Disparomitus van der Weele, 1909

Michel, Bruno, 2019, Revision of the genus Disparomitus van der Weele, 1909 with descriptions of four new species (Neuroptera, Ascalaphidae), Zootaxa 4551 (1), pp. 1-39 : 3-4

publication ID	https://doi.org/ 10.11646/zootaxa.4551.1.1
publication LSID	lsid:zoobank.org:pub:F59DCDFC-6FAC-498E-A3F9-F176E0D499AB
DOI	https://doi.org/10.5281/zenodo.5934761
persistent identifier	https://treatment.plazi.org/id/B5738784-7A45-FFCD-FF57-FF0C0813FEF8
treatment provided by	Plazi
scientific name	Disparomitus van der Weele, 1909
status

Treatment

Genus Disparomitus van der Weele, 1909 View in CoL

Disparomitus van der Weele, 1909: 191 View in CoL .

Nanomitus Navás, 1912: 93 View in CoL n. syn.

Nagacta Navás, 1914a: 366 View in CoL n. syn.

Navás (1912) described the genus Nanomitus View in CoL on the basis of the length of the abdomen, which, in males, is shorter than the wings. Apart from this character, the original description of Navás corresponds to Disparomitus View in CoL , in particular the shape of the first abdominal tergite of the male. The parameres extend ventrally ( Figs 120–122 View FIGURES 114–132 ).

Navás (1914a) described the genus Nagacta on the basis of the following characters: hind spurs longer than metatarsus, pterostigma short and abdomen of male shorter than forewing with last segments not expanded laterally. I think that these charcters are not sufficiently discriminant to justify the creation of a new genus, especially since the last abdominal segments of the type specimen are expanded laterally contrary to what Navás states in the original description. Moreover, it is worth noting that Navás labeled the type specimen as Disparomitus leplaei ( Fig. 36 View FIGURE 35–36 ).

Type species: Suphalasca bacillus Gerstaecker, 1885 by original designation. Suphalasca is a subsequent spelling of Suhpalacsa Lefèbvre, 1842 (anagram of the genus name Ascalaphus ), used for the first time by McLachlan (1873).

Diagnostic characters. In most genera of Ascalaphidae , the first abdominal tergite is weakly sclerotized and divided along the dorsal midline into a pair of dorso-lateral plates, united by membranous tissue (Tjeder 1992). In Disparomitus , in the males and also to a lesser extent the females of some species, these plates are merged and generally developed into a dorsal projection notched in the middle with somewhat cone-like lateral elevations bearing erect stout setae. In his original description, van der Weele used the term “sattel-förmig” (saddle-shaped) to describe the shape of this projection observed from caudal view. Subsequently, this term was taken up by the various authors who described Disparomitus species. In the male, the lateral elevation of the first tergite and the anterior discal area of the second tergite bear a tuft of erect setae, often transformed into stout spines. These setae are naturally missing in females except in D. spatula n. sp. In some specimens kept in collection, these setae may have been damaged but the location of their insertion remains visible.

Males of three other genera of Ascalaphidae exhibit a dorsal projection on the first abdominal tergite. However, the shape of this projection is very variable and characteristic of each genus. In Dorsomitus Michel & Tjeder †, 2018 in Michel & Mansell, 2018, the first abdominal tergite is prolonged into a strong apically forked projection directed backwards with the apex of each prong covered by dense short black setae directed downwards ( Michel & Mansell 2018). In Fillus Navás, 1919 , the first abdominal tergite is elongated and folded horizontally on the second and third abdominal segments. In Pseudodisparomitus New, 1984 , abdominal tergite I bears a slightly domed prominence that is not bilobed dorsally. The parameres are hooked and slightly speculate and very different from those of Disparomitus . In Acmonotus MacLachlan, 1873 , it is the second abdominal segment, and not the first as mentioned in the original description by MacLachlan ( Kimmins 1929; New 1984; van der Weele 1909) that bears a conical projection with the apex curved backwards, bifurcate and covered with short stout bristles.

In the males, the abdomen is slender and longer than the forewings ( Fig. 134 View FIGURES 133–138 ), except in D. sellatus . The lateral surface of tergites I, II and anterior part of III is covered by small spine-like setae. Abdominal segments VI to VIII or VII and VIII are variably extended laterally. The abdominal sternites, in particular sternite III, have a conspicuous longitudinal black stripe, sometimes divided longitudinally by a line of white pruinosity. Under this pruinosity, the integument is black. Ectoprocts are sub-conical and slightly developed laterally ( Figs 32 View FIGURES 27–32 , 40 View FIGURES 37–40 , 46 View FIGURES 41–46 , 50 View FIGURES 47–52 , 75 View FIGURES 71–75 ). The sub-genital plate is convex and terminates in a blunt tip ( Fig. 75 View FIGURES 71–75 ).

The gonarcus-parameres complex is well developed ( Figs 81, 82 View FIGURES 78–83 , 96–132 View FIGURES 96–113 View FIGURES 114–132 ). Its general shape is constant in all the species with the exception of D. lineatus n. sp. whose gonarcus, in lateral view, is clearly narrowed anteriorly and has a triangular shape. The parameres have a granular surface and their internal edge is denticulate. They extend ventrally as a carina whose length is close to that of the paramere. This carina may be laterally reflected and visible from above.

Females are the same colour as the males or lighter in colour; the abdomen is shorter than the wings. The first abdominal tergite is not expanded dorsally except in D. spatula n. sp. ( Fig. 69, 70 View FIGURES 64–70 ). Ectoprocts are scale-like and rounded apically. The linguella is not divided. There is no interdens ( Figs 1, 2 View FIGURES 1–3 ).

Disparomitus exhibits morphological features also manifested in other genera. The labial palp is three segmented and the apical segment bears a small median sensory pit ( Fig. 3 View FIGURES 1–3 ). The antennae do not reach the pterostigma. Forewings are longer than hind wings. The wings are generally hyaline but can be slightly suffused with brown, particularly between the subcostal and radial veins.