Megagonoleon Machado, 2020

Machado, Renato Jose Pires & Oswald, John David, 2020, Morphological phylogeny and taxonomic revision of the former antlion subtribe Periclystina (Neuroptera: Myrmeleontidae: Dendroleontinae), Zootaxa 4796 (1), pp. 1-322 : 184-185

Megagonoleon Machado , new genus

http://zoobank.org/NomenclaturalActs/ 4A12B41B-2423-442F-BD9F-2F007074E5BC

Type species. Gymnocnemia pentagramma Gerstaecker, 1885 , by present designation. Nomenclatural gender: masculine.

Diagnosis. Forewing, posterior Banksian line absent; female lateral gonapophysis about same size as ectoproct; female posterior gonapophysis, absent or narrow, without cavisetae; male gonarcus with posterior margin narrower than anterior (lateral view).

Description. Head: Vertex raised. Ocular setae absent (very small in some species). Antennae clubbed and elongate; flagellomeres almost as long as wide at base, apical ones wider than long. Palpimacula opening ovalshaped, located medially. Thorax: Pronotum usually almost as long as wide (except cahillensis species group). Miller’s organ present. Wings: hyaline with brown marks, and generally broad. Anterior Banksian line present in both wings, posterior absent. Hind wing with one presectoral crossvein. Male pilula axillaris present. Legs: Profemur longer than procoxa. Sense hair absent or slightly longer than profemur width. Male Terminalia: Ectoproct posterior margin rounded; gonarcus posterior margin thinner than anterior (lateral view). Female Terminalia: Ectoproct posterior margin rounded and usually set with cavisetae; lateral gonapophyses about same size as ectoproct and set with cavisetae; posterior gonapophyses absent or thin, without cavisetae; anterior gonapophyses usually absent.

Distribution ( Figs. 92 , 101 , 111 , 120 , 129 , 138 ). Australia: NSW, NT, QLD, SA, VIC, WA. Widespread across mainland Australia.

Included species (22 spp.; monophyletic; 3 species groups). cahillensis group (3 spp.; monophyletic): M. cahillensis , M. lesouefi , M. newi sp. nov., pentagrammus group (11 spp.; monophyletic): M. breviplectron sp. nov., M. cardaleae , M. longidigitus sp. nov., M. lulinguensis , M. nigrescens , M. oombulgurriensis sp. nov., M. pentagrammus , M. rebellis sp. nov., M. sarahae , M. tillyardi , M. tindalei , stigmatus group (8 spp.; monophyletic): M. annulatus , M. banksi , M. drysdalensis , M. pingrupensis , M. punctatus sp. nov., M. radialis , M. roseipennis , M. stigmatus .

Biology. Unknown.

Etymology. Mega - (from Greek megas, large or great) + - gono - (from Greek gonos, seed or offspring) + - leon (from Greek leon, lion; a traditional antlion genus-group name ending), in reference to the large female lateral gonapophyses found in most of its included species.

Comments. Megagonoleon gen. nov. is created here to accommodate a number of species that were previously placed in Austrogymnocnemia and Glenoleon , together with new species belonging to the greater Megagonoleon clade. These species are united primarily by the shape of the female terminalia (lateral gonapophysis large and bearing many cavisetae, posterior gonapophysis absent or reduced and without cavisetae). These characteristics separate the Megagonoleon clade from the remaining genera of the Periclystus genus group and are demonstrated here to provide a more robust basis for phylogenetic/taxonomic grouping than the presence or absence of tibial spurs, which has been the principal character used to group or separate these species in the past. The 22 species included in Megagonoleon can be separated into three species groups: cahillensis, pentagrammus and stigmatus .

The cahillensis species group contains three species, two previously placed in Glenoleon ( M. cahillensis and M. lesouefi ) and one new species ( M. newi sp. nov.). This small group was recovered as sister to the two other groups, and its basal position can apparently be attributed to the presence of several characters that are more closely associated with Glenoleon , Periclystus and Riekoleon (e.g., legs and pronotum elongate) than they are with other Megagonoleon species. However, the overall shape of the female terminalia justify their placement phylogenetically and taxonomically within Megagonoleon .

The stigmatus species group contains eight species, seven previously placed in Glenoleon ( M. annulatus , M. banksi , M. drysdalensis , M. pingrupensis , M. radialis , M. roseipennis , and M. stigmatus ) and one new species ( M. punctatus sp. nov.). The members of this group are united by similarities in the overall shape of the male terminalia, the presence of a small femoral sense hair, the tibial spurs reaching T1 apex (except M. drysdalensis ) and the fairly broad forewing. This group includes all of the large and orangish species previously placed in Glenoleon , having been placed there on the basis of the presence of tibial spurs.

The pentagrammus species group contains 11 species, one previously placed in Glenoleon ( M. tillyardi ), four new species ( M. breviplectron sp. nov., M. longidigitus sp. nov., M. oombulgurriensis sp. nov. and M. rebellis sp. nov.), and six species previously placed in Austrogymnocnemia ( M. cardaleae , M. lulinguensis , M. nigrescens , M. pentagrammus , M. sarahae and M. tindalei ). Within this group, the six species formerly placed in Austrogymnocnemia and M. oombulgurriensis are closely related and can be grouped based on the absence of tibial spurs and the general configuration of the male terminalia. The remaining four species were recovered as basal to the other species and are quite distinctive, particularly M. tillyardi and M. longidigitus , in which the lateral gonapophysis is reduced and a long membranous digitiform process is present. Nevertheless, both morphological ( Fig. 4 ) and molecular ( Machado et al. 2019) phylogenies justify the placement of these species in the pentagrammus species group.

Figures

FIGURE 4. Strict consensus tree of morphology-based parsimony analysis of species belonging to the former subtribe Periclystina (ingroup, names in black), and outgroups (names in red). Former Glenoleon species are shown on blue branches, former Austrogymnocnemia species on green branches. Numbers above branches are Bremer support values; numbers below branches are bootstrap values (shown where>50%).

FIGURE 92. Distribution of Megagonoleon species (part).

FIGURE 101. Distribution of Megagonoleon species (part).

FIGURE 111. Megagonoleon newi sp. nov.: a) head, anterior; b) head and thorax, dorsal; c) male terminalia, posterolateral; d) wings, dorsal.

FIGURE 120. Megagonoleon pingrupensis: a) head, anterior; b) head and thorax, dorsal; c) wings, dorsal.

FIGURE 129. Megagonoleon roseipennis: a) head, anterior; b) head and thorax, dorsal; c) wings, dorsal.

FIGURE 138. Megagonoleon tindalei: a) head, anterior; b) head and thorax, dorsal; c) wings, dorsal.