Research Article |
Corresponding author: Rudolf H. Scheffrahn ( rhsc@ufl.edu ) Academic editor: Pavel Stoev
© 2018 Rudolf H. Scheffrahn, Thomas Bourguignon, Pierre Dieudonné Akama, David Sillam-Dussès, Jan Šobotník.
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:
Scheffrahn RH, Bourguignon T, Akama PD, Sillam-Dussès D, Šobotník J (2018) Roisinitermes ebogoensis gen. & sp. n., an outstanding drywood termite with snapping soldiers from Cameroon (Isoptera, Kalotermitidae). ZooKeys 787: 91-105. https://doi.org/10.3897/zookeys.787.28195
|
Termites have developed a wide array of defensive mechanisms. One of them is the mandibulate soldier caste that crushes or pierces their enemies. However, in several lineages of Termitinae, soldiers have long and slender mandibles that cannot bite but, instead, snap and deliver powerful strikes to their opponents. Here, we use morphological and molecular evidence to describe Roisinitermes ebogoensis Scheffrahn, gen. & sp. n. from near Mbalmayo, Cameroon. Soldiers of R. ebogoensis are unique among all other kalotermitid soldiers in that they possess snapping mandibles. The imago of R. ebogoensis is also easily distinguished from all other Kalotermitidae by the lack of ocelli. Our study reveals a new case of parallel evolution of snapping mandibles in termites, a complex apparatus responsible of one of the fastest biological acceleration rates measured to date.
Ethiopian Region, mandibles, ocellus, taxonomy
Termites are extremely abundant (
Soldiers are specialized sterile colony defenders possessing exaggerated morphology of the head and mandibles (
The monophyletic family Kalotermitidae (
The monumental revision of the Kalotermitidae by
Images of individuals were taken as multi-layer montages using a Leica M205C stereomicroscope with a Leica DFC 425 module run with Leica Application Suite software version 3. Preserved specimens, stored in 85% ethanol, were positioned in a transparent petri dish filled with Purell hand sanitizer (70% EtOH). Measurements (Tables
DNA was extracted from five individuals of R. ebogoensis, after removal of the digestive tract. The full mitochondrial genome was amplified with TaKaRa LA Taq in two long PCR reactions using primers specifically designed for termites (
We used the mitochondrial genomes of ten species of Kalotermitidae, including one sample of Roisinitermes ebogoensis sequenced in this study. We used four non-Kalotermitidae termite species as outgroups to root the tree: Zootermopsis angusticollis, Hodotermopsis sjostedti, Coptotermes sjostedti, and Termitogeton planus. All mitochondrial genomes, except that of R. ebogoensis, have been published recently (Suppl. material
We reconstructed phylogenetic trees using Maximum Likelihood and Bayesian approaches. We ran the analyses twice, once with the third codon position included, and once without third codon position. The Bayesian phylogenies were implemented in MrBayes 3.2 (
Our phylogenetic analyses supported the monophyly of Kalotermitidae (Figure
Phylogenetic tree of Kalotermitidae based on full mitochondrial genomes. The tree depicted was reconstructed with RAxML using the data matrix without third codon position. Node labels are the Maximum Likelihood bootstrap supports and the Bayesian posterior probabilities in the following order, from left to right: posterior probability of the analysis with third codon position included, posterior probability of the analysis without third codon position, bootstrap support of the analysis with third codon position included, bootstrap support of the analysis without third codon position, *indicates 100% bootstrap support and 1.0 posterior probability for all four analyses.
Roisinitermes ebogoensis Scheffrahn sp. n.
Ocelli not visible either by pigmentation or cuticular protrusion (Figure
The lack of visible ocelli is unique among all other Kalotermitidae. In
Monomorphic (Figs
Stick-like mandibles unique among all other kalotermitid soldiers. In
The genus is named in honor of Dr. Yves Roisin for his many contributions to the study of termites.
Holotype. Soldier from colony UF no. AFR3327. CAMEROON: Ebogo II, (+3.37723N, +11.46135E), 647 m elev., 18FEB18, col. Raphael Onana, AFR3327 ca. 500 alates, 50 soldiers, and many pseudergates, nymphs, larvae, and eggs. Paratypes. CAMEROON, Ebogo II (+3.38273N, +11.46190E), 664 m elev., 10DEC2016, col. Jan Šobotník and collaborators, AFR2982 4 soldiers (1 damaged), one female dealate, and 46 brachypterous nymphs.
