Updated classification of the phylum Parabasalia.

The phylum Parabasalia includes very diverse single-cell organisms that nevertheless share a distinctive set of morphological traits. Most are harmless or beneficial gut symbionts of animals, but some have turned into parasites in other body compartments, the most notorious example being Trichomonas vaginalis in humans. Parabasalians have garnered attention for their nutritional symbioses with termites, their modified anaerobic mitochondria (hydrogenosomes), their character evolution, and the wholly unique features of some species. The molecular revolution confirmed the monophyly of Parabasalia, but considerably changed our view of their internal relationships, prompting a comprehensive reclassification 14 years ago. This classification has remained authoritative for many subgroups despite a greatly expanded pool of available data, but the large number of species and sequences that have since come out allow for taxonomic refinements in certain lineages, which we undertake here. We aimed to introduce as little disruption as possible but at the same time ensure that most taxa are truly monophyletic, and that the larger clades are subdivided into meaningful units. In doing so, we also highlighted correlations between the phylogeny of parabasalians and that of their hosts.

Cryptotermespugnus (Blattodea, Isoptera, Kalotermitidae), a new drywood termite species from the Brazilian Caatinga dry forest and key to South American Cryptotermes Banks, 1909.

A new termite species, Cryptotermespugnussp. nov., is described from northeastern Brazil. The winged imago of C.pugnus is distinguished from most congeners by the lack of arolia and the multiple branches connecting the median vein to the radial sector. The soldier is unique among South American Cryptotermes by its cuboidal head capsule and very rugose postclypeus. The new species constitutes the fourteenth Cryptotermes species on the continent for which we provide a key to soldiers.

Diminishing the taxonomic gap in the neotropical soldierless termites: descriptions of four new genera and a new Anoplotermes species (Isoptera, Termitidae, Apicotermitinae).

The neotropical Apicotermitinae is a common and widespread clade of mostly soil-feeding soldierless termites. With few exceptions, species of this group were originally assigned to the genus Anoplotermes Müller, 1873. The application of internal worker morphology coupled with genetic sequencing has recently shed light on the true diversity of this subfamily. Herein, Anoplotermessusanae Scheffrahn, Carrijo & Castro, sp. nov. and four new species in four new genera are described: Hirsutitermeskanzakii Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov., Krecekitermesdaironi Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov., Mangolditermescurveileum Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov., and Ourissotermesgiblinorum Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov. Worker descriptions are based mainly on worker gut morphology, including the enteric valve, while imagoes were described based on external characters. A Bayesian phylogenetic tree of New World Apicotermitinae was constructed using the complete mitogenome to infer genera relationships and corroborate the taxonomic decisions. Distribution maps and a dichotomic key to the known Neotropical Apicotermitinae genera are provided.

New Parabasalia symbionts Snyderella spp. and Daimonympha gen. nov. from South American Rugitermes termites and the parallel evolution of a cell with a rotating "head".

Most Parabasalia are symbionts in the hindgut of "lower" (non-Termitidae) termites, where they widely vary in morphology and degree of morphological complexity. Large and complex cells in the class Cristamonadea evolved by replicating a fundamental unit, the karyomastigont, in various ways. We describe here four new species of Calonymphidae (Cristamonadea) from Rugitermes hosts, assigned to the genus Snyderella based on diagnostic features (including the karyomastigont pattern) and molecular phylogeny. We also report a new genus of Calonymphidae, Daimonympha, from Rugitermes laticollis. Daimonympha's morphology does not match that of any known Parabasalia, and its SSU rRNA gene sequence corroborates this distinction. Daimonympha does however share a puzzling feature with a few previously described, but distantly related, Cristamonadea: a rapid, smooth, and continuous rotation of the anterior end of the cell, including the many karyomastigont nuclei. The function of this rotatory movement, the cellular mechanisms enabling it, and the way the cell deals with the consequent cell membrane shear, are all unknown. "Rotating wheel" structures are famously rare in biology, with prokaryotic flagella being the main exception; these mysterious spinning cells found only among Parabasalia are another, far less understood, example.

Chasitermespax, a new genus and species of soldierless termite (Termitidae, Apicotermitinae) from the island of Trinidad.

