Amphineurus Skuse, 1890

Santos, Daubian, Santos, Rodrigo dos Reis & Ribeiro, Guilherme Cunha, 2022, Systematics of Amphineurus (Rhamphoneurus Alexander) (Diptera: Tipuloidea: Limoniidae), Arthropod Systematics & amp; Phylogeny 80, pp. 439-494 : 439

publication ID	https://dx.doi.org/10.3897/asp.80.e83035
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scientific name	Amphineurus Skuse, 1890
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3.1. Genus Amphineurus Skuse, 1890 View in CoL

Amphineurus Skuse, 1890: 800 (as a subgenus of Rhypholophus ). Type-species: Amphineurus (A.) umbraticus Skuse, 1890 (as Rhypholophus ).

Diagnosis.

Amphineurus can be diagnosed by the following combination of characters: gonocoxite bifid; wing with R2+3+4 aligned with R2+3. When there is an element R4+5 (and therefore, no R2+3), members of the genus are distinguished from other Chioneinae by the closed discal cell.

Remarks.

There is great diversity in the male terminalia of Amphineurus (Figs 1 View Figure 1 , 2 View Figure 2 ). There are many variations from the simplified pattern of A. (A.) patya Theischinger (Fig. 1A View Figure 1 ) to the asymmetric disposition of A. (Nesormosia) (Fig. 2D View Figure 2 ). Therefore, defining a broad diagnosis for Amphineurus is not so easy. Skuse (1890) defined Amphineurus as a subgenus of Rhypholophus . Skuse’s definition fits better to the current subgenus A. (Amphineurus) but does not portray the reality of other species of Amphineurus . His diagnosis included the absence of the discal cell, the radial sector with four branches, "second longitudinal vein angulated", and hind femora one third longer than the intermediate pair. These features are non-exclusive or variable in the genus.

Alexander (1920) allocated Amphineurus as a subgenus of Ormosia after highlighting the abundant and conspicuous wing macrotrichia (Fig. 5B View Figure 5. A ). Edwards (1923) redefined the genus to support two New Zealand species. Edwards’ diagnosis includes the short mid-leg, short and hairy wing, and radius four-branched. Nevertheless, these features occur in other Chioneinae . Edwards (1923) also referred to the fact that the medial vein forks in M3+4 and M1+2 and that the anal vein is sinuous. These features are plastic in the genus. Alexander (1929a) used the definition of Edwards (1923) and emphasized the characteristic "abundant trichiation" of the genus. However, in the same article, Alexander (1929a) described the genus Maietta , which has more wing vestiture than Amphineurus . Some species of the Neotropical subgenus A. (Rhamphoneurus) have less macrotrichia than other subgenera. No more inclusive diagnosis was proposed and recent revisions (e.g., Theischinger 1994, 1996) redefined only the diagnosis of the subgenus A. (Amphineurus) .

Amphineurus has an 180 º rotation of male terminalia (in the words of Edwards: "undergone permanent torsion"). Edwards (1923) also shows that Amphineurus has a long, finger-like gonocoxite process (Fig. 1A View Figure 1 ). This is evidence of the bifid gonocoxite, a condition present (Fig. 29G View Figure 29 ) in some Chioneinae with inverted male terminalia. This gonocoxal process forms a protective hood ( Kramer 2020) for the appendices of the inverted terminalia.

The Chioneinae genera with inverted terminalia bear great diversity and frequently they have hairy wings similar to Amphineurus . The great amount of wing vestiture resembles Maietta Alexander. The wings of some A. (Amphineurus) (Fig. 32 View Figure 32 : Node 18) have a distinctive radial sector such as seen in Molophilus Curtis. Some A. (Amphineurus) (Fig. 32 View Figure 32 : Node 23) resembles Hoplolabis ( Parilisia Savchenko). The trifid claspers of A. (Rhamphoneurus) are observed in genera such as Hoplolabis Osten Sacken and Cheilotrichia Rossi. Despite that, in the group of genera with a bifid gonocoxite and inverted terminalia, vein R2+3 is normally aligned with R2+3+4. The exception is a clade of A. (Amphineurus) (Fig. 32 View Figure 32 : Node 18) that shows resemblances in the radial sector with Molophilus (where R2+3+4 is lacking), but the former has a closed discal cell among other wing features which places it within Amphineurus .