Leptagrion itabaiana, Vilela, Lencioni & Santos, 2021

Farias, Antonio Bruno Silva, Ventura, Iza Mayra Castro, Vilela, Diogo Silva & Santos, Jean Carlos, 2024, Description of the female of Leptagrion itabaiana Vilela, Lencioni & Santos, 2021 (Odonata: Coenagrionidae) from Serra of Itabaiana National Park, Northeastern Brazil, Zootaxa 5443 (2), pp. 273-280 : 275-279

Description of Leptagrion itabaiana female

( Figures. 2a–e ; 3i–j ; 4a–c )

Material examined: 1♀ (B0756) (in copulation, described here), Brazil, Sergipe, Areia Branca, Serra of Itabaiana National Park , -10.7499, -37.3426, 221 m asl), 24.v.2023, A.B.S. Farias leg. (UFS) . 1♀ (B0757), Brazil, Sergipe, Areia Branca, Serra of Itabaiana National Park , -10.7499, -37.3426, 221 m asl), 24.v.2023, A.B.S. Farias leg. (UFS) .

Head ( Figs. 2a–d ). Mandibles with two apical teeth, inner teeth slightly smaller than outer ones; labium pale brown, labrum orange-brown with a basal black stripe in shape of “m”; base of mandibles and genae pale colored, apex of mandibles brown; anteclypeus trilobed; postclypeus with smoothly convex central anterior margin, light blue with a black median stripe; antefrons pale colored with a black apical stripe; postfrons with gentle central depression; well-pronounced ocelli; remainder of head with cupreous metallic reflections, except for two small pale spots lateral to the lateral ocelli; the back of the head is black, fading to pale blue ventrally; eyes dark dorsally and bluish ventrally.

Thorax ( Figs. 2a, c , and d). Prothorax:Anterior lobe of the prothorax light blue; medial lobe brown dorsally, light blue laterally; posterior lobe light blue, with a large medial convexity, tapering laterally. Pterothorax: Pterothorax with a cupreous metallic middorsal carina covering most of mesepisternum; remainder of mesepisternum blue, including mesopleural suture; mesepimeron orange, posteriorly blue; mesinfraepisternum orange anteriorly, light blue posteriorly; metepisternum pale colored, with a thin apical blue stripe, a thin medial orange stripe, and a thin basal blue stripe; remainder pale colored. Coxae and trochanter pale colored; legs mostly pale with dark brown femoral areas.

Wings ( Fig. 2a ). Hyaline: Pt dark brown, rectangular, with pale borders, overlying slightly more than 1 cell in all wings; 7 Px in LFW and 8 Px in RFW, and 8 Px in both HW; RP1 originates at Px 6 in all wings.

Abdomen ( Fig. 2a ). S1 dark brown dorsally, light blue laterally and pale ventrally; S2 dark brown dorsally, light blue laterally and pale orange ventrally; S3–7 predominantly brown, pale lateroventrally, with pale basal rings and black apical rings; S8 dark brown with pale spot ventrally; S9–10 predominantly brown.

Anal appendages ( Fig. 2e ). Cerci dark brown, shorter than S10; genital valve surpassing S10, ventral margin with bristles and a row of denticles; ovipositor and appendages dark brown.

Measurements. FW: 16.73; HW: 16.53; AL: 29.4; TL: 37.2.

Variations in the specimens. Females did not vary in the morphology of the prothorax and anal appendages. Slight differences in abdominal coloration were observed, which were likely related to intraspecific, age, and postmortem differences. The pterothorax of the type specimen had a long and distinct interpleural suture, while that of the other specimen was indistinct. The second female had 7 Px on all wings. Female specimens varied in size as follows: FW: 16.70, HW: 16.32, AL: 30.27, TL: 37.9.

Differential diagnosis. Within the Leptagrion species group, the closest congener to males is L. afonsoi Machado, 2006 ( Vilela et al. 2021b). Unfortunately, a description of females for comparison is still lacking. However, we compared our specimens with illustrations of other described congeneric females (e.g., L. aculeatum Santos, 1965 , L. andromache , L. dispar , L. elongatum Selys, 1876 , and L. vriesianum Santos, 1978 ; Figs. 3a–j ) ( Costa & Garrison 2001; Furieri et al. 2020; Lencioni 2006; Santos 1978). The genital valve of L. itabaiana extended beyond the posterior margin of S10 ( Fig. 2e ), as observed in L. aculeatum , L. elongatum , and L. vriesianum . However, the morphology of the posterior lobe of the prothorax in L. itabaiana resembles that of L. andromache ( Figs. 3c ), differentiated by the straight posterior margin and thinner lateral margins in L. itabaiana ( Figs. 3i–j ), whereas in L. andromache , the posterior margin has a slight concavity, and the lateral margins of the posterior lobe are wider ( Fig. 3c ). The posterior lobe of L. vriesianum was also similar to some degree, but the concavity in the posterior margin was strongly accentuated ( Fig. 3h ).

Ecological and biological notes. This species was collected associated with bromeliad tanks [ Aechmea and Hohenbergia species ( Bromeliaceae ) ( Fig. 4d )], the same habitat in which the males compete with L. garbei in the Serra of Itabaiana National Park. On the occasion that resulted in the description of the species (February 2021, dry season), no females were found, even with intensified searches. However, at the start of the rainy season (May 2023), it was possible to collect females during the mating process. It is important to highlight the low level of sexual dimorphism in L. itabaiana ( Fig. 4a–c; e ).

Final remarks. To date, among the 20 known species of the genus Leptagrion , 13 females have been described. Here, we present a description of the 14th female of the genus. Leptagrion itabaiana female was diagnosed two years after the description of the male. We emphasize the importance of conserving these habitats and the need for further studies to understand the biology and ecology of these organisms, as seasonality appears to be a determining factor in the phenology of female L. itabaiana , which appeared in May, as well as female L. garbei , which was found in February in the region.

Figures

FIGURE 2. Leptagrion itabaiana, from the Serra of Itabaiana National Park, Sergipe, Brazil: (a) lateral view of habitus; (b) antero-dorsal view of head; (c) dorsal view of head and lateral view of prothorax; (d) dorsal view of prothorax and pterothorax; and (e) lateral view of S8–10.

FIGURE 3. Posterior lobe of the prothorax in females described for the genus Leptagrion: L. aculeatum - (a) dorsal view, (b) lateral view; L. andromache - (c) dorsal view; L. dispar - (d) dorsal view, (e) lateral view; L. elongatum - (f) dorsal view, (g) lateral view; L. vriesianum - (h) dorsal view; and L. itabaiana - (i) dorsal view, (j) lateral view).

FIGURE 4. Leptagrion itabaiana at Serra of Itabaiana National Park, Sergipe, Brazil: (a) mating couple; (b) mature female; (c) teneral female; (d) bromeliad tank; and (e) mature male. Images: (a–d) ABSF, 2023; (e) JCS, 2023.