Chasitermespax Scheffrahn & Carrijo gen. et sp. nov. is described from workers collected from a single colony in the Northern Range of Trinidad. The shape and texture of the unsclerotized enteric valve, tubular shape of the enteric valve seating, and prominent spherical mesenteric tongue of C.pax are the diagnostic characters for both the genus and species. A Bayesian phylogenetic analysis using the COI gene and including all neotropical Apicotermitinae genera described to date supports the new genus as a distinct terminal.

Amitermes californicus Banks, 1920 (Isoptera, Termitidae, Termitinae) resurrected after ninety years of synonymy and A. floridensis Scheffrahn, 1989 synonymized into A. wheeleri (Desneux, 1906).

Amitermes californicus Banks, 1920 was described from southern California and southern Arizona but was later synonymized with A. wheeleri (Desneux, 1906) from Texas. Examination of material across the southwestern Nearctic and Mexico revealed that both are good species that are easily separated by the soldier mandibles. Amitermes floridensis Scheffrahn, 1989 is now a synonym of A. wheeleri. The establishment of A. wheeleri (=floridensis) in Florida is suggested to be the result of the ornamental palm trade from the southwestern United States. New collection records show that A. wheeleri has not been found in California.

Comparison of traditional and DNA metabarcoding samples for monitoring tropical soil arthropods (Formicidae, Collembola and Isoptera).

The soil fauna of the tropics remains one of the least known components of the biosphere. Long-term monitoring of this fauna is hampered by the lack of taxonomic expertise and funding. These obstacles may potentially be lifted with DNA metabarcoding. To validate this approach, we studied the ants, springtails and termites of 100 paired soil samples from Barro Colorado Island, Panama. The fauna was extracted with Berlese-Tullgren funnels and then either sorted with traditional taxonomy and known, individual DNA barcodes ("traditional samples") or processed with metabarcoding ("metabarcoding samples"). We detected 49 ant, 37 springtail and 34 termite species with 3.46 million reads of the COI gene, at a mean sequence length of 233 bp. Traditional identification yielded 80, 111 and 15 species of ants, springtails and termites, respectively; 98%, 37% and 100% of these species had a Barcode Index Number (BIN) allowing for direct comparison with metabarcoding. Ants were best surveyed through traditional methods, termites were better detected by metabarcoding, and springtails were equally well detected by both techniques. Species richness was underestimated, and faunal composition was different in metabarcoding samples, mostly because 37% of ant species were not detected. The prevalence of species in metabarcoding samples increased with their abundance in traditional samples, and seasonal shifts in species prevalence and faunal composition were similar between traditional and metabarcoding samples. Probable false positive and negative species records were reasonably low (13-18% of common species). We conclude that metabarcoding of samples extracted with Berlese-Tullgren funnels appear suitable for the long-term monitoring of termites and springtails in tropical rainforests. For ants, metabarcoding schemes should be complemented by additional samples of alates from Malaise or light traps.

Using ultraconserved elements to reconstruct the termite tree of life.

The phylogenetic history of termites has been investigated using mitochondrial genomes and transcriptomes. However, both sets of markers have specific limitations. Mitochondrial genomes represent a single genetic marker likely to yield phylogenetic trees presenting incongruences with species trees, and transcriptomes can only be obtained from well-preserved samples. In contrast, ultraconserved elements (UCEs) include a great many independent markers that can be retrieved from poorly preserved samples. Here, we designed termite-specific baits targeting 50,616 UCE loci. We tested our UCE bait set on 42 samples of termites and three samples of Cryptocercus, for which we generated low-coverage highly-fragmented genome assemblies and successfully extracted in silico between 3,426 to 42,860 non-duplicated UCEs per sample. Our maximum likelihood phylogenetic tree, reconstructed using the 5,934 UCE loci retrieved from upward of 75% of samples, was congruent with transcriptome-based phylogenies, demonstrating that our UCE bait set is reliable and phylogenetically informative. Combined with non-destructive DNA extraction protocols, our UCE bait set provides the tool needed to carry out a global taxonomic revision of termites based on poorly preserved specimens such as old museum samples. The Termite UCE database is maintained at: https://github.com/oist/TER-UCE-DB/.

Caetetermes fontesi, a new nasutiform termite (Isoptera: Termitidae: Nasutitermitinae) from French Guiana.

