Psychomyiinae Walker 1852
Creators: name: Tachet, Henri
name: Coppa, Gennaro
name: Forcellini, Maxence
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Trichoptera
Psychomyiidae

description: Comparative morphology of larvae of Psychomyiinae
The characters presented above concern only the three described species. To discover whether these characters have more general taxonomic value, we examined other species belonging to these three genera. We have considered either descriptions found in the literature or, preferably, whenever possible, larvae kindly lent or donated by colleagues. We have considered only the most relevant characters. The characters concerning the size at last instar, the mandibles and the thoracic legs have been were set aside, because, for these three characters, the descriptions were either absent or too basic to be useful.
Metalype (Figs 2, 5, 8, 11, 15, 18, 22, 26–29, 32) — Torii (2011a) described the larva of Metalype uncatissima. It shares with M. fragilis, the following characters: the anal claw has teeth on the ventral margin (Qiu et al 2017); the pronotum has a black, diagonal thickening on the posterolateral margin; and the anterior margin of the head is straight, without the notches seen in some species of Psychomyia. The submental sclerites and the ventral apotome of the head are very similar to those of M. fragilis; however, there are 7 to 8 well-developed teeth on the ventral margin of the anal claw in M. uncatissima, instead of two or three in M. fragilis. The colour pattern is uniform in M. fragilis, but there are coloured stripes in M. uncatissima. As in M. fragilis and M. klapaleki, the two posterior prosternites of M. uncatissima are dark).
Qiu et al. (2017) have examined the adults of eleven species of Metalype and three species of Psychomyia, considering the male genitalia and the apicomesal spurs of the hind tibiae. Concerning the genitalia, three characters are especially relevant: The male superior appendages each have a subapicomesal tooth in Metalype, but are without a tooth in Psychomyia; the male harpagones are expanded dorsally in Metalype, not in Psychomyia; male tergites IX + X are fused with the superior appendage in Psychomyia, but not in Metalype. Concerning the mesal spurs and the lateral spur of the hind tibiae: the mesal spur is shorter than the lateral spur in Metalype, It is the opposite for Psychomyia.
Torii & Nakamura (2016, Fig 3) indicate, for larvae of Metalype, the presence of only one suture between the protrochantin and the episternum, but, in fact, there are two sutures (see Fig. 26) as for Psychomyia and Paduniella, but these two sutures are often hard to see because the cuticle is thick in Metalype (see Fig.18).
Psychomyi a (Figs 1, 4, 7, 10, 14, 17, 23, 31, 37–40)—Although about 150 Psychomyia species have been described, the larvae of only three species have been described in detail: Psy. pusilla by Lepneva (1964) in European Russia (also Waringer & Graf 2011), Psy. lumina by Wiggins (1996) in North America, and Psy. ctenophora McLachlan 1884, by Vieira-Lanero (2000) in Spain. Larvae of Psychomyia flavida and P. nomada have been described very succinctly (Flint 1964). In P. pusilla, the head is almost square with almost parallel lateral margins. The anterior margin of the frontoclypeal apotome bears two blackish processes lateral to a shallow median indentation. Ventrally, the submental sclerites are dark, large, thick, and heavily ornamented, with their anterior margins on a straight line perpendicular to the median line, the posterior lateral angle is obtuse; on each submental sclerite, along the median line, there is a succession of irregular transversal rolls. The ventral apotome is a small equilateral triangle. These characters occur in a Spanish P. pusilla, but the ventral apotome has two short lateral points (Vieira-Lanero 2000) indicating an intraspecific variability. In P. ctenophora (Vieira-Lanero 2000), the submental sclerites are thin; their anterior margins form a backwards-obtuse angle. The ventral apotome has two massive short lateral points (Fig.39). In P. flavida, the head is almost square; the anterior margin of the frontoclypeal apotome has two