Arceotermes hospitis Engel & Jiang, 2021

JIANG, RI-XIN, ZHANG, HONG-RUI, ELDREDGE, K. TARO, SONG, XIAO-BIN, LI, YAN-DA, TIHELKA, ERIK, HUANG, DI-YING, WANG, SHUO, ENGEL, MICHAEL S. & CAI, CHEN-YANG, 2021, Further evidence of Cretaceous termitophily: Description of new termite hosts of the trichopseniine Cretotrichopsenius (Coleoptera: Staphylinidae), with emendations to the classification of lower termites (Isoptera), Palaeoentomology 4 (4), pp. 374-389 : 381-382

Arceotermes hospitis Engel & Jiang , sp. nov.

( Figs 1A, B , 5 , 6 )

Holotype. Holotype soldier, QUST-INSECT-0015 . In mid-Cretaceous amber from Kachin Province, northern Myanmar. Deposited in the College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China .

Etymology. The specific epithet is taken from the Latin term hospitis , meaning, “host”, and refers to the hosting relationship between these termites and their inquilines, C. burmiticus .

Diagnosis. As for the genus (vide supra).

Description. Soldier:Total body length(as preserved) 5.00 mm; head enlarged, subrectangular, longer than wide, head length (excluding mandibles) 2.08 mm, maximum width 1.83 mm, chestnut brown, with virtually no setae, remainder of body with sparsely scattered, fine, suberect setae; head not dorsoventrally compressed, slightly wider than pronotum, lateral sides roughly parallel, posterolateral angles not tumid, lateral surface without stridulatory file, posterior border gently and broadly convex; fontanelle absent; labrum longer than wide, projecting over about 0.75× mandibular length, labrum length 0.55 mm, width 0.52 mm; anteclypeus pale (contrasting against darker coloration of labrum and postclypeus), flat, transverse, subequal in length to postclypeus; postclypeus transverse, comparatively flat; clypeus flanked by small, shallow lobes lateral to each lobe overhanding antennal insertion (as in soldiers of Archotermopsidae ); mandibles heavily sclerotized, approximately equal in size and length, left mandible length 0.97 mm, slightly overlapping apically, elongate, extending well beyond apex of labrum, gently bent ventrad apically; dentition prominent, with two right marginal teeth and three left marginal teeth; right marginal teeth broad, apical teeth long, pointed, curved; subsidiary tooth lacking; compound eyes absent; antenna with 17 moniliform articles; weak occipital carina present anteriorly, disappearing by tangent with widest point of postmentum; postmentum greatly widened anteriorly, somewhat spatulate in form, lateral margins concave, tapering posteriorly.

Pronotum broad, about as wide as head, anterior margin broadly and gently concave, lateral margins faintly convex, roughly parallel, posterolaterally broadly rounded, posterior border weakly convex, surface flat. Procoxa without carina; tibial spur formula 3-3-?; tarsi tetramerous; pretarsal claws simple; arolium absent; profemur 1.33 mm, protibia length 0.83 mm; protarsus length 0.35 mm.

Abdomen damaged as preserved.

Figures

FIGURE 1. Mid-Cretaceous termites with their putative rove beetle termitophiles. A, Arceotermes hospitis gen. et sp. nov. and Cretotrichopsenius burmiticus Cai et al., 2017a (QUST-INSECT-0015). B, Tanytermitalis philetaerus gen. et sp. nov. and C. burmiticus (NIGP174707). C, The entire amber piece of QUST-INSECT-0015. D, The entire amber piece of NIGP174707. Scale bars = 1 mm in A & C; 2 mm in B; 10 mm in D.

FIGURE 5. Holotype of Arceotermes hospitis Engel & Jiang, gen. et sp. nov., soldier (QUST-INSECT-0015). A, Ventral view of head, green fluorescence light source. B, Ventral view of head, with white light. C, Detail of antenna, green fluorescence light source. D, Detail of antenna, white light. E, Protarsus, ventral view, green fluorescence light source. F, Protarsus, profile, green fluorescence light source. Scale bars = 1 mm in A–D; 250 μm in E and F.

FIGURE 6. Mandibular dentition of Arceotermes hospitis Engel & Jiang, gen. et sp. nov., soldier. A, Dorsal view of head. B, Ventral view of head. C, Line drawing detail of mandibular dentition; LA = left apical; LM = left marginal; RA = right apical; RM = right marginal. Scale bars = 1 mm in A and B).