(Figs. 1-3 ab, 4a, 5a, 6-7, 8-11, 16e)
Material examined. Holotype: MONTENEGRO, Podgorica municipality, Gornji Mileš, Rogamsko brdo, Cijevna River, N42°23’59.7”, E19°18’42.6”, 65 m a.s.l., 25.05.2009, 1♀ +O (Figs. 8-9, 11, 16e), KT-MG-UL, MM: 2009-49. Paratypes: same locality and date: 2 E, 1♂ (Figs. 3 ab), KT-MG-UL, MM: 2009-49; Dinoša, Cijevna River, N42°24’24.6”, E19°20’56.1”, 85 m, 29.05.2009, 1♂, 1♀ +O, (Figs. 1-2), KT-MG-UL, MM: 2009-66; 13.04.2010, 6L (Figs. 6-7), KT-MG-UL, MM: 2010-31. Zlatica, Morača River, N42°28’40.2”, E19°18’19.8”, 50 m, 2010.04.17., 3L, KT- MG-UL, MM: 2010-40. ALBANIA, Librazhd district, Qukës Shkumbin, Shkumbin River, N41°05’45.7”, E20°26’34.0”, 380 m, (2006/4), 09.04.2006, 1 E, EZ-FZ-HA-MD, HNHM: PLP 2184; Pukë district, Mertur, Mertur Stream at the influence to Koman Lake, N42°13’36.8”, E19°54’18.0”, 180 m, (2006/56), 15.04.2006, 1♀ +O, EZ-FZ-HA-MD, HNHM: PLP 2246; Sarandë district, Çikë Mts, Borsh, Borsh River N of the village, N40°03’57.1”, E19°50’53.5”, 35 m, (2008/18), 12.03.2008, 1E, 1♂, CSz-MD, HNHM: PLP 2525. GREECE, West Macedonia, Grevena regional unit, Aetia, Venetikos River, N40°04’27.9”, E21°12’06.0”, 973 m, (2006/114), 14.05.2006, 1♀ +O, DL-KJ-MD, HNHM: PLP 2135; Eleftherohori, Venetikos River, 24.04.1989, 1♀ +O, HB-SI, PMSL: 03220; N40°03’06.6”, E21°28’50.2”, 475 m, (2006/111), 13.05.2006, 1E, 1♀ +O, DL-KJ-MD, HNHM: PLP 2132; Kipourio, Venetikos River, 24.04.1989, 9E, 1♂, HB-SI, PMSL; Zakas, Venetikos River, N40°02’19.3”, E21°17’19.2”, 699 m, (2006/112), 14.05.2006, 1L, 1♂ (Figs. 4a, 5a), DL-KJ-MD, HNHM: PLP 2144; Thessaly, Trikala regional unit, Ambelia, Kalambaka, 20.04.1989, 9E, 6♂, 6♀, HB-SI (8E, 4♂, 4♀, O, PMSL: 03148; 1E, 2♂, 2♀, O (Fig. 10), CGV); Kastania, Kalambaka, 20.04.1989, 7E, 1♂, HB-SI, PMSL: 03141; Kato Palagokaria, 19.04.1989, 2♀ +O, HB-SI, PMSL: 03119; Longiai, 19.04.1989, 3♀ +O, (in very poor condition), HB-SI, PMSL: 03126; Karditsa regional unit, Sarantaporo, small river S of the village, N39°09’13.9”, E21°49’50.7”, 700 m, (2011/39), 08.05.2011, 1♂, KJ-MD-SzT-UZs, HNHM: PLP 3680; Central Greece, Phthiotis regional unit, Agios Georgios, Sperchios River W of the village, N38°57’00.5”, E21°56’42.7”, 365 m, (2011/35), 08.05.2011, 1♂, 1♀ +O, KJ-MD-SzT-UZs, HNHM: PLP 3669; Timfristos, Sperchios River, (207), 29.04.1989, 1♀ +O, HB-SI, PMSL; Phocis regional unit, Vardousia Mts, Stromi, 26.04.1990, 1E, 1♀ +O, HB-SI, PMSL: 03212; Giona Mts, Lefkaditi, NW of Amfissa, 15.04.1987, 4♂, 2♀, O, Drosopoulos, PMSL: 03300.