bulges separated by a shallow depression. The submental sclerites are thin with a succession of transverse rolls; their anterior margins are on a straight line perpendicular to the median line. The ventral apotome is a small equilateral triangle (Fig.38). In an undetermined Korean species of Psychomyia (http:// blog.naver.com/nstdaily), the submental sclerites are thin with a shape similar to that of P. flavida. The ventral apotome has a pair of long, transverse, massive lateral points. The two rounded bulges of the anterior margin of the head each forms a single mass situated near the joint socket receiving the ventral condyle of the mandible (Fig.40). In all the larvae of Psychomyia described until now, the submental sclerites are similarly shaped. They are never transversally elongated, as they are in Paduniella and Metalype. The ventral apotome shows a certain variability, but even when there are two transverse massive lateral points (undetermined Korean species), the shape of the ventral apotome is different from that of Metalype or Paduniella. Furthermore, Psychomyia lumina and P. flavida correspond to two levels of specialization according to Schmid (1997), low level (Psy. arefinae Group) for P. lumina and high level for P. flavida (Psy. flavida Group), but the morphology of the submental sclerite and the ventral apotome of their larvae is very similar in these two species (Figs 37, 38). There is clearly a gap between the most primitive (or the less specialized) Psy. arefinae Group and the M. mahayinna Group sensu Schmid (1997) that corresponds to the genus Metalype.
Paduniella (Figs 3, 6, 9, 13, 16, 19, 21, 25, 30, 33, 42–44, 45–47)—Besides P. vandeli, we were able to examine one unidentified species (either P. capensis or P. ankya) from South Africa (thanks to the kindness of Ferdy de Moor). For the larva of P. nearctica we have the descriptions of Mathis & Bowles (1994), Wiggins (1996), and Li & Morse (1997b). The small size of of these larvae is a character of Paduniella (compare Figs 1–3). During the sorting of a sample of benthos, the Paduniella larvae are often not recognized and hence discarded because they are taken to be as unidentifiable young larvae (fourth or third instars) of other Psychomyiinae. Unlike the other two genera, the diagonal black thickening on each lateral posterior angle of the pronotum is straight, thus its anterior extremity is visible dorsally (de Moor & Scott 2003; Wiggins 1996), whereas in Psychomyia and Metalype the distal part of the diagonal black thickening is curved and invisible in dorsal view. In Pad. vandeli, in the South African Paduniella and in P. nearctica, the anterior margin of the frontoclypeal apotome is almost straight. The arrangement and the shape of the submental sclerites are very similar to those of Metalype (Figs 11, 13). The number of the teeth on the ventral margin of an anal claw of the last instar larvae is 4 for Pad. nearctica (Mathis & Bowles 1994), 7 to 8 for the South African species and Pad. vandeli. Behind the posterior bases of the coxae of the prothoracic legs, there are no dark posterior prosternites as in Metalype and Psychomyia, but only a colourless bell-shaped thickening in the middle of the prosternum (Figs 42–44). Exceptionally, we have precise descriptions of the mandibles for these three species of Paduniella belonging to three different Regions (Figs 45– 47). The right mandible “has a prominent mesal notch” in P. nearctica (Nearctic) (Wiggins 1996), a less-prominent mesal notch in P. (ankya or capensis) (Afrotropical), and no mesal notch in P. vandeli (West Palearctic). Thus, the presence or absence or prominence of this “mesal notch” on the right mandible is not a common character of the genus Paduniella.
description: Published as part of Tachet, Henri, Coppa, Gennaro & Forcellini, Maxence, 2018, A comparative description of the larvae of Psychomyia pusilla (Fabricius 1781), Metalype fragilis (Pictet 1834), and Paduniella vandeli Décamps 1965 (Trichoptera: Psychomyiidae) and comments on the larvae of other species belonging to these three genera, pp. 91-112 in Zootaxa 4402 (1) on pages 103-105, DOI: 10.11646/zootaxa.4402.1.4, http://zenodo.org/record/1208486