See generic diagnosis above.
Winged Imago (Figure
Measurements (mm) of Roisinitermes ebogoensis alates from a single colony.
Males (n=6) | Females (n=6) | |||||
---|---|---|---|---|---|---|
Measurement | max | min | mean | max | min | mean |
Head max. width | 1.05 | 0.95 | 1.00 | 1.05 | 1.00 | 1.03 |
Pronotum max. width | 1.00 | 0.89 | 0.96 | 1.05 | 0.93 | 1.01 |
No. antennal articles | 15 | 14 | 14.67 | 17.00 | 14.00 | 15.17 |
Max diam. eye | 0.40 | 0.32 | 0.36 | 0.39 | 0.35 | 0.37 |
Body length with wings | 9.63 | 8.63 | 9.10 | 9.88 | 9.50 | 9.65 |
Fore wing length (suture to tip) | 7.50 | 6.80 | 7.20 | 7.80 | 7.20 | 7.43 |
Soldier (Figs
Measurements of Roisinitermes ebogoensis soldier (n=17 from two colonies).
Measurement | Max | Min | Mean |
---|---|---|---|
Head length to lateral mandible base | 1.92 | 1.60 | 1.79 |
Head width, maximum | 1.28 | 1.18 | 1.22 |
Head height with gula, max. | 1.08 | 0.92 | 1.00 |
Pronotum length | 0.70 | 0.56 | 0.65 |
Pronotum width | 1.18 | 1.05 | 1.13 |
No. antennal articles | 14 | 10 | 12.70 |
Left mandible width @ basal humps | 0.35 | 0.21 | 0.26 |
Left mandible width @ middle | 0.18 | 0.16 | 0.17 |
Max. diam. eye | 0.26 | 0.18 | 0.21 |
Length left mandible from condyle (ventral) | 1.78 | 1.46 | 1.66 |
Brachypterous nymph (Fig.
The type colony of R. ebogoensis was collected in the forest on an island in the Nyong River near the Ebogo II village. The colony lived in a relatively thin (3 cm) and long (over 3 m) broad-leaf tree branch suspended from the canopy approximately 2 m above the ground. The colony contained roughly 2,000 members. A second colony of R. ebogoensis was collected in a nearly pristine rain forest near the village of Ebogo II. The colony was taken from a dead liana branch (ca. 15 mm diam.) hanging from the canopy at a height of approx. 1 m above the ground. Liana stems have been generally overlooked as a colonization site for Kalotermitidae (
The species is named for the village of Ebogo II, the type locality for this termite.
Kalotermitids inhabit a single woody item and are largely unable to move to a new food source once the original is exhausted. The lone exception is Paraneotermes simplicicornis that builds underground galleries connecting several wood pieces (
Our phylogenetic analyses consistently placed Roisinitermes on a long branch, next to N. insularis. Neotermes insularis is a large termite species from Northern Australia with soldiers endowed with biting mandibles of crushing type. The smaller Roisinitermes shares no obvious similarity with N. insularis, supporting its generic status. Currently, the number of mitochondrial genomes available for Kalotermitidae is limited to a handful of genera, and there is a possibility that future phylogenetic analyses will support affinities between Roisinitermes and yet-to-be sampled taxa. In any case, the highly unusual morphology of Roisinitermes suggests that it shares no close relatives among modern Kalotermitidae. Future studies should focus on whether the mechanisms used by soldiers of Roisinitermes to snap are like those of the distantly related Termitinae.
The authors thank Eliška Cintulová, Crystal Clitheroe and Barbora Křížková for assistance on R. ebogoensis full mitochondrial genome sequencing. J.Š. is grateful to Ebogo II inhabitants for their help during the fieldwork, and for helping saving the Ebogo forest for future generations. J.Š. and D.S.-D. thank Aleš Buček, František Jůna, and Margot Archambeu for their hard work during the field campaigns. The field work was supported by the Czech Science Foundation (project no. 16-05318S), by the Internal Grant Agency of Faculty of Forestry and Wood Sciences, CULS (IGA No. A_27_18) and by the Grand Agency of the Czech University of Life Sciences (CIGA No. 20184307).
Table S1