This paper describes a new species of a soldierless termite of the widespread Neotropical genus Aparatermes. Fontes (1986) described Aparatermes as a new genus, with Aparatermes abbreviatus (Silvestri 1901), formerly Anoplotermes, as the type species. Although Fontes (1986) recognized the importance of including digestive tube morphology in soldierless termite descriptions, as shown by Sands (1972) and Mathews (1977), he did not describe the enteric valve of A. abbreviatus. In addition, Fontes (1998) later transferred Anoplotermes cingulatus (Burmeister, 1839) to Aparatermes.

Aparatermes silvestrii (Emerson, 1925) was first included in Ruptitermes (Araujo 1977) and then synonymized the species with Aparatermes cingulatus by Šobotník et al. (2010). However, according to Acioli and Constantino (2015), A. silvestrii and A. cingulatus can be differentiated by their imagoes and disjunct geographic distribution. In their identification key, Bourguinon et al. (2016b) included the enteric cushions with scales and sometimes spines as a unique character to differentiate Aparatermes from Ruptitermes and other Apicotermitinae genera. We herein describe a new Aparatermes species, A. thornatus, based primarily on coloration, size, and digestive tube characters of the worker caste, in addition to mitochondrial gene cytochrome c oxidase subunit 1 (COI) sequences.

Materials and Methods

Specimens included in this paper were collected and preserved in 85% ethanol by O. Pinzón in Colombia, and R. Scheffrahn and his team in French Guiana, Ecuador, Trinidad and Tobago, and deposited at Colección Entomológica Forestal de la Universidad Distrital “Francisco Jose de Caldas” in Bogota, Colombia, and the University of Florida, Termite Collection at the Fort Lauderdale Research and Education Center, Fort Lauderdale, Florida, USA, respectively.

The enteric valve (EV) was dissected by excising the second proctodeal segment (P2) of the worker's gut with its content teased out using a pair of forceps. The tube was immersed in PVA mounting medium (Bioquip, Rancho Dominguez, California, USA), to completely detach the enteric valve from surrounding muscle tissue, then cut longitudinally to splay open the enteric valve for mounting in the medium. Description of the worker gut follows the terminology of Sands (1972) and Noirot (2001). Enteric valves of specimens from A. abbreviatus, A. cingulatus, and A. silvestrii from previous samples deposited at the University of Florida, Termite Collection were dissected and included for comparison. Morphometric characters (Table 1) were measured following those of Roonwal (1970). Measurements were obtained with a micrometric reticule on the eyepiece of an Olympus SZX9 (Center Valley, Pennsylvania, USA) stereomicroscope.

Table 1.

Measurements (mm) of 19 workers from 7 colonies of Aparatermes thornatus (Roonwal, 1961, equivalence in parenthesis).

Mitochondrial gene cytochrome c oxidase subunit 1 (COI) sequences from 2 samples of A. thornatus (UF EC 1334-1, BOLD accession number: ABV3376 and LS-2013 1573, BOLD: AAU1550) were obtained by DNA extraction, and PCR performed by the Canadian Centre for DNA Barcoding (University of Guelph, Guelph, Ontario, Canada) following standard high-throughput protocols (de Waard et al. 2008). The PCR employed the primers LepF1 and LepR1 (Hebert et al. 2003) that generated 652bp of the barcode region of COI. A phylogenetic tree was created under Bayesian Inference (BI) with the sequences of A. thornatus, 1 of Ruptitermes arboreus (BOLD: ACT1328), and 48 GenBank sequences: 35 sequences of Neotropical Apicotermitinae (21 species, 13 genera), 8 non-Neotropical Apicotermitinae genera, 5 non-Apicotermitinae Termitidae, and 1 Rhinotermitidae. The tree was constructed under the same parameters of other recently published papers on Neotropical Apicotermitinae (e.g., Carrijo et al. 2015; Scheffrahn et al. 2017). Sequences were aligned under MUSCLE algorithm implemented in Geneious v6.1.6 (Biomatters Ltd., Auckland, New Zealand). The Bayesian Inference analysis was conducted using Heterotermes crinitus (Emerson) (Blattodea: Rhinotermitidae) as an outgroup. The substitution model was the GTR + I + G, selected under the Akaike Information Criterion with the jModelTest2 (Darriba et al. 2012). The XML input files were generated with BEAUti 1.8.0 and the Bayesian Inference performed with BEAST 1.8.0 (Drummond et al. 2012). A Yule speciation process, with a random starting tree and strict molecular clock, was used as tree priors. Four Markov Chain Monte Carlo (MCMC) searches were conducted, each one for 20,000,000 generations, and were combined to search the most probable tree. Convergence and stationarity were assessed with Tracer 1.5 (Rambaut et al. 2014) and the first 1,000 trees were discarded as burn-in with TreeAnnotator 1.8.0 and visualized using FigTree 1.3.1.

Fig. 1.

Aparatermes thornatus worker: (A) dorsal view of head and fore legs (inset shows coloration and pigment variant); (B) lateral view of head and thorax; (C) lateral view of habitus; (D) ventral view of fore coxae; (E) mandibles.

Results

Aparatermes thornatus Pinzon and Scheffrahn sp. nov. 2018 Imago. Unknown

Worker (Table 1, Figs. 1-3D).

Fig. 2.

Aparatermes thornatus worker gut: (A) dorsal; (B) lateral right; (C) ventral; (D) lateral left views. Abbreviations of gut sections: C = crop, EVS = enteric valve seating, M = mesenteron, MT = mesenteric tongue, P1-P5 = proctodeal segments.

Fig. 3.

Aparatermes enteric valve cushions: (A) A. cingulatus; (B) A. abbreviatus; (C) A. silvestrii; (D) A. thornatus.

Discussion

The use of enteric valve armature and gene sequences is becoming particularly useful to separate New World soldierless Apicotermitinae genera and species (Borguinon et al. 2013, 2016a; Carrijo et al. 2015; Scheffrahn et al. 2017). Besides coloration and size differences of the worker, A. thornatus enteric valve armature possesses a conspicuous thorn on each of the cushions, whereas the other species vary in thorn number (e.g., A. cingulatus Bourguignon et al. 2013). Also, the reddish coloration and smaller size of A. thornatus is distinct from other species. In addition, COI gene sequences also support a strong distinction of A. thornatus from its sister species A. silvestrii.

Fig. 4.

Distribution of Aparatermes from University of Florida Termite Collection records.

Fig. 5.

Bayesian phylogeny of all described soldierless New World genera using the mitochondrial Cytochrome Oxidase subunit 1 COI barcode gene showing posterior probabilities. Tree rooted on terminal Heterotermes crinitus.

The results of our study support that A. thornatus and A. silvestrii should be separated in a new genus; however, given the low branch support recovered in the phylogeny, we prefer to not make any taxonomic change in genus level. Acioli and Constantino (2015) indicate that “a revision of the ‘silvestrii’ group is underway and will be published,” so it is believed that deeper discussions on the genera relationships should be made by this revision coming soon.