Micrathyria paulsoni, González-Soriano, 2020

González-Soriano, Enrique, 2020, A new species of Micrathyria Kirby, 1889 from México and Central America (Anisoptera: Libellulidae), with a key to Mexican species, Zootaxa 4718 (2), pp. 184-190 : 184-187

Micrathyria paulsoni sp. nov.

Fig. 1 (male and female) Fig 2 . (a–f) (structural characters). Fig. 3 (a–c) (structural characters). Fig. 4 (distributional map).

Specimens examined. 23 ♂♂, 6 ♀♀. Types. Holotype ♂: MÉXICO, Veracruz State, Laguna de Santo Domingo, Huatusco (19.1593 -97.0045), 9 July 2000, E. González-Soriano & L. E. González-Figueroa leg . Paratypes: MÉXI- CO, Aguascalientes, 1 ♂ Puente El Refugio, carretera a Los Arquitos, Jesus María , 1888 m asl, 3 September 2005 J. Escoto Moreno, leg. [ CNIN] ; Colima, 1 ♀ Laguna La María , 20 July 2003 E. González leg [ CNIN] ; Jalisco, 2 ♂♂ El Limón, Municipio San Buenaventura [19.7935, -104.0554], 720 m asl, 4 August 1997, E. González & A. Morales leg. [ CNIN] ; Michoacán, 1 ♂, 1 ♀ La Zararacuita, Uruapan , 5 May 1988, E. González leg. [ CNIN] ; Morelos, 3 ♂♂ Las Estacas, 30 April 1986, E. González & V. García leg. [ CNIN] ; Jiutepec , 1 ♂ Fraccionamiento Las Fincas , 1 October 1989, E. González leg. [ CNIN] ; Oaxaca, 1 ♂ San Miguel Cuevas, Santiago Juxtlahuaca , 1 July 2016, A. Juárez Jiménez leg ; Querétaro, 3 ♂♂ Laguna de Pizquintla, Municipio de Jalpan (21.1852777, -99.5150), 1010 m asl, 22 April 2014, E. González-Soriano & H. Ortega-Salas leg. [ CNIN] ; Veracruz, 8♂♂, 2♀♀ Laguna de Santo Domingo, Huatusco (19.159314, -97.004555), 23 August 1987, R. Novelo leg ; 2 ♂♂, 1 ♀ 9 July 2000 E. González & L. E. González leg. ; 2 ♂♂ 11 July 2000 E. González, L. E. González & A. González leg. [ CNIN] ; 4 ♂♂, 1 ♀ Parque Javier Clavijero, Jalapa 18 June 1992, E. González leg. [ CNIN]. COSTA RICA, Limón Prov., 1 ♂ Guapiles , in forest 1000’ (10.2038, -83.8406), 7 July 1967, M.J. & D.N. Westfall leg. [ CNIN] . NICARAGUA,

Jinotega Dept., 2 ♂♂, 1 ♀ Hotel Selva Negra , (12.99944, -85.90830), 1000 m asl, 3 August 2001, E. González- Soriano leg. [CNIN].

Etymology. This species is named paulsoni (noun in the genitive case) after Dr. Dennis Paulson for his enormous contributions to the field of Neotropical odonatology.

Description of holotype. Head. Labium cream; labrum, clypeus and 0.75 of vertical surface of antefrons cream-whitish scarcely covered by dark brown hairs, remaining 0.25 of antefrons and postfrons black; vertex with metallic blue reflections; a pair of low lateral subconical tubercles on ocellar ridge; occiput black, polished, hairy along straight posterior margin; antennae black.

Thorax. Prothorax: anterior and middle lobes pale brown, the former with a pale subrectangular median bar; posterior lobe dark brown with posterior margin slightly sloping and fringed by long yellow hairs. Pterothorax ( Fig. 2 a ): dark brown with green stripes and spots as follows: 1) a pair elongated spots on antealar sinus and second pair in front of antealar ridge, 2) mesepisternal stripes narrow extending 0.75 length of mesepisternum not reaching antealar sinus, 3) an oval spot in front of anterior end of middorsal thoracic carina, 4) a narrow imperfect stripe above basal part of mesopleural suture, 5) a wide stripe on upper part of mesepimeron, 6) traces of stripe above basal part of metapleural suture; 7) wide stripe occupying lower part of metepimeron. Legs: Coxae and trochanters pale brown, femora black (excepting basal external surface of profemora which is pale brown), tibiae and tarsi black.

