Euricrium unimacula ( Lane, 1955 ) Lane, 1955

Amorim, Dalton De Souza & Schnell, Guilherme, 2017, A new species of Euricrium Enderlein from southern Brazil, new records for E. varians (Lane), a new combination, and a key for the Neotropical species of the genus, Zootaxa 4231 (3), pp. 327-340 : 335-336

Euricrium unimacula ( Lane, 1955) , comb.nov.

( Figs 18, 19 )

Euricrium unimacula ( Lane, 1955) : 257 ( Zygoneura ). Type-locality: Brazil, State of Santa Catarina, Seara, Nova Teutônia. Distribution: southern Brazil and higher altitudes in southeastern Brazil. References : Amorim (1992: 68), catalogue. Holotype female, MZUSP.

Material examined. Holotype female, Brazil, State of Santa Catarina, Seara (Nova Teutônia) 27° 11’ S, 52° 23’ W, “193...”, F. Plaumann leg. Additional specimens. State of Santa Catarina: 1 female, same data as holotype, but August, 1965 ; 1 female, same data, but August, 1970 ; 3 females, same data, but September, 1970 ; 4 females, same data, but June, 1971 ; 1 female, same data, but July, 1971 ; 3 females, same data, but August, 1971 ; 14 females, same data, but September, 1971 ; 2 females, same data, but October, 1971 ; 1 female, same data, but June, 1972. State of São Paulo : 1 female, Embu, J. Lane, leg., December, 1952 ( MZUSP).

Redescription: Body length: 2.9 mm. Pubescence short, mostly shinning.

Female ( Fig 18). Head. Head capsule blackish brown, rounded, only slightly higher than long, mouthparts not elongated; setation short, sparse. Three ocelli present, mid ocellus slightly larger than lateral ocelli. Eyes reniform, eye bridge complete, narrow, 2 facets wide, with fine interommatidal setulae. Antennae shorter than abdomen; scape and pedicel dark, subglobular, setose, scape slightly reddish-brown. Flagellum dark; 14 flagellomeres, first flagellomere about as long as remaining flagellomeres, terminal flagellomere about as long as penultimate; flagellomere body cylindrical, about 1.9 times longer than width, distal neck 0.14 times length of flagellomere body. Flagellum bare of microtrichia, setation on flagellomere shorter than flagellomere width ( Fig. 5 ). Face wide, setose; clypeus narrower, clearly separated from face, setose. Labrum beak-like, subtriangular, well sclerotized, with some very few setae. Maxillae with lacinia absent. Maxillary palpus yellowish-brown, elongate, 3 palpomeres; first palpomere only partially sclerotized, bare; palpomeres 2–4 setose, palpomere 2 with three setae and numerous short hyaline sensory hairs; palpomere 3 widest, with four setae; fourth palpomere longest, with a pair of distal longer. Labial palpus developed; labellum 1 non-setose, much smaller than 2; labellum 2 with numerous, partly spine-like. Thorax. Scutum and scutellum blackish brown, shinning, slightly arched in profile, anterior parapsidal suture and median transverse suture absent, some few setulae present at the antero-lateral margin and six fine setae along the lateral margin, no dorso-centrals, no acrosticals. Scutellum clearly separated from scutum, bearing some setae of different lengths in an irregular row. Pleural sclerites dark brown, shining, except for laterotergite and mediotergite, blackish brown and dull. Postpronotum bare; antepronotum with a single long, fine seta at posterior margin. Proepisternum with sparse fine setae. Proepimeron subtriangular, elongate, extending into antero-dorsal corner of katepisternum. Anepisternum relatively small, largely separated from proepisternum by membranous area, entirely devoid of setation; anepisternal cleft distinct, complete. Katepisternum subtriangular, larger than anepisternum, bare, pre-episternum 2 slender. Mid-pleural pit evident, less sclerotized than surrounding sclerite. Mesepimeron with deep cleft dorsally. Metepisternum with wide dorsal membranous area around posterior spiracle. Metepimeron very narrow. Openings of anterior and posterior spiracles without any striking features. Laterotergite drop-shaped, only slightly projected outwards. Suture between mediotergite and laterotergite distinct. Mediotergite in profile only slightly arched. Halter with stem and knob subequal in length, with fine setae, stem yellowish, knob brown. Legs. Anterior coxa, femora, and tibia creamy yellow, setae yellowish or brownish yellw, tarsus darkening to tip. Mid coxa yellowish brown, darker at posterior half, remainder of leg colored as foreleg. Hind coxa brown, femur yellowish brown on basal two thirds, brownish on distal third, tibia yellowish brown with short dark setation, tarsus dark yellow, darker to tip. Fore tibia with distal comb with 9 setae, but no depression. Tibial spurs 1:2:2, mid and hind tibiae with one of the spurs slightly shorter. Pretarsal claws slightly curved and with discrete row of small teeth. Empodia well developed. Wing ( Fig. 19 ). Length, 3.3 mm, 3.0 times longer than wide. Membrane with basal third and distal third translucent, a dark maculation over mid third, with a noticeable extension of base of medial fork, no darkened area at tip of wing. Membrane densely covered with short microtrichia. C ending very close to wing apex; Sc short, ending free before origin of M-fork; R1 slightly longer than r-m, Rs relatively long, ending slightly beyond tip of M2, first sector of Rs short, transversal; r-m just over twice length of first sector of Rs; M1 arched, medial fork branching slightly beyond mid of wing, quite elongate. First sector of CuA very short; CuA2 sharply bent on distal third; CuP extending beyond mid of CuA; A1 very short; A2 absent. Abdomen: Sclerites densely covered with setae, tergites and sternites brown.

The holotype is in good conditions—the tip of the left antenna and the left hind leg are missing; the wings have minor damages. The original description is enough for identification. We add here details missing in Lane’s (1955) description. There is no question that the species belong in the genus Euricrium and a new combination is proposed here. This species is quite similar to E. edwardsi , but some features help to clearly separate them. The most conspicuous is the absence of a light brown macula at the tip of the wing in E. unimacula . As well, E. unimacula has as a longer R1 and a shorter r-m. Besides the material from the holotype, we examined a good number of additional specimens from the type-locality, and one female from Embu, in the State of São Paulo.

Figures

FIGURE 19. Euricrium unimacula, female, holotype, wing.

FIGURES 5 – 8. Basal flagellomeres (arrow indicates flagellomere 4). 5. Euricrium edwardsi, sp. n., male paratype. 6. E. edwardsi, sp. n., female paratype. 7. E. varians (Lane), male from Araucária, State of Paraná. 8. E. varians (Lane), female from Araucária, State of Paraná.