Description of the larvae of three species of Laccophilus Leach and comments on the phylogenetic relationships of the Laccophilinae (Coleoptera: Dytiscidae) Author Michat, Mariano C. text Zootaxa 2008 1922 47 61 journal article 10.5281/zenodo.184741 abd27f14-0192-4987-bddf-6dccb8d6700d 1175-5326 184741 Laccophilus obliquatus Régimbart ( Figs. 1–3 , 5 , 8–9, 11, 13–14, 17–20 , 22, 24–26, 28–30 , Tables 1–2 ) Distribution . This species is known from Brazil , Paraguay , Uruguay , and within Argentina from Buenos Aires, Chaco, Entre Ríos, Misiones, Santa Fe and Tucumán Provinces ( Trémouilles 1998 ; Benetti et al. 2003 ). Source of material . Seven specimens of instar I, three of instar II and four of instar III were used for the descriptions. Larvae were collected in association with adults at the following locality: Argentina , Buenos Aires City, 14/ 30-XI-2001 , large temporary rain pool about 50 m long, with clear water, soil bottom and abundant vegetation (mainly grasses). FIGURES 8–18. Laccophilus , first-instar larva. 8–9, L. obliquatus , antenna: 8, dorsal aspect; 9, ventral aspect. 10, L. testudo , antenna, ventral aspect. 11, L. obliquatus , mandible, dorsal aspect. 12, L. paraguensis , mandible, ventral aspect. 13–14, L. obliquatus , maxilla: 13, dorsal aspect; 14, ventral aspect. 15, L. paraguensis , maxilla, ventral aspect. 16, L. testudo , maxilla, ventral aspect. 17–18, L. obliquatus , labio: 8, dorsal aspect; 9, ventral aspect. Scale bars = 0.04 mm. FIGURES 19–21. Laccophilus , first-instar larva. 19–20, L. obliquatus , metathoracic leg: 19, anterior aspect; 20, posterior aspect. 21, L. testudo , metathoracic leg, posterior aspect. Scale bars = 0.10 mm. Diagnosis . Color of cephalic capsule as in Figs. 5 (instar I) and 26 (instar III). Head width = 0.33–0.36 mm (instar I), 0.50–0.52 mm (instar II) and 0.77–0.79 mm (instar III) ( Table 1 ). Cephalic capsule subtriangular, without neck constriction (instar I) ( Fig. 3 ). Distal third of ventrointernal margin of MN with denticles (instar I). Legs less densely covered with minute slender spinulae (instar I). Seta AN3 located dorsally (instar I) ( Fig. 8 ). Setae MX 5 and MX 6 strongly curved posteriorly (instar I) ( Fig. 14 ). Seta FE5 short on meso- and metaFE (instar I) ( Fig. 20 ). Seta AB11 short (instar I) ( Fig. 22 ). Cephalic capsule with two spine-like secondary setae on each lateral margin of PA and one spine-like secondary seta on each side of ventral surface of PA (instars II-III) ( Fig. 26 ). Meso- and metatergite with one spine-like secondary seta on each side and without spine-like secondary setae on central portion (instar II). U with few hair-like secondary setae (instar II). FR without reticulation (instar III). A3 somewhat longer that A1 (instar III) ( Table 1 ). CO with a smaller number of secondary setae (instar III) ( Table 2 ). Measurements and ratios that characterize body shape are shown in Table 1 . Secondary leg setation is detailed in Table 2 and Figs. 28–29 . Description of color . Instar I. Dorsal surface of cephalic capsule light brown except for anterolateral angles testaceous, one large, rounded, testaceous macula centrally, one small testaceous macula medially posterior to spatulate setae, and one relatively large testaceous macula laterally posterior to each ocular area ( Fig. 5 ); ventral surface of cephalic capsule testaceous to light brown; head appendages testaceous to light brown, MN slightly darker; thoracic and abdominal sclerites light brown; membranous parts white to testaceous; legs testaceous to light brown; U light brown. Instar II . As instar I except: anterolateral angles of cephalic capsule light brown; small testaceous macula posterior to spatulate setae absent; basal area near occipital foramen testaceous; light brown areas on dorsal surface of cephalic capsule with brown maculae; anterior portion of protergite testaceous. Instar III . As instar II except: thoracic tergites testaceous to light brown with brown maculae.