Minagrion ribeiroi ( Santos, 1962 )

Vilela, Diogo Silva, Anjos-Santos, Danielle, Koroiva, Ricardo, Cordero-Rivera, Adolfo & Guillermo-Ferreira, Rhainer, 2020, Revision of the genus Minagrion Santos, 1965 (Odonata: Coenagrionidae), Zootaxa 4786 (2), pp. 176-198 : 188-190

Minagrion ribeiroi ( Santos, 1962)

Figs. 1e (♂ hab), 2i–j (♂ and ♀ tub), 3q–t (♂ app), 4e (♂ lig.), 5i (♀ hab), 6e (♀ lob), 7d (♀ ptx), 8e–f (♂ app, lost holotype), 9g–i (♀ lost allotype), 10e (alive ♂ specimen)

Telagrion ribeiroi, Santos (1962) : 1 −6 (original description ♂ and ♀)

Minagrion ribeiroi, Santos (1965a) : 9 (transference from Telagrion to Minagrion );— Santos (1967): 8 (comparison with M. canaanensis );— Garrison (1991): 13 (synonymic list);— Carvalho & Nessimian (1998): 7 (habitats of immatures occuring in Rio de Janeiro State);— Costa & Mascarenhas (1998): 11 (Catalogues of the types housed in the MNRJ, comments);— Costa et al. (2001): 437, 440, 446 (species list);— Lencioni (2006): 172 (illustrated guide, distribution);— Garrison et al. (2010): 287, 289 (synonymic list, illustrations: Figs. 1852 and 1853 as M. mecistogastrum ).

Holotype ♂ and allotype ♀: BRAZIL, Rio de Janeiro State, Recreio dos Bandeirantes (Lagoa das Taxas), 14.ix.1960, N.D. Santos leg., in MNRJ [examined]

Specimens examined. Total: 108♂♂, 38♀♀. 74♂♂, 27♀♀, BRAZIL, Rio de Janeiro State, Recreio dos Ban- deirantes (Lagoa das Taxas), collected in diferent dates, as follows : 1♂, 2♀♀ 05.x.1961 N.D. Santos and J.P. Mach- ado leg., 6♂♂, 3♀♀ (paratypes) 21.ix.1960 N.D. Santos leg. (one ♂ paratype housed in FAAL) , 1♂ 22.ix.1963 N.D. Santos leg., 1♂, 1♀ 17.x.1965 N.D. Santos leg., 1♂ 12.xii.1965 N.D. Santos leg., 4♂♂, 4♀♀ 20.xi.1966 N.D. Santos leg., 11♂♂, 2♀♀ 07.i.1968 N.D. Santos leg., 2♂♂ 02.i.1965 N.D. Santos leg., 4♂♂, 1♀ 08.viii.1965 N.D. Santos leg., 2♂♂, 1♀ 13.viii.1964 N.D. Santos leg., 1♂, 1♀ 05.ix.1965 N.D. Santos leg., 9♂♂, 7♀♀ 19.ix.1965 N.D. Santos leg., 3♂♂ 29.viii.1967 N.D. Santos & J. Machado leg., 5♂♂ 01.ix.1968 N.D. Santos leg., 10♂♂, 1♀ 02.xi.1969 N.D. Santos leg., 12♂♂, 4♀♀ 26.xi.1969 N.D. Santos and J. Machado leg. and 1♂ xi.1969 N.D. San- tos and J. Machado leg., all in MNRJ ; 2♂♂, Rio de Janeiro State, Recreio dos Bandeirantes, 01.ix.1968,? leg., in MNRJ ; 3♂♂, Rio de Janeiro State, Recreio dos Bandeirantes, ‘ Inside the forest’, 06.ix.1962, J. Machado & O.A. Roppa leg., in MNRJ ; 1♂, Rio de Janeiro State, ‘ Canal das Taxas (forest)’, 05.x.1961, J. Machado, O.A. Roppa & H.F. Berla leg., in MNRJ ; 13♂♂, 5♀♀, Rio de Janeiro State, Restinga de Itapeba , Lagoinha das Taxas, collected in different dates as follows : 2♂♂ 02.viii.1964; N.D. Santos leg., 2♂♂, 1♀ 16.viii.1964 N.D. Santos leg., 9♂♂, 3♀♀ 21.ix.1969 N.D. Santos leg. and 1♀ 13.xi.1964 N.D. Santos leg., all in MNRJ ; 2♂♂, Rio de Janeiro State, São Ber- nardino, Estrada de Ferro Rio d’Ouro , 19.ix.1937, R . d’Almeida leg. in ABMM; 1♀, São Paulo State, Salesópolis (23°35’51” S, 45°43’41”, 1074 m asl), F.A.A. Lencioni leg., in FAAL .

Additions to the original female description. Head ( Fig. 5i ). Black dorsally, except for a pale occipital bar; labrum, anteclypeus, postclypeus, antefrons and postfrons yellow. Back of the head black.

Thorax ( Figs. 5i , 6e , 7d , 9g ). Posterior lobe of prothorax trilobed in dorsal view, all lobes subequal in size; lateral and middle lobes slightly erected in lateral view; lateral margin of prothorax widens greatly towards the base; notopleural suture a nearly straight line.

Legs ( Fig. 5i ). Pale, spination brown, tibial spines longer than the space between them.

Wings ( Fig. 5i ). Hyaline with brown parallelogram pterostigma, occupying one cell; 9 Px in HW, 11 Px in FW; CuA extending for 9 cells distal to vein descending from subnodus in FW and HW; MP not reaching wing posterior margin and merged to MP&AA in FW and HW.

