Final instar larva of Franciscagrion longispinum Machado & Bedê, 2015 (Odonata Coenagrionidae), an endemic species from the springs of the São Francisco river Cezário, Rodrigo Roucourt Vilela, Diogo Silva Guillermo-Ferreira, Rhainer Zootaxa 2019 2019-08-20 4657 3 581 586 9X2PN Machado & Bede, 2015 Machado & Bede 2015 [644,1289,225,252] Insecta Coenagrionidae Franciscagrion GBIF Animalia Odonata 1 582 Arthropoda species longispinum   Figs. 1–6.   Material examined.  2 ♂♂and 1 ♀♀F0 exuvia ( Fig. 1a): BRAZIL, Serra da Canastra, São Francisco riverhistori- cal springs ( -20.2442, -46.4468),  08–iii–2018, Guillermo-Ferreiraleg., 2 ♂♂and 1 ♀♀F0 (reared in laboratory).   Head. Roughly trapezoidal, 1.88 as wide as long measured from the occipital bar to labrum convex cephalic lobes, with few punctuations, without setae. Ventral margin of the eyes at mandibles level. Antennae 7-jointed, third antennomere the longest. Distal half of antennomeres 1 and 2 and antennomeres 6 and 7 ochre, 3–5 yellow; length of antennomeres: 0.15 [0.16–0.13], 0.24 [0.26–0.22], 0.32 [0.33–0.32], 0.20 [0.19–0.20], 0.13 [0.13–0.14], 0.07[.06– 0.07], 0.06 [0.06–0.07]. Prementum 0.70 as wide as long. Dorsal surface of the prementum with 4–5 setae on each side, the inner one the smallest. Ligula prominent with crenulated distal margin. Labial palp with one tooth smaller than the movable hook. Five small teeth between movable hook and distal tooth. Five or six palpal setae with no spines at base. Among male individuals, one had five palpal setae, and four setae on each side of prementum, while the other male had six setae on labial palps and five on prementum. Mandibles with molar teeth but without molar crest, with the formula: L 1+2345 y ab (1<3<4<5<2)/ R 1+2345 y a (1<3<2<4<5) ( Fig. 4).  Thorax. Pronotum trapezoidal with a lobed lateral expansion at the posterior margin, bearing no setae. Wing pads yellow, extending up to S4. Legs yellow; femur crenulated with small setae.  Abdomen. Mostly pale, with dark spots all over the abdomen. Cerci conoidal; distal margin rounded in lateral view, pointed forwards; S8–9 with 2–3 small setae; ♂gonapophyses blunt; not reaching S10; ♀gonapophyses surpassing S10 (~ 1.36mm). Gills ( sensu Novelo-Gutiérrez 1992) laminar narrow at base, lanceolate with acuminate tips; granulated color pattern; median lamella shorter than lateral lamellae; tracheae ochraceous.   FIGURES 1–4.  Franciscagrion longispinum. 1a. F0 exuvia habitus; 2. antenna; 3. prementum: 3a. detail of labial palp, 3b. lateral row of setae; 4. right and left mandibles.  Measurements. Total length without appendages: 10.63 [10.03–11.47]. Total length of head: 1.43 [1.34–1.56]; max. width: 2.29 [2.16–2.26]. Prementum length: 1.47 [1.45–1.51]; max. width: 1.04 [1.01-1.05]. Total length of la- bial palp: 0.73; max. width: 0.24. Femur I: 0.99 [0.91–1.07]; II: 1.28 [1.17–1.45]; III: 1.67 [1.56–1.88]. Tibia I: 1.18 [1.16–1.23]; II: 1.35 [1.11–1.69]; III: 1.73 [1.54–1.95]. Inner wing pads: 2.85 [2.96–2.75]; external wing pads: 2.73 [2.66–2.86]. Medial caudal lamellae: 4.11 [4.21–4.02]; lateral caudal lamellae: 4.59 [3.92–5.15]. The ♀antenna was broken and was not added to the measurements.  Habitat and Ecology: The final instar larvae of  F. longispinumwere collected in the São Francisco river historical springs, on roots of the aquatic vegetation. The soil is permanently wet, defined as a Vereda wetland (a unique Neotropical savannah environment with typical hydrosoil and vegetation) ( Vilela et al. 2016). The species seems to be endemic and restricted to these springs.   FIGURES. 5a–c.  Franciscagrion longispinum. 5a. posterior view of F0 exuvia cerci, 5b. dorsal view of cercus, 5c. ventral view of F0 exuvia S9 and S10 ♂ gonapophyses.   FIGURE. 6.  Franciscagrion longispinum. Median and lateral lamellar of exuvia.  Remarks. Differential diagnosis.The characters discussed here were based on the identification key for Coenagrionoidae by Lozano et al. (2018, p. 475–494), and do not reflect phylogenetic relationships. Furthermore, based on preliminary data from a recent molecular analysis (Vilela et al. unpub. data),  Franciscagrionseems to be related to  Acanthagrion,  Homeoura,  Argentagrionand/or  Franciscobasis. However, since further analyses are needed to infer phylogenetic relationships, here we discuss morphologically similar genera.   TABLE 1.Larval traits of morphologically similar odonate species. The traits do not reflect phylogenetic relationships.    Species Cephalic lobe Ligula Premental Labial palp Labial palp distal  Lateral row  Wing pads  References  setae setae margin teeth    Franciscagrion  More than 20 Moderately  8–10  5–6  5  5–6 spines  Extending up to S4  This study    longispinum  spinules prominent    Homeoura More than 20 Convex and 6–8 5 7–8 No mention Reaching anterior third  Lozano et al. (2009)    chelifera spinules slightly crenulated of S4    Homeoura nepos 15 spinules, and Convex and finely 4–6 4 5–6 2–5 spines Reaching anterior margin  Tennessen (2009)  10–12 fine setae crenulated of S5    Homeoura More than 20 Convex and 7–8 3–4 8–9 3–5 spines Reaching mid length S4  Lozano et al.(2009)    lindneri spinules slightly crenulated    Argentagrion 12–15 spinules Not mentioned 8 5 3 2–4 spines Reaching S4 distal bor-  Bulla (1971)   ambiguum der or up to half of S5    Ischnura Poorly spinulose Prominent 8 Not mentioned Not mentioned 3 shorts Reaching to middle of S4  Geijskes (1941)   capreolus spines    Ischnura With few setae Prominent 8,10 or 12 5,6 or 7 5–6 7–8 setae Reaching anterior margin von Ellenrieder &    fluviatilis of S4 Muzón (2003)    Ischnura ramburii Small spines Prominent 10 5 Not mentioned 5 short spines Reaching S4 distal bor-  Geijskes (1941)  der or shorter The larvae of  Franciscagriondo not present the lateral carina in the abdomen, which is present in the larvae of  Ischnuraand  Argentagrion.  Argentagrionlarvae are also smaller (~ 6mm) than  Franciscagrion(~ 10mm).  Homeouralarvae do not have unique diagnostic characters, however, they can be distinguished from  Franciscagrionby presenting the medial margin of the labial palp crenulated; while  Franciscagrionpresents smooth medial margins of the labial palp. The larvae of  Acanthagrionand  Franciscagrioncan be differentiated by the size of the caudal lamellae, which are as long as the abdomen in  Acanthagrion, while in  Franciscagrion, the abdomen is 1.50 times longer than the mean length of the caudal lamellae. For more comparisons about larval traits, please see Table 1. 2848417301 2018-03-08 Guillermo-Ferreira Brazil -20.2442 Serra da Canastra 7 -46.4468 Sao Francisco river 1 582 3 1 2