Caetetermes fontesi sp. nov. is described from soldiers, workers, and winged imagos collected in French Guiana. Soldiers of C. fontesi are distinguished from Caetetermes taquarussu Fontes 1981, until now a monotypic genus, by their larger size, deeper coloration, and shorter and thicker nasus. The imago of C. fontesi is larger and the enteric valve of the dimorphic C. fontesi workers have larger cushions with more and longer spines than C. taquarussu. Worker dimorphism for Neotropical nasutitermitinae is discussed.

Revised systematic position of Nasutitermes brevipilus Emerson, 1925 (Isoptera: Termitidae: Nasutitermitinae) and the designation of Hyleotermes gen. nov.

A new monotypic nasute termite genus, Hyleotermes gen. nov., is proposed for Nasutitermes brevipilus Emerson, 1925. Hyleotermes brevipilus, comb. nov., is redescribed and illustrated based on the morphology of the imago, soldier, and worker castes. It is expanded into Amazonia. The soldier of Hyleotermes differs from that of Nasutitermes Dudley, 1890 in that the former has a long and cylindrical nasus and the head capsule lacks long setae and is covered with microscopic setae. Unlike the worker of Nasutitermes, the Hyleotermes worker has a short mixed segment and an enteric valve is adorned with narrow spines on conical bases. The phylogenetic position of H. brevipilus comb nov., is reconstructed based on a dataset with two mitochondrial markers (COI and 16SrRNA) for 36 terminals, under maximum likelihood and Bayesian inference. Results corroborate that this species is unrelated to Nasutitermes and should be excluded from the genus.

Ebogotermes raphaeli, new genus and new species, an African soldierless termite described from the worker caste (Isoptera, Termitidae, Apicotermitinae).

Ebogotermes raphaeli gen. n. sp. n., is described from workers collected in Cameroon. This soil-feeding termite is the largest soldierless termite from central Africa and aligns with the Anoplotermes subgroup. The enteric valve armature is weakly armed and, as with most apicotermitine species, is uniquely diagnostic.

Rugitermesursulae (Isoptera, Kalotermitidae), a new drywood termite from the Caribbean coast of Colombia.

Rugitermesursulae sp. nov. is described from a sample collected inside a dead branch in a tropical dry forest of Colombia's Caribbean coast using molecular information and external morphological characters of the imago and soldier castes. Rugitermesursulae sp. nov. soldiers and imagoes are the smallest among all described Rugitermes species. The imago's head capsule coloration is dark castaneous, while the pronotum is contrastingly pale yellow. Our description includes soldier characters, such as subflangular elevation and shape of the antennal sockets, that can help in identification of samples lacking imagoes.

The termite genus Glyptotermes (Isoptera, Kalotermitidae) from Paraguay.

A 2012 termite expedition yielded the first species of Glyptotermes known from Paraguay, G.hickmani sp. nov. and G.canellae (Müller, 1873), the latter previously known from Argentina and Brazil. Both are described based on the soldier and imago castes.

Characterization of new cristamonad species from kalotermitid termites including a novel genus, Runanympha.

Cristamonadea is a large class of parabasalian protists that reside in the hindguts of wood-feeding insects, where they play an essential role in the digestion of lignocellulose. This group of symbionts boasts an impressive array of complex morphological characteristics, many of which have evolved multiple times independently. However, their diversity is understudied and molecular data remain scarce. Here we describe seven new species of cristamonad symbionts from Comatermes, Calcaritermes, and Rugitermes termites from Peru and Ecuador. To classify these new species, we examined cells by light and scanning electron microscopy, sequenced the symbiont small subunit ribosomal RNA (rRNA) genes, and carried out barcoding of the mitochondrial large subunit rRNA gene of the hosts to confirm host identification. Based on these data, five of the symbionts characterized here represent new species within described genera: Devescovina sapara n. sp., Devescovina aymara n. sp., Macrotrichomonas ashaninka n. sp., Macrotrichomonas secoya n. sp., and Macrotrichomonas yanesha n. sp. Additionally, two symbionts with overall morphological characteristics similar to the poorly-studied and probably polyphyletic 'joeniid' Parabasalia are classified in a new genus Runanympha n. gen.: Runanympha illapa n. sp., and Runanympha pacha n. sp.

