One medium piece with ~ 40 paratypes ( IAvH-E, Fig. 31 ) ; One medium piece with 17 paratypes ( RLBC) ; One small piece with 1 paratype ( OKIC) ; One small piece with 3 paratypes and millipedes ( REWC, Fig. 28 , current repository unknown) .

Distribution. ‘Santa Anna’ refers to a municipality in the department of Magdalena, Colombia. Records at a department level certainly correspond to localities in the Magdalena valley. In this way, the species is distributed in the Magdalena province, in the Pacific dominion of the Brazilian subregion ( Fig. 33 ).

Etymology. Noun in the genitive case. Named for Robert E. “Bob” Woodruff, a coleopterist and dealer in amber fossils. Bob worked hard identifying insects in amber for other dealers with the underlying goal of getting the best insect fossils to the appropriate scientists for taxonomic research. He built an amber collection at the FSCA and was very fond of amber from the Dominican Republic. It is fitting we name a resin preserved species for him. Termitodius is one of the rarest genera in collections of extant species and belongs in Bob’s favorite beetle family, the scarabs. A few years ago, Bob gave PES a few pieces as gifts to work jointly on this description. Bob died before the manuscript could be completed.

Comments. Detailed study of the recent specimen and those visible in copal yielded no characters sufficient to consider the two as distinct species. This would indicate the copal containing this species is from a younger deposit. Despite the lack of consensus about the age of Colombian copal, radiocarbon dating has been used, placing pieces from Santander in the order of 60 to around 10,000 years old ( Clifford et al. 1997; Penney et al. 2013b; Modi et al. 2021).

Small copal pieces often lack host termites. Larger pieces have termite hosts and often other arthropod inclusions (e.g., millipedes, Fig. 28 ) that may also be termite nest guests. Some pieces have too many beetles to easily count ( Fig. 26 ). With the knowledge that the copal is of a more recent origin, a soldier of the termite preserved with copal preserved T. woodruffi ( Fig. 22–23 ) was shown to R. Scheffrahn (University of Florida, Ft. Lauderdale) who identified it as a Coptotermes Wasmann ( Isoptera : Rhinotermitidae ). He stated (Scheffrahn in lit. 2005; Scheffrahn et al. 2015) that there is only one New World endemic species presently in Colombia, C. testaceus (L.). These are known to live in the heartwood of living trees ( Garcia Costa et al. 2020), which might explain why T. woodruffi has been preserved so abundantly in amber.

Compared to other aphodiines, T. woodruffi is the most common resin preserved aphodiine. The copal piece in Figure 26 likely has more specimens of T. woodruffi , than there are specimens of all species in collections. Bob Woodruff once owned a piece about the size of a grapefruit that had multiple hundreds of specimens. He sold that piece which he stated (pers. comm. PES) was on display in a museum. Specimens of this species are present in several collections and numerous private holdings not mentioned here. Photographs of T. woodruffi have appeared in various publications, like Penny and Green (2011), and on websites discussing copal or selling pieces.

Despite that most of the Termitodius species are known from a couple of localities and few specimens, the abundance of T. woodruff in copal is likely atypical. In contrast, only one living specimen of the species has been recorded and collected almost a century ago. These aspects may suggest a couple probable explanations that are not exclusive between each other. First, the rarity nowadays of the species is because of its association with termites in heartwood of living trees and ineffective collecting techniques, as true for other members of the genus and the tribe, or even for the subfamily ( Smith and Skelley 2007).

Second, the rarity of T. woodruffi could also be explained by the probable reduction of its populations given the age of copal pieces and the climate and landscape changes that have taken place in Colombian tropical dry forests in recent years. Tropical dry forests are suffering from climate changes, especially more in the Americas than in other regions of the world ( Miles et al. 2006). Also, the distribution of dry forests in Colombia have been affected by landscape changes caused primarily by urbanization, agriculture, and deforestation ( Etter et al. 2006; Fernández-Méndez et al. 2014). As a result, the dry forests of Colombia in the Magdalena valley and Caribbean region where T. woodruffi has been recorded, have been declining in recent years and are vulnerable ecosystems that are endangered and in critical risk ( Fernández-Méndez et al. 2014; Etter et al. 2015).

In conclusion, we feel the rarity of Termitodius in collections is only partially due to changes in the landscape which restrict populations to suitable habitats. But, the most important factor to their rarity is in the difficulty of sampling from live termite nests. As long as the host termites survive, populations of T. woodruffi will survive. If we had a better understanding how the copal was formed, we might gain some insight into these beetles. Obviously, we need to sample more appropriately for these taxa to find them.

Figures

Figure 26. Large copal piece with about 100 T. woodruffi paratypes (FSCA).

Figure 33. Distribution of Termitodius species.

Figures 1–10. Termitodius species dorsal habitus and lateral pronotum. 1–2) T. coronatus, cotype. 3–4) T. araujoi. 5–6) T. chaki, paratype. 7–8) T. woodruffi, copal paratype. 9–10) T. woodruffi, holotype.

Figures 11–16. Termitodius woodruffi, recent specimen, holotype. 11) Dorsal habitus. 12) Ventral habitus. 13) Lateral habitus. 14) Elytra apex, caudal view. 15) Head, anterior view. 16) Labels.

Figures 17–25. Images of Termitodius and host. 17) T. woodruffi, paratype, cut open in copal processing, note genitalia inside body (arrow). After photographing, genitalia removed for study.18–19) T. araujoi male genitalia, caudal and lateral view. 20–21) T. woodruffi male genitalia of paratype in Fig. 17, caudal and lateral view. 22) T. woodruffi with worker host termite.23) Soldier termite with T. woodruffi. 24–25) T. woodruffi, individual paratypes.

Figures 27–32. Some smaller copal pieces containing T. woodruffi paratypes, host termites and other inclusions. 27) CMNC. 28) REWC. 29–30) CEMT. Scale line = 1 mm. 31) IAvH-E. 32) FSCA (ex. RLBC), arrow indicates male with genitalia extracted, see Fig. 17. Photos for Figures 29–30 by Vinícius Costa-Silva (CEMT).