Diagnosis. Head of the imago lacks yellow pattern by the M-line. Male macropterous, paraproct sclerite with long and straight apical part, apex angled. Female subgenital plate narrow. Larval hind femur long and narrow, last sternites with distinct setation. Egg with flower-like anchor, shape egg-like with cutoff base, FCIs distinct only on opercular part.
Description (Figs. 1-2). Dark brown with distinct yellow markings. A small sized Perlodes. Body length: males 12.5-18 mm, females 14.5-20.5 mm; forewing length: males 11.5-14.5, females 15-19.5 mm.
Dorsal part of head brown with two large pale patches (Fig. 1). One is a crown or tulip-shaped pattern on the occiput that laterally reaches the midline of the dark compound eyes, then deeply incised while central part pointed up to the postfrontal suture. Anterior pale patch is oval, delimited by the three, yellow ocelli. Occipital rugosities, tentorial callosities and M-line indistinct. Ventral part of head yellow, antennae and palpi brown.
Pronotum brown with a median longitudinal yellow stripe (Fig. 1), prothorax ventrally yellow besides dark brown rhomboid or arrow-shaped dark patch anterior to furcasternum. Dorsal part of meso- and metathorax dark brown, ventrally mostly dark brownish. Legs all brown, wings normal sized, veins dark brown.
Abdominal segments 1-4 divided by pleural membrane (as well as in larvae). Abdomen dorsally brown; males bear transverse pale patches on tergites IX–X, paired medial spots on tergite VIII, these may be present also on tergites VI–VII. Abdominal sternites brown, gradually darkened towards apex in males (transverse pale patches may be present medially); in females generally yellow while sternite I brown, sternites II-VII with a large anteromedial and variable lateral brown patches. Cerci brown in both sexes.
Male genitalia (Figs. 3a, b, 4a, 5a). Tergite X undivided, not raised. Paraproctal sclerite in ventral view with long and straight apical part that gradually narrows towards its apex; sides parallel and keeled beneath the apex that is strongly angled (120°) and sharply pointed (Figs. 3a, 4a). Apical part of paraproctal sclerite straight also in ¾ ventrolateral view, while apex above angle forms a nearly half curve (Figs. 3b, 5a).
Female genitalia (Fig. 2). Subgenital plate pale, as wide as 3/5 of the abdomen at its base; nearly three time wider than long. Rectangular or trapezoid with rounded corners, posterior margin straight or slightly convex, occasionally medially notched. Sternite VIII bears two large brown patches near the subgenital plate base, sternite IX bears paired dark brown spots laterally.
Larva (Figs. 6-7). Pale with brown pattern. Pattern of head and pronotum consist of brown marks on yellow ground as illustrated (Fig. 6). Lacinia generotypic. Mediodorsal row of long, apically blunt hairs run from postfrontal suture to end of tergite 10; length of hairs one third of corresponding tergal length. Hind femur long and narrow, ratio of length and width is 4.5:1. Row of marginal swimming hairs complete on both femur and tibia, nearly as long as femur’s width and one and half longer than tibia’s width. Apical row of setae on tergites as long as one tenth of corresponding tergite; setae mixed with blunt hairs similar to those of the mediodorsal row, their length 2-4 times longer than setae. Sternite 8 with medially incomplete apical row of setae, row complete on sternites 9-10.
Additional setae present on medial part of sternites 8-10 up to a quarter or half their length; these setae may be absent on sternites 8-9. Sternite also armed with long hairs curved outwards. Paraprocts lack distinct setation, but rarely with 1-2 strong setae (Fig. 7).