Wings. Hyaline, arculus slightly anterior to second antenodal; FW subtriangle three celled, triangles two celled in all wings. Ax in FW 9 ½, HW 7 (LHW) and 8 (RHW), Px in FW 8 (LFW) and 7 (RFW), HW 8; FW triangles 2 Cx, subtriangles 3 Cx, HW triangle free; FW discoidal field with two row of cells.

Abdomen. Black with green or pale markings as follows: lateral areas of S1 green, S2 medium brown laterally, S3 with a pale dorsolateral stripe reaching TC and small spot post TC; S4–S5 lacks TC but with both pale areas occupying same position, S6 black with only a small vertical basal bar, S7 with large dorsolateral rectangular spots occupying 0.7 length, S8–10 black, unspotted. Hamuli pale brown, in lateral view with outer branch surpassing the height of genital lobe ( Fig. 2 b ), in dorsal view with tips converging and denticulate ( Fig. 2 c ), inner branch short with tips diverging, anterior laminae low ( Fig. 2 b ). Cerci black, in lateral view slightly concave in basal half with a slight triangular ventral angulation at 0.7 of cerci length preceded by several shallow undulations ( Fig. 2 d ); tips sharply pointed, in dorsal view slightly widened from base to 0.6 length, then abruptly narrowing and ending in an acute tip ( Fig. 2 e ); epiproct in ventral view, wider at base tapering into a blunt, emarginate tip ( Fig. 2 f )

Genitalia. Distal segment of vesica spermalis with an upright median process, ending in an acute point; posterior lobe short, subcylindrical ( Fig. 3 a, b ).

Measurements. TL 36.89, AL 25.03, HWL 27.84, cerci 2.06, EP 1.87.

Description of female ( Fig. 1 ). Coloration similar to male, but pale colors brownish and more extensive than male. Head similar except frons and occiput rusty brown, vertex dark brown except top which is rusty brown. Thorax: pale colors medium brown, pale stripes yellowish, wings slightly smoky at tips. Abdomen: pale stripes brownish, on S3–6 larger than in male, spots on S7 wider. Vulvar laminae bilobed, extended posteriorly half the way the length of S–9 ( Fig. 3 c ).

Variations in paratypes. Males: Ax in FW 8–10 ½, in HW 7–9; Px in FW 6–9, in HW 7–9; triangle with 1–2 in FW; subtriangle with 2–3 Cx. Dimensions: TL 32.8–38 (35.8), AB: 22.5–25.7 (24.34), HWL:25.8–30.2 (28.83). Females: TL: 29.3–33.6 (32.05); AL 19.6–22.1 (21.08) HWL: 26.6–28.5 (27.82).

Additional localities (D. Paulson pers. comm.): MEXICO, Chiapas state: 9.2 mi N Jitotol, 6300 ft, 16 July 1965 and 24 August 1967; 21.2 mi E of Mex. 190 on road to Lagunas de Montebello, 5000 ft, 14 July 1965; 11.4 mi N Ocozocoautla, 3200 ft, 20 July 1965; 10.5 mi N Ocozocoautla, 3200 ft, 25 August 1967; Morelos state, ca 2 mi N, 6 mi W on Mex. 115, 4300 ft, 21 June 1966.

COSTA RICA, Cartago, 2 km E Sitio de Mata , 4000 ft, 2 August 1963 ; Cartago, Tapantí , 3900 ft, 26 July 1966 & 23 June 1967 ; Cartago, Instituto Interamericano de Ciencias Agricolas , SE of Turrialba, 2000 ft, 2 August 1966 ; Puntarenas, 5 mi S San Vito , 4700 ft, 27 April 1967 and 16 March 1968 .

