Falsotithassa Pic, 1934

Aalbu, Rolf L., Kanda, Kojun, Merkl, Otto, Ivie, Michael A. & Johnston, M. Andrew, 2023, Reconstitution of some tribes and genera of Lagriinae (Coleoptera, Tenebrionidae), ZooKeys 1172, pp. 155-202 : 155

Genus Falsotithassa Pic, 1934

Figs 74-78

Falsotithassa Pic, 1934: 18. Type species: Falsotithassa sumatrana Pic, 1934.

Note.

Falsotithassa Pic, 1934 is transferred from Lupropini ( Lagriinae ) to Leiochrinini Lewis, 1894 ( Diaperinae ). Falsotithassa contains ten species of small Tenebrionidae distributed across the Indo-Malayan biogeographic region. In the original description of this genus, Pic noted its similarity to Tithassa , which in this present paper is classified in Prateini . Based on the ordering of the descriptions in Pic’s (1934) manuscript, and the placement of the descriptions of Falsotithassa between species of Anaedus ( Goniaderini ) and Tithassa , it can be inferred that Pic considered this genus to be closely related to these taxa, and therefore included in Lagriinae . Schawaller (2000) revised Falsotithassa , providing a detailed diagnosis for this genus, and synonymized Derispiolina Kaszab, 1979 which was originally described as a tentative member of the tribe Leiochrinini ( Kaszab 1979). In that study, Schawaller suggested that Falsotithassa belonged in Diaperini ( Diaperinae ), but in a later paper ( Schawaller 2007c) reinterpreted the same characters studied in his initial 2000 revision as supporting the placement of Falsotithassa in Lupropini . This placement is adopted in the recent generic catalog of Tenebrionidae ( Bouchard et al. 2021).

Examination of character states not discussed by Schawaller (2000, 2007c) and reinterpretation of female reproductive structures described in these papers support the exclusion of Falsotithassa from Lagriinae and supports its inclusion in Leiochrinini . The most evident character for excluding Falsotithassa from Lagriinae is the presence of complex sensoria on antennomeres 4-11 (Fig. 75 ); all Lagriinae have only simple antennal sensoria. Additionally, the abdominal defensive gland reservoirs have a lateral commissure joining the base of the left and right reservoir (Fig. 76 ). This arrangement is only known to occur in Leiochrinini and Nilionini ( Doyen et al. 1990; Matthews and Bouchard 2008). The main characters used by Schawaller (2000, 2007c) in placing Falsotithassa in Diaperini was the presence of a capsular spermatheca ("check valve"), a character that is only known to occur in Diaperini and Nilionini ( Tschinkel and Doyen 1980; Aloquio and Lopes-Andrade 2016). New dissections of specimens identified as Falsotithassa sumatrana by Schawaller, and matched with the holotype, show a large thin-walled balloon-like spermathecae (Figs 77 , 78 ). These are not the same as the capsular spermathecae present in Diaperini and Nilionini but are very similar to spermathecae illustrated for other species of Leiochrinini ( Doyen et al. 1990; Matthews and Bouchard 2008).

We transfer Falsotithassa to Leiochrinini based upon the three characters discussed above: (1) antennae with complex sensoria on antennomeres 4-11; (2) abdominal defensive gland reservoirs joined by lateral commissure; (3) female internal reproductive tract with large thin-walled spermathecae. Further support of this conclusion is provided by characters mentioned by Schawaller (2000), including internally open procoxal cavities and the female reproductive tract lacking a bursa copulatrix. However, Falsotithassa departs from the coccinellid-like appearance of all other current members of Leiochrinini and indeed is externally similar to members of Scaphidemini Reitter, 1922. The latter is presently defined by a strongly sclerotized T-shaped spermatheca and the defensive glands lacking a commissure ( Doyen et al. 1990; Matthews and Bouchard 2008) which preclude the placement of Falsotithassa therein. We hypothesize that the tribes Leiochrinini and Scaphidemini are likely closely related and should be reevaluated with respect to each other in future studies.

Figures

Figures 74 - 78. Dorsal habitus and structures of Falsotithassa sumatrana Pic, 1934. 74 Dorsal habitus of holotype 75 antennae of non-type specimen 76 defensive gland reservoirs 77 ovipositor 78 portion of spermatheca. Abbreviations: cas = compound antennal sensoria, dgr = defensive gland reservoir, lc = lateral commissure, goc 4 = fourth gonocoxite, gos = gonostylus, sp = spermatheca, sag = spermathecal accessory gland. Fig. 74 taken by Cristophe Rivier (MNHN). Scale bar: 1 mm.

Figures 68 - 73. Dorsal habitus and structures of Pseudesarcus Champion, 1913. 68 Dorsal habitus of Pseudesarcus villosus Champion, 1913, holotype 69 antennae of Pseudesarcus sp. 70 defensive gland reservoirs of P. villosus 71 ovipositor of P. villosus 72 female internal reproductive tract of Pseudesarcus sp. 73 details of spermatheca / spermathecal accessory gland complex of Pseudesarcus sp. Abbreviations: cas = compound antennal sensoria, dgr = defensive gland reservoir, par = paraprocts, goc = gonocoxites, gos = gonostyli, od = oviduct, bc = bursa copulatrix, cs = capsular spermatheca, sag = spermathecal accessory gland. Fig. 68 taken by Keita Matsumoto (NHMUK).