Phobeliina Ardoin, 1961, 2023

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

Subtribe Phobeliina Ardoin, 1961 stat. rev.

Figs 56 , 57 , 60 , 61 , 64

Type genus.

Phobelius Blanchard, 1842.

Note.

Phobelius (Fig. 56 ) contains 13 Neotropical species. The genus was included in the group “Phobéliides” by Lacordaire (1859) within the tribe Hétérotarsides along with Phymatestes , Anaedus , and Luprops . Subsequently, Ardoin (1961) included Phobeliina as a subtribe of Adeliini and transferred all genera except Phobelius to other groups. Matthews (1998), in his comprehensive review of Adeliini , noted that Phobelius exhibits characters consistent with Lagriini and that the only difference between Phobelius and other members of the tribe was that Phobelius did not have the elongate terminal antennomere typically found in Lagriini . Matthews further concluded that Phobelius should be included in a third subtribe (separate from Lagriina and Statirina ) in Lagriini . However, subsequent catalogus did not follow Matthews’ assessment, and Phobelius is currently included within Goniaderini with Phobeliina similarly synonymized under this tribe ( Bouchard et al. 2005, 2011, 2021; Bousquet et al. 2018).

In molecular phylogenetic studies that included Phobelius ( Kanda et al. 2015; Aalbu et al. 2017), the genus was recovered in a clade with Lagriini (Fig. 1 ), supporting Matthews’ conclusion. Lagriini (Figs 54-57 ) can be distinguished from other Lagriinae by the following characters: presence of abdominal defensive glands that open between abdominal sternites VII and VIII; pronotum with lateral margins absent or weakly impressed; antennae usually with terminal antennomeres elongate. Although Phobelius does not have elongate terminal antennomeres, they do have abdominal defensive glands and lack lateral pronotal margins.

Before this study, two subtribes of Lagriini were recognized, Lagriina and Statirina . The two subtribes can be distinguished based on differences in the prothorax. In Lagriina , the lobes of the hypomera meet behind the procoxae (Fig. 58 ) and, in Statirina , the lobes of the hypomera do not meet and are separated by the prosternum (Fig. 59 ). The prosternal process in Lagriina is thin and recessed between strongly projecting procoxae, sometimes resulting in the procoxal cavities appearing to be contiguous. In Statirina , the prosternal process forms a complete strip of cuticle, approximately ¼ the width of the procoxa, and clearly separates the coxae throughout their entire length. In addition to prothoracic characters, Lagriina tend to be broader bodied while Statirina tend to be more slender. The elongation of the terminal antennomere tends to be much more pronounced in Statirina , and in some Lagriina the terminal antennomere is nearly the same length as the penultimate antennomere.

As Matthews (1998) noted, Phobelius does not neatly fit within either of the two subtribes. Its prothorax (Fig. 60 ) resembles Statirina ; the lobes of the hypomera do not meet posterior to the coxae and the prosternal process is wide and not recessed as in Lagriina . The stout body (Fig. 56 ) is more like body forms seen in Lagriina . The terminal antennomere is also not particularly elongate in either males or females, at most only 1.5 times longer than the preceding one. The shape of the abdominal defensive gland reservoirs differs from both Lagriina and Statirina as well. In Phobelius , the gland reservoirs are large and conical, with wide openings (Fig. 64 ). In Lagriina and Statirina , the gland reservoirs are small, sometimes inconspicuous, and are widely separated (Figs 62 , 63 ).

We reinstate Phobeliina Ardoin, 1961 as a valid subtribe of Lagriini based upon the previous molecular phylogenetic analyses and morphological discussion presented above. We propose the following diagnosis of this lineage of Lagriini : body form stout; antennomeres stout, terminal antennomere not distinctly elongated in either sex; pronotum lacking lateral margin; procoxae separated by distinct prosternal process; hypomera extending mesally behind procoxae and both joined to prosternal process, not meeting each other; mesocoxae open; paired defensive glands present between abdominal sternites VII and VIII, glands large, conical.

Based upon our updated recognition of Phobeliina , we also tentatively include within it the genus Rhosaces Champion, 1889 (Figs 57 , 61 ). This monotypic genus was erected for Rhosaces clavipes Champion, 1889 and placed within Statirina where it has been treated ever since ( Blackwelder 1945; Bousquet et al. 2018; Bouchard et al. 2021), although Champion (1889) pointed out the strong differences in antennae (lacking an elongate terminal antennomere), a short epistoma, and a broadly rounded intercoxal process of the abdomen. All of the characters mentioned by Champion (1889) are shared with Phobelius , and the defensive glands, mesocoxal openings, and prothoracic characters similarly seem to unite these two genera. It is clear that Rhosaces does not fit within our concept of Lagriina , and it does adhere to our diagnosis of Phobeliina , and we look forward to future phylogenetic investigations that can more rigorously test the monophyly of this assemblage.

Figures

Figure 1. Phylogeny of Lagriinae from Aalbu et al. (2017) with revised generic names, tribal classification, and diagnostic morphological characters. Prev [ious]. Tribal Placement: COS = Cossyphini, BEL = Belopini, ADE = Adeliini, LAG = Lagriini, CHA = Chaerodini, LUP = Lupropini, GON = Goniaderini, PYC = Pycnocerini, LAE = Laenini. Defensive glands: location and number of abdominal defensive gland reservoirs: 8 / 9, paired = a pair of gland reservoirs with openings between abdominal sternites 8 and 9; 7 / 8, paired = a pair of gland reservoirs with openings between abdominal sternites 7 and 8; 7 / 8, single = single gland reservoir with opening between abdominal sternites VII and VIII. Mesocox [al]. Closure: Closed = lateral arms of meso- and metaventrites touching laterad of mesocoxa; Open = lateral arms not touching.

Figures 54 - 57. Dorsal habitus of representatives of Lagriini subtribes. 54 Lagria villosa (Fabricius, 1781), Lagriina 55 Statira pulchella Maeklin, 1864, Statirina 56 Phobelius lucifugus Fairmaire, 1889, Phobeliina 57 Rhosaces clavipes Champion, 1889, Phobeliina. Scale bars: 1 mm.

Figures 58 - 61. Prosterna of Lagriini. 58 Lagria villosa (Fabricius, 1781) 59 Statira gagatina Melsheimer, 1845 60 Phobelius sp. 61 Rhosaces sp.

Figures 62 - 67. Defensive gland reservoirs of Lagriinae. 62 Lagria villosa (Fabricius, 1781), Lagriini: Lagriina 63 Statira sp., Lagriini: Statirina 64 Phobelius sp., Lagriini: Phobeliina 65 Luprops sp., Lupropini 66 Aediotorix sp., Pycnocerini 67 Cardiothorax sp., Adeliini. Abbreviation: dgr = defensive gland reservoir.