Psalidognathus mygaloides Thomson, 1859

Santos-Silva, Antonio & Spooner, Amoret, 2021, On some species of Psalidognathus Gray, especially those of the group “ superbus ” (Coleoptera, Cerambycidae, Prioninae), Zootaxa 5023 (3), pp. 389-404 : 390-392

On Psalidognathus mygaloides Thomson, 1859

( Figs 1–4)

Psalidognathus Mygaloides Thomson, 1859b: 41 .

Thomson (1859b) was the first to divide Psalidognathus into two groups of species in his key (translated): “Antennae submoniliform or not spinose; general color dark”—leading to P. erythrocerus Reiche, 1840 , and P. modestus Fries, 1834 ; “Antennae subpectinate or spinose”—leading to P. mygaloides Thomson, 1859 , P. incas Thomson, 1859 , P. sallei Thomson, 1859 , and P. friendii Gray, 1831 . Curiously, Thomson (1859b) did not comment on P. superbus Fries, 1834 .

Later, Thomson (1877a) reported on P. modestus (translated): “As P. MODESTUS was figured by M. Fries as having the forehead armed with two horns on the disc, it is perhaps identical with P. MYGALOIDES Thomson , cited below. In the event that the previous fact is certified, we propose to establish a crossover of names between these two species, that is to say, to name P. MODESTUS Fries in Thomson Monog. by the name of P. MYGALOIDES Thomson , and P. MYGALOIDES Thomson Monog. by the name of P. MODESTUS Fries .” Thomson (1877a) excluded the female included by him as P. mygaloides , and transferred it to P. sallei . Consequently, P. mygaloides sensu Thomson (1859b) became represented by only one male specimen.

We note the following regarding P. modestus and P. mygaloides :

1. It is difficult to be sure about the true identity of the male described by Thomson (1859b) as P. mygaloides ( Figs 1–4), and currently considered a synonym of P. modestus , since according to him on this specimen (translated): “Antennae… spinose at extreme apex of nearly all antennomeres.” Psalidognathus modestus has the apex of the antennomeres, at most, slightly projected. Furthermore, those two species were included in different points of Thomson’s (1859b) key, precisely based on the shape of the apex of the antennomeres;

2. Thomson (1877a) did not formalize the exchange of the names between P. modestus and P. mygaloides : he only suggested that this could be possible. However, if the change was accepted, P. mygaloides Thomson, 1877 would become a homonym of P. mygaloides Thomson, 1859 ;

3. Lameere (1885) considered P. modestus sensu Thomson (1859) as P. thomsoni (a nomen novum) ( Figs 5–8);

4. P. mygaloides sensu Thomson (1859) ( Figs. 1–4) is currently considered a junior synonym of P. modestus Fries ;

5. Quentin & Villiers (1983) summed up the situation as follows: “a. mygaloides mâle Thomson, 1859. Nous désignons comme lectotype un mâle de 60 mm de longueur portant les étiquettes suivantes: «Th., Type», «Ex Musaeo James Thomson», «Mygaloïdes, Type, Th., Ar. n., 41, Col a.», «Muséum Paris, Coll. J. Thomson, 1952».” = P. modestus ; and “ P. thomsoni Lameere, 1885 / = P. modestus Thomson, 1859 / = P. mygaloides Thomson, 1877 nec Thomson, 1859 (mâle).” As Thomson (1859b) had only a male of P. mygaloides , it is not possible to conclude that Quentin & Villiers (1983) had chosen a male specimen with antennae with a different shape.

6. The photographs of the lectotype of P. mygaloides Thomson, 1859 ( Figs 1–4), sent by Gérard L. Tavakilian (MNHN), match the true P. modestus . However, they do not agree with the original description (Thomson 1859) because the antennomeres are not spinose at the apex. Consequently, the true identity of this species remains a mystery.