Merizomma codonopsivora Vilkamaa & Menzel 2019
Creators: name: Vilkamaa, Pekka
name: Menzel, Frank
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Sciaridae
Merizomma
Merizomma codonopsivora

description: Merizomma codonopsivora (Sasakawa, 1997) stat. et comb. n.
Literature. Lycoriella (Chorizomma) codonopsivora Sasakawa—Sasakawa (1997): 171, figs 1–3. Lycoriella (Merizomma) codonopsivora Sasakawa—Sasakawa (2003): 119, 128. Lycoriella codonopsivora Sasakawa—Sa-sakawa (2008): 128; Eiseman et al. (2016): 527.
Discussion. Sasakawa (1997: 171) described the distinctive Lycoriella codonopsivora Sasakawa, 1997 from Hokkaido (Japan) whose larvae feed on deodeok leaves (Codonopsis lanceolata, Campanulaceae). For this species, he erected the monotypic subgenus Chorizomma of Lycoriella (Sasakawa 1997: 174 [preocc., not Chorizomma Simon, 1872; Araneae, Dictynidae] and renamed the subgenus later as Merizomma (Sasakawa 2003: 119, 128). The subgenus and the type species are not included in the monograph of the Palaearctic Sciaridae (Menzel & Mohrig 2000). Therefore, these taxa are discussed here in detail on the basis of the original descriptions by Sasakawa (1997) and included in the identification key and in the checklist.
Lycoriella codonopsivora Sasakawa, 1997 has characters which are not present in this combination in any other genus and which distinctly differ from those given to Lycoriella s. l. by Menzel & Mohrig (2000: 377):
Eye bridge not united at middle, without ommatidia; maxillary palpus 2-segmented, without pit of sensilla on 1 st segment; scutellum without long lateral setae, only with two unregular rows of short setae; R 1 longer than R, ending beyond the base of M-fork; fore tibia with small, bow-like bordered tibial organ; tarsal claws untoothed; hypopygium with wide gonocoxa; gonocoxae united in v-form and with short setae, intergonocoxal area not modified, gonostylus elongate-triangular and with apical megaseta, without apical tooth; medial side of gonostylus without megasetae and at apical half strongly impressed; basal part [at 1/5 of the medial side of gonostylus] with long, upcurved seta on long basal body; tegmen roundish, without apical or lateral modifications.
On the basis of the above characters, L. codonopsivora Sasakawa must be excluded from the Lycoriella group. With its short gonocoxa, lacking intergonocoxal lobe and apical megaseta, the species resembles some species of the K. nepalensis group of Keilbachia Mohrig, 1987 [compare here Menzel & Martens (1995: 107), Menzel & Mohrig (2000: 348), Vilkamaa et al. (2006: 40) and Vilkamaa et al. (2009: 3)]. However, a strongly reduced eye bridge, a 2-segmented palpus, an unbordered patch of sensilla on 1 st segment of palpus, a long R 1 and the lack of a spiral-formed megaseta on the medial side of gonostylus differ from the characters of Keilbachia. These characters are typical for the M. hippai group of the genus Mohrigia Menzel, 1995. Speaking against the combination of L. codonopsivora Sasakawa with Mohrigia are the Keilbachia -like form of the gonostylus, the missing long medial setae on the apical half of the gonostylus, the missing intergonocoxal lobe of hypopygium and the much smaller, weakly setose fore tibial organ [compare here Menzel & Martens (1995: 102), Menzel & Mohrig (2000: 415) and Rudzinski (2006: 450)]. Furthermore, neither Keilbachia nor Mohrigia have the lateral setae of scutellum reduced [both have two long and strong setae] nor an unmodified tegmen [the tegmen of Mohrigia has a straight, strongly sclerotized dorsomedial structure; the tegmen of Keilbachia is sclerotized laterally and often with a narrow apical process]. On the above grounds, Merizomma Sasakawa, 2003 stat. n. with the type species Merizomma codonopsivora (Sasakawa, 1997) comb. n. is raised to generic rank and excluded from the Lycoriella group sensu Menzel & Mohrig (2000).
description: Published as part of Vilkamaa, Pekka & Menzel, Frank, 2019, Re-classification of Lycoriella Frey sensu lato (Diptera, Sciaridae), with description of Trichocoelina gen. n. and twenty new species, pp. 1-67 in Zootaxa 4665 (1) on page 8, DOI: 10.11646/zootaxa.4665.1.1, http://zenodo.org/record/4000553