Megistoleon ritsemae
Creators: name: Badano, Davide
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Neuroptera
Myrmeleontidae
Megistoleon
Megistoleon ritsemae

description: Megistoleon ritsemae (van der Weele, 1907)
(Figs. 1, 3, 5–8)
Diagnosis. Thorax mostly dark brown with two pale lateral stripes; forewings broad, hind wings narrower, almost falcate and a little longer than the first pair; forewing membrane mostly hyaline with dark brown infuscation at the apex and well defined markings just before the white pterostigma and in the radial area (Fig. 1).
Redescription. Size. Body length 41.4 mm (min-max 40.7–42.6); forewing length 47.2 mm (44.2–51.4), ratio width/length 0.028; hind wing length 49.0 mm (46.0–53.6), ratio width/length 0.13.
General coloring. Dorsally dark brown with yellowish stripes on the thorax and dark brown abdomen, ventral side very pale; brown markings of the wings restricted to the apical area.
Head. Vertex moderately raised, vertex and occiput pale brown with a central black stripe; frons and clypeus with a central black marking and with lateral light brown margins; labrum light brown; genae light brown; maxillary palpi light brown; labial palpi light brown with darker last palpomeres; antennae totally black, flagellomeres covered by short black setae.
Thorax. Pronotum dark brown with two lateral yellowish stripes and covered by sparse long and dark setae (Fig. 3); mesonotum and metanotum dark brown, the paler stripes of the pronotum continue along the sides of prescutum, mesoscutum, mesoscutellum, metascutum and metascutellum; yellowish brown areas are also present at wing insertion; pleural area marked by a longitudinal black stripe; ventral side very pale, almost whitish.
Legs. Coxae almost whitish; all pairs of legs with light brown femora and dorsally darker tibiae, tarsi brown; legs covered by long dark setae.
Wings. Wings of different shape: forewings broad with rounded apex, hind wings noticeably narrower, slightly falcate and a little longer than the first pair, venation mostly dark brown, longitudinal veins with alternating pale dashes; forewing with costal area divided in two rows of cells from Rs insertion and in three rows from middle length; pterostigma large, white and disposed after a contiguous dark marking; a small dark distinct spot is evident on the white coloured hypostigmatic cell; forewing membrane hyaline proximally with a stained apex; crossveins between M and CuA highlighted in brown; radial area with a dark brown elongate and curved marking; hind wing membrane basally hyaline and distally with a very large irregular brown marking; pterostigma very large, white, linked to a second white marking more apical in position; a small white spot is present near the posterior margin and bordered by the main brown area; apical wing margin of both wings infuscated (Fig. 1).
Abdomen. Abdominal tergites brown with paler, yellowish, posterior margins; sternites pale brown with darker lateral-posterior margins; pleural membrane light brown; abdomen with a thick covering of short black setae. Male terminalia as in Figs. 5–6. Ectoproct with the posterior portion darker than the anterior one; IX sternite completely pale. Male genitalia as in Figs. 7–8. Gonarcus arch-like; mediuncus flattened, only slightly prominent; parameres strongly connected to each other with an extended, flattened and sclerified apical part.
Specimens examined. 23 in alcohol: “Africa – Gabon: Makokou, Ipassa 520 m / 16.II-1.III.2012, C. Deiaco leg.”, D. Badano coll.; 13 pinned: “ 26.XII.1991 / Mt. Cameroon, Cameroon / leg. Rautenstrauch”, D. Badano coll.
Distribution. This rare antlion has been reported from Guinea, Congo, Gabon, Cameroon and Uganda (Prost 2010).
Ecology. The bio-ecology of this myrmeleontid is unknown, it appears to be a forest species. In Gabon (Makokou, Ipassa) it was collected at light during the first part of the night, from about 19:00 to 22:00, in a secondary growth forest (Deiaco pers. comm.).
description: Published as part of Badano, Davide, 2013, Description of Megistoleon thaumatopteryx sp. nov. with notes on the genus Megistoleon Navás (Neuroptera, Myrmeleontidae), pp. 194-200 in Zootaxa 3635 (2) on pages 195-198, DOI: 10.11646/zootaxa.3635.2.7, http://zenodo.org/record/223272