Amphientomum Pictet, 1854

Boudinot, Brendon E., Bock, Bernhard L., Weingardt, Michael, Troeger, Daniel, Batelka, Jan, LI, Di, Richter, Adrian, Pohl, Hans, Moosdorf, Olivia T. D., Jandausch, Kenny, Hammel, Joerg U. & Beutel, Rolf G., 2024, Et latet et lucet: Discoveries from the Phyletisches Museum amber and copal collection in Jena, Germany, Deutsche Entomologische Zeitschrift 71 (1), pp. 111-176 : 111

Genus Amphientomum Pictet, 1854

Amphicetomum = Amphicetomum Hagen, 1859.

Palaeoseopis = Palaeoseopis Enderlein, 1925 syn. nov. (Type species: † Am. colpolepis Enderlein, 1905 by original designation.).

Type species.

† Am. (Amphientomum) paradoxum Pictet, 1854.

Remarks.

Pictet (1854) first described the genus from Baltic amber. Enderlein (1905, 1911) defined several character states that define the genus Amphientomum . These include a large body size, a relatively small ocellar area where the distance between the ocelli is short, a lack of spur sensilla on the maxillary palpomeres, an elongated and narrow fourth maxillary palpomere, labial palps with two articles, antennal flagellum with secondary annulation, presence of a complete R1 vein in the hindwing, and perhaps more surprisingly the occurrence of only 13 flagellomeres ( Enderlein 1911, p. 333). The number of antennomeres might be an oversight by Enderlein (1911), as Hagen (1882) had already described the number of articles (15) correctly. In his revision of Pearman’s (1936) phylogenetic system of Psocoptera , Roesler (1944) provided morphological characters to define previously established groupings including the Amphientomidae . In so doing, Roesler designated the previously established genus Amphientomum Palaeoseopsis Enderlein, 1925 as a subgenus of Amphientomum . As such, Am. (Palaeoseopsis) is supposed to differ from Am. (Amphientomum) by the open basiradial cell, the lack of the basal section of Rs in the hindwing, and the emarginate scale tips ( Enderlein 1925; Roesler 1944). Badonnel (1955) went a step further and proposed that the subgenus Palaeoseopsis can be removed entirely but did not follow through on this action. It should be noted that an open basiradial cell in the hindwing occurs in all species of the genus that are outside the subgenus Am. (Amphientomum) , as in most species only a short spur vein of the basal section of Rs is present or the basal section of Rs is entirely missing. Phylogenetic studies on this genus are lacking and the monophyly of the subgenera Am. (Palaeoseopsis) and Am. (Amphientomum) is therefore questionable, as they are neither supported by morphological apomorphies, nor by molecular data. We therefore formalize the synonymy of Amphientomum and Palaeoseopsis j. syn., syn. nov. The diagnostic characters of the genus Amphientomum are as follows after the identification key by Taylor (2013): presence of wings, the vein M in the hindwing simple, presence of three ocelli, the lateral ocelli closer to each other than to compound eyes, the vein R1 reaching the wing margin in the hindwing, and the distal section of the vein Sc in the forewing present. See also the Remarks section for † Am. knorrei sp. nov.

Note.

The term sulcus is used here when an external line or furrow corresponds with an internal ridge, i.e., a strengthening ridge ( Girón et al. 2023). If no internal ridge is present but a narrow zone of weakness, we use the term suture (e.g., frontal suture). The typical coronal suture (part of the ecdysial suture) of other insects corresponds with an internal ridge in adult psocids and is therefore here classified as a coronal sulcus. The frontal sutures (part of ecdysial suture) are similarly developed as in other insects, without an internal strengthening ridge. The term epistomal sulcus is used as synonym of the frontoclypeal line.