It is widespread and common in the uplands of Costa Rica. I assume it occurs in all the intervening countries but has not been found yet (or is misidentified in some collections) (D. Paulson pers. comm.)

Diagnosis. By its enlarged hamular process, M. paulsoni belongs to the so-called “ Micrathyria didyma ” group also including M. hypodidyma Calvert, 1906 ; M. laevigata Calvert, 1909 ; M. pseudhypodidyma Costa, Lourenço & Viera, 2002; M. sympriona Tennessen, 2000 and M. venezuelae De Marmels, 1989 . All species of this group have two wide green stripes at sides of pterothorax, except M. didyma (Selys in Sagra, 1857) who has three.

Within this group, M. paulsoni is most closely related to M. laevigata and M. venezuelae by the morphology of cerci and also of the distal segment of vesica spermalis. In these three species the ventral margin of cerci is concave in basal half. Viewed laterally the cerci in M. paulsoni have a slight ventral angulation preceded by shallow undulations. In M. venezuelae there is a prominent and denticulated inferior angle while in M. laevigata no angulation is visible. Also in these three species there are two apical projections on distal margin of vesica spermalis named: the median process and the posterior lobe. In M. paulsoni posterior lobe is thicker, shorter and subcylindrical ( Fig. 3 a,b ). On the other hand in both M. venezuelae and M. laevigata the posterior lobe is longer and more “finger-like” [for comparison for M. laevigata (see Fig. 25 Santos 1955) and for M. venezuelae (Fig. 195 De Marmels 1989)]. Median process is bifid in M. hypodidyma and M. pseudhypodidyma ( M. paulsoni and relatives have this structure entire). Finally, although in M. sympriona distal segment of vesica spermalis is similar to those of M. paulsoni and relatives its narrow and linear cerci separates M. sympriona from all members of the previous group (see Fig. 9 Tennessen 2000).

M. paulsoni can also be separated from both M. venezuelae and M. laevigata by having the arculus situated before the second antenodal crossvein (in the latter two species the arculus is situated either at the second or posterior to the second antenodal crossvein).

Finally females of M. paulsoni have a shallow excision on the vulvar laminae with short and low lateral lobes ( Fig. 3c ), in contrast females of both M. venezuelae and M. laevigata have a deep V-shaped vulvar lamina with conspicuous semicircular lobes.

For further discussion of the Micrathyria didyma group see also Tennessen (2000).

Remarks. Micrathyria paulsoni sp. nov. occurs in a wide range of altitudinal and biotic conditions in Mexico. At medium altitudes it can be found in shaded ponds surrounded by cloud forest at the type locality near Huatusco, Veracruz (1450 m asl) but in San Buenaventura, Jalisco (750 m asl) it also occur in open ponds surrounded by tropical deciduous forest. In the vicinity of Xalapa, Veracruz it can also be found in artificial ponds coexisting with species such as Cannaphila vibex (Hagen, 1861) , Libellula herculea Karsch, 1889 and Acanthagrion quadratum Selys, 1876 among others.

In spite of their wide distribution in at least six Mexican States along the Neovolcanic Transverse Belt, M. paulsoni remained for many years undiscovered by researchers within the Mexican territory. Its presence in Nicaragua and Costa Rica, also opens the possibility that this species was confounded for many years with M. laevigata which apparently has a more South American distribution. However, more studies are needed to confirm or refuse the overlapping of both species in Central America.

Figures

FIGURE 1. Micrathyria paulsoni sp. nov., male and female in tandem, Parque Javier Clavijero, Xalapa.

FIGURE 2. Micrathyria paulsoni sp. nov., male paratype: a) pterothorax, b) hamuli lateral view, c) hamuli ventral view, d) cerci, lateral view, e) cerci, dorsal view, f) epiproct.

FIGURE 3. Micrathyria paulsoni sp. nov., male paratype: a) vesica spermalis, lateral view, b) vesica spermalis dorsal view, c) Micrarthyria paulsoni female paratype: vulvar lamina.

FIGURE 4. Distributional map of M. paulsoni sp. nov., in México and Central America.