Abdomen ( Figs. 2j , 5i , 9 h–i). Tubercle roughly triangular as in the male, significantly smaller, slightly excavated posteriorly. Ovipositor surpasses the posterior margin of S10 for a distance shorter than this segment and does not reach the level of cercus.

Measurements. Total 33−35; abdomen 27−29; FW 18−19; HW 16.6−18.

Diagnosis. Male cercus shorter than S10 ( Figs. 3 q–t, 8e–f; shared only with M. mecistogastrum ), wide ventrobasal portion occupying at least 3/4 of cercus length, in other species, the ventrobasal portion occupies 1/2 of cercus or less; cercus with one strong tooth at its apex; paraproct with acute apex, pointed posteriorly (shared with M. caldense ); segment one of genital ligula with a pair of digit-like lateral sclerotized processes, similar to lobes, in flexure; small inner fold sub triangular in lateral view, proximal to flexure; segment two very short, almost at level of the inner fold, with an entirely straight apex ( Fig. 4e ); tubercle triangular with acute apex, smaller in females ( Fig. 2i ). Posterior lobe of female prothorax trilobed ( Fig. 6e ), each lobe subequal in size, slightly erected in lateral view ( Fig. 7d ); lateral margin of prothorax wider at base ( Fig. 7d ; shared with M. canaanense ); notopleural suture nearly a straight line; tubercle roughly triangular, smaller than in male ( Fig. 2j ).

Distribution. This species is only recorded in the States of Rio de Janeiro and São Paulo, Brazil, in the Atlantic Forest region. Although this species was numerous in MNRJ collection, it seems to be one of the rarer Minagrion species in collections and is also rarely encountered in the field.

Figures

FIGURE 1. Male habitus: (a) caldense, São Roque de Minas, at ECOEVO; (b) caldense, Poços de Caldas, at FAAL; (c) canaanense, Santa Tereza, at FAAL; (d) mecistogastrum, Salesópolis, at FAAL; (e) ribeiroi, Recreio dos Bandeirantes PARATYPE, at FAAL; (f) waltheri, São Gonçalo do Rio Preto, at ABMM.

FIGURE 2. S1 tubercle; (a) ♂ caldense, Poços de Caldas, at FAAL; (b) ♂ caldense, São Roque de Minas, at LESTES; (c) ♀ caldense ALLOTYPE, Poços de Caldas, at MNRJ; (d) ♀ caldense, SCNP, at ECOEVO; (e) ♂ canaanense, Santa Tereza, at FAAL; (f) ♀ canaanense ALLOTYPE, Santa Tereza, at MNRJ; (g) ♂ mecistogastrum, Salesópolis, at FAAL; (h) ♀ mecistogastrum, Salesópolis, at FAAL; (i) ♂ ribeiroi, Recreio dos Bandeirantes PARATYPE, at FAAL; (j) ♀ ribeiroi, Salesópolis, at FAAL; (k) ♂ waltheri, São Gonçalo do Rio Preto, at ABMM; (l) ♀ waltheri, São Gonçalo do Rio Preto, at ABMM.

FIGURE 3. Male anal appendages; (a–d) ♂ caldense, Poços de Caldas, at FAAL; (e–h) ♂ caldense, São Roque de Minas, at LESTES; (i–l) ♂ canaanense, Santa Tereza, at FAAL; (m–p) ♂ mecistogastrum, Salesópolis, at FAAL; (q–t) ♂ ribeiroi, Recreio dos Bandeirantes PARATYPE, at FAAL; (u–x) ♂ waltheri, Jaboticatubas, at FAAL.

FIGURE 4. Male genital ligula; (a) caldense, Poços de Caldas PARATYPE, at MNRJ probably lost; (b) caldense, SCNP PARA- TYPE of M. franciscoi, at ABMM; (c) canaanense, Santa Tereza, at RWG; (d) mecistogastrum, Cachoeira de Macacu, at RWG; (e) ribeiroi, Recreio dos Bandeirantes, at RWG; (f) waltheri, São Gonçalo do Rio Preto, at ABMM.

FIGURE 5. Female habitus; (a–c) juvenile caldense, SCNP, at LESTES; (d–f) mature caldense, SCNP, at LESTES; (g) caldense, Poços de Caldas PARATYPE, at ABMM; (h) mecistogastrum, Salesópolis, at FAAL; (i) ribeiroi Salesópolis, at FAAL; (j) waltheri, São Gonçalo do Rio Preto, at ABMM.

FIGURE 6. Female posterior lobe of prothorax; (a) caldense, Poços de Caldas ALLOTYPE, at MNRJ; (b) caldense, SCNP, at ECOEVO; (c) canaanense, Santa Tereza ALLOTYPE, at MNRJ; (d) mecistogastrum, Salesópolis, at FAAL; (e) ribeiroi, Salesópolis, at FAAL; (f) waltheri, São Gonçalo do Rio Preto, at ABMM.

FIGURE 7. Female prothorax in lateral view; (a) caldense, Poços de Caldas PARATYPE, at ABMM; (b) canaanense, Santa Tereza ALLOTYPE, at MNRJ; (c) mecistogastrum, Salesópolis, at FAAL; (d) ribeiroi, Salesópolis, at FAAL; (e) waltheri, São Gonçalo do Rio Preto, at ABMM.

FIGURE 9. Female structures of Minagrion allotypes probably lost during the fire at MNRJ in 2018; (a–c) caldense, Poços de Caldas; (d–f) canaanense, Santa Tereza; (g–i) ribeiroi (Telagrion ribeiroi), Recreio dos Bandeirantes; (j–l) waltheri (Telagrion serracipoense), Jaboticatubas.