Egg (Figs. 8-11, 16e). Typical of the Perlodini tribe, trilateral (Figs. 8-9, 16e). Length 400 µm, width 300 µm. Shape egg- like with cut-off base, wider than the 2/3 of its length (Fig. 8); triangular in apical view (Fig. 9). Collar lacking. Anchor with several rows of rounded, petal-like plates on the disc edge; globular bodies arranged in 3-4 peripheral rows just inside the petal-like plates, anchor surface wrinkled (Figs. 10-11). Chorion covered with tiny warts; ornamentation of polygonal FCIs distinct on operculum but hardly visible on basal part (Fig. 8-9). Micropyles placed in a transverse row around midlength, not raised (Fig. 8).
Affinities. Size and head pattern of the new species is similar to Perlodes dispar. Both species lack the distinct, yellow C or V-shaped pattern by the M-line, characteristic for P. intricatus, P. jurassicus and P. mortoni. Females separate themselves from P. dispar and all the European species by their narrower subgenital plate. P. dispar male is micropterous while P. floridus is fully winged. Male paraprocts reminiscent of P. microcephalus in ventral view (Zwick 1997:494., Fig. 6a), but sclerite has a distinct apical angle in P. floridus but is gently curved in P. microcephalus. Paraproctal sclerites are also distinctly curved in ¾ ventrolateral view in comparison with the other European species: P. dispar, P. microcephalus (Marten 1991:400., Fig. 10), P. intricatus, P. jurassicus (Knispel et al. 2002:186., Figs. 1, 4).
Identification of Perlodes larvae are not yet clear. Nevertheless, the larva of P. floridus seems to be distinctive by the setation of the three last sternites and the long, narrow hind femur.
Egg of P. floridus is rather distinctive and can be easily separated from the known Perlodes species by its size, shape and anchor: Figs. 16 a-f; P. dispar, P. microcephalus (Kovács & Murányi 2008:117., Fig. 2a- b), P. frisonanus (Isobe 1988: 34., Fig. 9), P. intricatus, P. jurassicus (Knispel et al. 2002:187., Figs. 7, 10), P. mortoni (Zwick 2011:294., Fig. 5 mo-1-7).
Etymology. The name floridus (from the Latin word flora, meaning flower) refers to the flower-like anchor of the egg that distinguishes the new species from the hitherto known Perlodes.
Ecological notes. The specimens were found in different types of rivers between 35 and 975 m a.s.l. (Figs. 17-24). All of them have fast flow, even in the low altitudes, and stony substrate, but width varies between 5 to 20 meters. Larvae were found under big stones in the strongest current, life cycle seems to be one-year like in other Perlodes species. Adults occurred between 12th of March and 29th of May, and were captured on stones and vegetation close to the bank. Due to the wide range of its habitats, it was found together with many other stoneflies. The most species rich locality is the Sperchios River at Agios Georgios, where earlier (10.04.1967) the following species were found (Berthélemy 1971): Brachyptera beali, B. helenica, B. graeca, B. phthiotica (?), Brachyptera sp., Protonemura mattheyi, Amphinemura sperchiana, Leuctra sp., Perlodes microcephalus, Isoperla tripartita, Perla marginata, P. pallida, Chloroperla sp. (tripunctata ?); in 2010 we found there the species Leuctra moreae, Protonemura intricata, Perla pallida. In the other rivers P. floridus shares the habitat with the further species: Brachyptera risi, Leuctra olympia, Capnia nigra, Amphinemura quadrangularis, Nemoura cinerea, Besdolus imhoffi, Isoperla grammatica, Perla abdominalis, Dinocras sp., Eoperla ochracea, Chloroperla tripunctata, Siphonoperla sp.
Remarks: Berthélemy (1971) cited P. microcephalus from the Sperchios River where we found P. floridus only. Unfortunatelly, we had no access to study the specimens held in the Toulouse Museum, France.