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| Karillantu gen. nov. in Koszela, Farinango et Żyła, 2025 |
Abstract
We describe a new genus of Paederinae rove beetles, Karillantu gen. nov., which occurs only in the Neotropics. The genus accommodates Lathrobium macrocephalum Sharp, 1876 as a type species Karillantu macrocephalus comb. nov., originally described more than 100 years ago. Intense surveys across museum collections allowed for describing eight new species: Karillantu amazonaensis sp. nov., Karillantu ecuadoriensis sp. nov., Karillantu lauretensis sp. nov., Karillantu napoensis sp. nov., Karillantu obidensis sp. nov., Karillantu paraensis sp. nov., Karillantu pastazaensis sp. nov., and Karillantu peruviensis sp. nov. We provide descriptions of the genus and species, a redescription of Karillantu macrocephalus comb. nov., an identification key, and a distribution map. To determine the sister-group relationships of Karillantu gen. nov., we conducted a phylogenetic analysis based on seven gene fragments, resulting in the largest Paederinae phylogeny up to date and a hypothesis about Karillantu gen. nov. placement. The analysis resolved the genus within the tribe Lathrobiini, nested in the informal clade of genera traditionally assigned to the subtribe Lathrobiina. We also provide information on the phylogenetic position of 17 newly sequenced taxa expanding our understanding of Paederinae relationships. The present research underscores the importance of museum collections in studying biodiversity of poorly-known groups, especially in the tropical regions.
molecular phylogeny, museum collections, Neotropics, Paederinae, rove beetles, South America, systematics, taxonomy
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| Head capsule of Karillantu macrocephalus (A–B). A, photo. B, schematic drawing. Scanning electronic micrographs of K. ecuadoriensis head (C), K. pastazaensis wall (D), and Karillantu spp. 1 punctures (E). Abbreviations: elev - elevation, pr - protrusions, setae: MS - mandibular, PCS - protrusion, PMS - postmarginal, POS - preocular, SAS - supraantennal. |
Subfamily Paederinae Fleming, 1821
Tribe Lathrobiini Laporte de Castelnau, 1835
Subtribe incertae sedis
Karillantu gen. nov.
Diagnosis: The genus can be easily differentiated from other Lathrobiini by the following combination of features: head large, equal to or wider than pronotum (except for K. pastazaensis and K. obidensis), with invaginated posterior median emargination, coarsely punctured, most densely on temples, with glabrous mid-line, maxillary palpomere 3 elongate, maxillary palpomere 4 conical, thinner than 3, pronotum anterior angles well developed, almost straight, with invaginated line in the middle; dense golden setation on inner side of protarsi; aedeagus with parameres reduced to two small lateral lobes.
Type species: Lathrobium macrocephalum Sharp, 1876.
Description: Body length from 5.35 to 12.6 mm. Coloration lighter or darker brown, appendages sometimes yellowish, setation golden-brown, protibia with gold setae on inner side.
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| Karillantu amazonaensis holotype, ♂ (A–J). A, habitus in dorsal view, scale bar: 1 mm. B, labrum. Abdominal segments, posterior margin schemes (C–F). C, tergite VII. D, tergite VIII. E, sternite VII. F, sternite VIII. Aedeagus (G–J), scale bar: 0.5 mm. G, parameral view. H, parameral view scheme. I, lateral view. J, lateral view scheme. |
Etymology: Karillantu /ˌkærɪˈd͡ʒɑːntuː/ derives from the Ecuadorian Kichwa language. It is a composite word comprising ‘Kari’, a prefix denoting strength or markedness, particularly in reference to the pronounced shape of the head, and ‘llantu’ signifying darkness, attributed to the dark coloration of individuals within the genus and the hidden generic status of K. macrocephalus. Gender: masculine.
Distribution: The genus occurs in the Amazon biome in different ecoregions of moist forests of the Amazon rainforest (Fig. 5).
Katarzyna Koszela, Karen Bonilla Farinango and Dagmara Żyła. 2025. Out of the Darkness - A New Genus of Paederinae from the Neotropics (Coleoptera: Staphylinidae) and its phylogenetic position. Zoological Journal of the Linnean Society. 204(3); zlaf071. DOI: doi.org/10.1093/zoolinnean/zlaf071 [31 July 2025]