Cryptotermes camelus (Isoptera: Kalotermitidae), a new drywood termite species from the Bolivian Chaco.

Cryptotermes Banks, 1906 is the third most diverse kalotermitid genus worldwide after Glyptotermes Froggatt, 1897 and Neotermes Holmgren, 1911, with its greatest diversity found in the Neotropics (Krishna et al. 2013a). Furthermore, the greatest number of species of Cryptotermes are known from the Caribbean Basin (Scheffrahn Krecek 1999, Casala et al. 2016, Scheffrahn 2019). Although Araujo (1977) and Bacchus (1987) list Cryptotermes domesticus (Haviland, 1898) from Trinidad (treated as mainland) and Panama, respectively, Scheffrahn Krecek (1999) and Scheffrahn et al. (2009) doubt the existence of this Asian species in the New World. Without C. domesticus, the total extant Neotropical diversity of Cryptotermes is 29 endemic and three exotic species (Constantino 2020).

Limited evidence of C4 plant consumption in mound building Macrotermes termites from savanna woodland chimpanzee sites.

Stable isotope analysis is an increasingly used molecular tool to reconstruct the diet and ecology of elusive primates such as unhabituated chimpanzees. The consumption of C4 plant feeding termites by chimpanzees may partly explain the relatively high carbon isotope values reported for some chimpanzee communities. However, the modest availability of termite isotope data as well as the diversity and cryptic ecology of termites potentially consumed by chimpanzees obscures our ability to assess the plausibility of these termites as a C4 resource. Here we report the carbon and nitrogen isotope values from 79 Macrotermes termite samples from six savanna woodland chimpanzee research sites across equatorial Africa. Using mixing models, we estimated the proportion of Macrotermes C4 plant consumption across savanna woodland sites. Additionally, we tested for isotopic differences between termite colonies in different vegetation types and between the social castes within the same colony in a subset of 47 samples from 12 mounds. We found that Macrotermes carbon isotope values were indistinguishable from those of C3 plants. Only 5 to 15% of Macrotermes diets were comprised of C4 plants across sites, suggesting that they cannot be considered a C4 food resource substantially influencing the isotope signatures of consumers. In the Macrotermes subsample, vegetation type and caste were significantly correlated with termite carbon values, but not with nitrogen isotope values. Large Macrotermes soldiers, preferentially consumed by chimpanzees, had comparably low carbon isotope values relative to other termite castes. We conclude that Macrotermes consumption is unlikely to result in high carbon isotope values in either extant chimpanzees or fossil hominins.

Three new species of Rugitermes (Isoptera, Kalotermitidae) from Peru and Bolivia.

The soldier of Rugitermes aridus sp. nov. is described from a xeric, termite-depauperate region of central Peru. Rugitermes rufus sp. nov. and R. volcanensis sp. nov. are described from soldiers and dealated imagos collected in a mesic forest of Amboró National Park in western Bolivia. The imago of R. rufus is unique among all described Rugitermes species in that the head capsule is reddish orange and the pronotum is brown. The imago head and pronotum are both brown in R. volcanensis. A phylogenetic and GMYC barcode analyses were performed with the COI gene. These analyses confirmed the three new species and revealed a high undescribed diversity of Rugitermes in the New World.

Corrigendum: 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.

[This corrects the article DOI: 10.3897/zookeys.748.24253.].

Gastrotermes spinatus gen. n. sp. n., an African soil-feeding termite described from the worker caste (Isoptera, Termitidae, Apicotermitidae).

Gastrotermes spinatus gen. n. sp. n is described from workers of a single foraging group collected in Cameroon. This soil-feeding termite aligns with the Labidotermes subgroup (Apicotermes group) because of its non-protruding and symmetrical enteric valve armature, its short P1, and its globular P3a. An asymmetrical field of robust sclerotized spines at the opening of the P3a is unique among the other Labidotermes subgroup genera.

Rugitermes tinto: A new termite (Isoptera, Kalotermitidae) from the Andean region of Colombia.

The imago and soldier castes of a new Rugitermes Holmgren, 1911 species, R. tinto sp. nov. are described. It is the ninth species of Rugitermes from South America and the first record of this genus from Colombia. Unlike its congeners, the soldier of R. tinto has very dark head capsule pigmentation and acute protuberances projecting from frontolateral ridges.