Research Article |
Corresponding author: Daniel Castro ( danielkaz80@gmail.com ) Corresponding author: Rudolf H. Scheffrahn ( rhsc@ufl.edu ) Academic editor: Dominic Evangelista
© 2018 Daniel Castro, Rudolf H. Scheffrahn, Tiago F. Carrijo.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Castro D, Scheffrahn RH, Carrijo TF (2018) Echinotermes biriba, a new genus and species of soldierless termite from the Colombian and Peruvian Amazon (Termitidae, Apicotermitinae). ZooKeys 748: 21-30. https://doi.org/10.3897/zookeys.748.24253
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A new Apicotermitinae genus and species Echinotermes biriba is described from workers collected on the Andean-Amazon Piedmont in Colombia and Peru. The enteric valve armature of Echinotermes biriba Castro & Scheffrahn, gen. et sp. n. is a remarkably diagnostic character. A Bayesian phylogenetic analysis using the COI gene and including all other Neotropical Apicotermitinae genera, supports the new genus as a distinct terminal.
Anoplotermes-group, enteric valve, Neotropic, taxonomy
The soldierless termites of Amazonia form a dominant group and comprise more than 30% of the termite diversity in neotropical assemblages (
Currently, 13 genera and 52 species of Apicotermitinae are known from the Neotropical region (
In this paper Echinotermes biriba gen. n. et sp. n. is described based on the morphology of the worker caste and molecular data.
The specimens were collected and preserved in 75% or 85% ethanol. The dissection of the enteric valve (EV) was done by removing the P2 tube from the worker’s gut and then expelling all the food particles by means of controlled pressure. The tube was immersed in a PVA medium to completely detach the EV from surrounding muscle tissue and cut longitudinally to splay open the EV for mounting in the medium. The mandibles were also submerged in PVA medium. The terminology used for the worker gut follows
The COI sequence of E. biriba was obtained by DNA extraction and PCR performed by the Canadian Centre for DNA Barcoding following standard high-throughput protocols (
A gene tree was created under Bayesian Inference (BI) using the COI gene. In addition to the sequence of E. biriba, a total of 48 GenBank sequences were used: 34 sequences of neotropical Apicotermitinae (21 species, 13 genera), eight non neotropical Apicotermitinae genera, five non-apicotermitine Termitidae, and one Rhinotermitidae, (Heterotermes crinitus) as the outgroup. Sequences were aligned under MUSCLE algorithm implemented in Geneious v6.1.6 (Biomatters Ltd., Auckland, New Zealand). Substitution model used (GTR+I+G) was selected through the Akaike Information Criterion (AIC) with the software jModelTest2 (
Echinotermes biriba sp. n.
Imago. Unknown.
(Fig.
Worker of Echinotermes biriba sp. n.: A dorsal and lateral views of head and pronotum B mandibles C right fore-tibia D digestive tube from left to right: dorsal, right, ventral and left views. Abbreviations: C = crop, EVS = enteric valve seating, MS = mesenteron, MT = mesenteric tongue, P1–P5 = proctodeal segments.
Fore-tibia moderately inflated (Fig.
Digestive tube (Fig.
Worker enteric valve of Echinotermes biriba sp. n. A Spliced mount B whole mount, showing in situ position of armature. Note the filamentous bacteria attached to the spines. The trilobed seating anterior to the spines (removed in this preparation) is full of bacteria and devoid of food particles, referred by
The crop of E. biriba is unusually large and the enteric valve armature, consisting of six spherical pectinate pads, is unique among all apicotermitine genera.
Mandibles of Rubeotermes jheringi and Humutermes krishnai are very similar to E. biriba, but the first marginal teeth of E. biriba are less prominent that those two genera. The diagnostic character of E. biriba is the enteric valve armature which is also spiked in the Humutermes enteric valve (EV) but in E. biriba the EVarmature is spherical while in Humutermes it is rather flat. Humutermes species are smaller than Echinotermes. The enteric valve of Grigiotermes is composed of six uniform pectinate plates, while in Patawatermes the uniform plates are hemispherical.
From the Latin Echino, meaning spiny, describing the EV armature.
Worker from colony CATAC 2736.
COLOMBIA: Caquetá, Belén de los Andaquíes (1.60794, -75.88683).
PERU: Pasco, Oxapampa, Chatarra forest, (-10.51303, -75.07276), 24/05/2014, 556 m, 14 workers (UF no. PU 144). Additional material: COLOMBIA: Caquetá, Belén de los Andaquíes, Camino Andaquí (1.60794, -75.88683), 31/01/2017, 625 m, 10 workers (CATAC 2736).
(Fig.
Measurements (mm) of ten workers from two colonies of Echinotermes biriba sp. n.
Holotype | PU144 | CATAC2736 | |||
---|---|---|---|---|---|
Range | Mean | Range | Mean | ||
Max Head Width | 0.74 | 0.77–0.74 | 0.75 | 0.83–0.74 | 0.78 |
Pronotum Width | 0.44 | 0.49–0.46 | 0.48 | 0.44–0.55 | 0.51 |
Hind Tibia Length | 0.57 | 0.53–0.44 | 0.48 | 0.61–0.55 | 0.57 |
Fore Tibia Length | 0.48 | 0.44–0.35 | 0.41 | 0.49–0.43 | 0.46 |
Fore Tibia Width | 0.13 | 0.14–0.11 | 0.12 | 0.14–0.11 | 0.12 |
Fore Tibia Width: Length Ratio | 0.27 | 0.36- 0.24 | 0.30 | 0.23–0.28 | 0.26 |
Unique armature of EV composed of alternating larger and smaller spheroids covered with robust spines.
See genus remarks above.
In Colombia, E. biriba foragers were collected in the same soil sample (0-10 cm depth) with Longustitermes manni. Gut contents confirm that E. biriba feeds on soil organic matter. This species is only known from the Chatarra forest in the southern Peruvian Amazon, and in a mature secondary forest in the northern Colombian Amazon (Fig.
The gene tree recovered the Neotropical Apicotermitinae (NA) as monophyletic, however, the position of Echinotermes biriba inside this clade could not be established with this single gene. The low posterior probability of almost every first branching clades in the NA group should be interpreted as a big polytomy, and the new genus as a branch in this polytomy, just as most of the other NA genera (Fig.
The species name is due to the resemblance of the EV armature with the Amazonian fruit Rollinia mucosa (Jacq.) Baill. which is known as “biriba” in the region.
Neotropical soldierless termites have been a taxonomic problem to a large extent because enteric valve (EV) morphology was overlooked.
The Amazon forest contains the greatest diversity of New World termites (
We want to thank to the Colciencias, Instituto Amazónico de Investigaciones Científicas SINCHI and Expedición BIO project for the financial support in Colombian Amazon. We also thank to Dr. Clara P. Peña-Venegas for coordinating the soil component at SINCHI and for her logistic support on field trips. We heartily thank the reviewers for their help in improving the paper.