Securiops, : Kluge, 2020

Kluge, Nikita J., 2023, Redescription of the subgenus Securiops Jacobus, McCafferty & Gattolliat 2006 (Ephemeroptera, Baetidae, Procloeon Bengtsson 1915), Zootaxa 5343 (3), pp. 243-272 : 251-252

Status of Securiops .

Kaltenbach et al. (2023) treated Securiops as a genus but not as a subgenus, reporting the following its characters as generic ones: ́(1) labium with strongly reduced glossae, enlarged paraglossae, and very broad, hatchet-like palps; (2) tergalii I–IV with two lamellae; (3) legs elongate, with relatively few short setae on dorsal and ventral margins; (4) claws very elongate, without denticles; and (5) lateral margins of posterior abdominal segments with sharp spines». Actually, only the first of these characters constitutes autapomorphy of the subgenus Securiops , while the characters (2)–(5) are diagnostic for the taxon Cloeon /fg1, to which the subgenus Securiops belongs. The regular lateral row of greatly enlarged spines on distal part of cercus ( Figs 71–72 , 105 , 124–125 ) is the most important diagnostic character of Procloeon s. l., to which the subgenus Securiops belongs.

Distribution. Paleotropical (Afrotropical and Oriental Regions).

Species composition. Afrotropical species: Procloeon (Securiops) falcatum ( Crass 1947) comb. n.; P. (S.) macafertiorum (Lugo-Ortiz in Lugo-Ortiz & McCafferty 1996); P. (S.) mandrare ( Jacobus, McCafferty & Gattolliat 2006) comb. n.; P. (S.) megapalpus ( Jacobus, McCafferty & Gattolliat 2006) comb. n.; P. (S.) mutadens ( Jacobus, McCafferty & Gattolliat 2006) comb. n.. Oriental species: Procloeon (Securiops) primasia ( Kaltenbach et al. 2023) comb. n.

Key to larvae (the number in parentheses refers to the antithesis)

1(4) Hind protoptera present ( Figs 29 , 67 ) (can be poorly visible, since cuticle of hind protopteron is colorless)............... 2

2(3) Abdominal terga IV–X with numerous scales ( Figs 55–56 ); terga IV and VII without medial longitudinal stripe ( Fig. 26 )........................................................................................... P. (S.) falcatum

3(2) All abdominal terga without scales, with numerous denticles ( Fig. 74 ); terga IV–V and VII–IX with contrasting medial longitudinal stripe on light background ( Figs 66, 69 )........................................ P. (S.) macafertiorum

4(1) Hind protoptera absent ( Fig. 108, 111 ) or represented by short vestiges ( Fig. 102 ).

5(6) Spines on lateral side of cercus sharply differentiated: in proximal portion of cercus all spines stout, conic and not longer than next cercomere; in distal portion of cercus all spines delicate, widened from base, as long as 2–3 next cercomeres ( Figs 124–125 ). Tergalii with apex stretched and pointed, resembling linden leaf ( Figs 18–24 )................. P. (S.) primasia

6(5) Spines on lateral side of cercus gradually change from shorter in proximal part of cercus to longer in its distal part ( Fig. 105 ). Tergalii with apex rounded ( Gillies 1988: figs 14–19)..................................................................................................... P. (S.) mutadens ; possibly, also (S.) mandrare and P. (S.) megapalpus .

Figures

FIGURES 70–76. Procloeon (Securiops) macafertiorum. 70, subimaginal exuviae: apex of tibia and base of tarsus of fore leg of male; 71–76, larval exuviae: 71, caudalii; 72, fragment of cercus; 73, fragment of fore tarsus; 74, abdominal tergum IV; 75, abdominal sternum V; 76, abdominal tergum X, paraproct and margin of tergum IX.

FIGURES 98–105. Procloeon (Securiops) mutadens. 98–99, left and right mandibles; 100, labrum; 101, maxilla; 102, larval cuticle of metanotum with vestige of hind protopteron; 103, abdominal tergum V; 104, abdominal sternum V; 105, caudalii. Abbreviation: sc, scales and scale sockets.

FIGURES 120–125. Procloeon (Securiops) primasia, larval exuviae. 120, base of tibia of fore leg, with focus on dorsal side; 121, the same with focus on ventral side; 122, abdominal tergum V; 123, abdominal sternum VIII; 124, cercus and paracercus; 125, portion of cercus.

FIGURES 25–30. Procloeon (Securiops) falcatum. 25–28, larval exuviae (with same magnification): 25, abdominal sterna; 26, abdominal terga; 27, half of pronotum and mesonotum; 28, fore leg; 29, exuviae of metanotum with hind protoptera, left metapleuron and 1st abdominal tergum, enlarged; 30, fore protopteron, to show correspondence between cuticular coloration and veins visible inside.

FIGURES 66–69. Larvae of Procloeon (Securiops) macafertiorum. 66–68, larval exuviae (with same magnification): 66, abdominal terga and sterna; 67, thoracic sterna, pleura, halves of metanotum with hind protoptera and right legs (arrows show hind protoptera); 68, half of pronotum and mesonotum; 69, last instar male larva.

FIGURES 53–58. Procloeon (Securiops) falcatum, exuviae of larval abdomen. 53–56, terga II, III, IV and IX; 57, sternum IV; 58, constant bifurcate seta on sublateral part of sternum VIII.

FIGURES 106–115. Procloeon (Securiops) primasia, larval exuviae. 106–108, dark individual (female); 109–115, light individual (male); 106, 115, abdominal terga and sterna; 107, 110, half of pronotum and mesonotum; 108, 111, left thoracic pleura and half of metanotum; 109, part of head; 112–114, fore, middle and hind legs.

FIGURES 1–24. Right tergalii of Securiops with dorsal lamella turned out. 1–7, Procloeon (Securiops) falcatum, tergalii I–VII; 8–17, two individuals of P. (S.) macafertiorum: 8–11, tergalii I–II and V–VII; 12–16, tergalii I–V; 17, the same individual, margins of abdominal segments VII–IX with tergalius VII in natural position; 18–24, P. (S.) primasia, tergalii I–VII.