taxonID	type	description	language	source
03E687B3FF97FFF6FE47FAA1BE9A8582.taxon	description	First instar larva (Figs 7, 11 – 22). Diagnosis. Head capsule suboval; frontal lines inversely bell-shaped, merging before occipital foramen, coronal line present, extremely short (Fig. 11); clypeolabrum asymmetrical, nasale slightly asymmetrical, shorter than lateral lobes (Figs 11, 13); lateral lobes of epistome asymmetrical, projecting farther than nasale, left lobe larger than right lobe, slightly serrated on inner margin (Fig. 11); posterior tentorial grooves close to midline, before basal half (Fig. 12). Cervical sclerites present (Fig. 11). Antenna short (Fig. 14), basal antennomere the longest, sensory appendage 0.55 – 0.63 × as long as third antennomere. Mandibles asymmetrical (Figs 15, 16), right one slightly smaller (Fig. 16), with a stout inner tooth serrated distally; left mandible with two sharp inner teeth on basal half, covered by a short pubescence (Fig. 15); both mandibles serrated on distal inner margin. Maxilla (Figs 17, 18) with large stipes, longer than palpus, inner margin with dense pubescence (formed by fine spinulae) on inner and outer margins; first palpomere the longest, wider than long, dorsally pubescent; second and third palpomeres shorter than both first and fourth palpomeres. Labium with submentum completely fused to head capsule, lines of fusion not evident, mentum slightly wider than prementum (Fig. 12); basal palpomere the shortest; ligula reduced (Figs 19, 20); dorsally with sharp cuticular spines on membrane between mentum and prementum, and between prementum and first palpomere (Fig. 19). Hypopharynx asymmetrical, membranous and pubescent, developed as a lobe on left side (Fig. 9, third instar larva). Pronotal plate large, covering most of pronotum; those of meso- and metathorax shorter. First abdominal tergum membranous (see Fig. 1, third instar larva); abdominal segments one to seven with two dorsal rows of spines; dorsal plate on abdominal segment eight large, suboval; abdominal segments one to eight with two horizontal rows of strong spines on ventral face, laterally ending in lobed projections or “ prolegs ” which bear larger spines (Figs 2, 3,10 show the character in third instar larva); legs short, five-segmented (Figs 3, 21, 22). Chaetotaxy: Two innermost seta of gFR 1 short and stout, placed on small lobe (Figs 7, 13); PA 26 + 27 + 28 not closely aggregated (Fig. 12); seta AN 9 absent (Fig. 14); inner margin of stipes with row of additional unifid setae (gMX 2) (Fig. 17); pore LA 8 located in a distal position (Fig. 19); with additional seta near LA 10 (Fig. 19); sensilla LA 11 and LA 12 absent (Figs 19, 20). The illustrated specimen (Fig. 11) has an extra seta (PA?) near PA 13, this seta is not present on the left side nor in any other examined specimens, therefore it is not considered an additional seta. Primary chaetotaxy (Figs 11 – 22). Head capsule (Figs 11 – 13). Frontale with 30 sensilla: two very short setae on basal third, close to frontal lines (FR 1); two pores (FR 2) and two minute setae (FR 3) close to midline on distal half; five pairs of setae (FR 5 rather long, FR 6 long, FR 7 short, FR 9 rather long, FR 10 long) and two pairs of pores (FR 4, FR 14) close to base of each antenna; distal area of frontale with two pairs of setae (FR 8 long, FR 12 short) and three pairs of pores (FR 11, FR 13, FR 15); nasale with six short setae (gFR 1), middle two stouter and placed on a small lobe (Figs 7, 13), each epistomal lobe with two short anterior setae (gFR 2). Each parietale with 31 sensilla. Dorsal surface with a basal longitudinal row of four very short setae (PA 1, PA 2, PA 4, PA 5) and one pore (PA 3); one subbasal pore (PA 6) close to frontal lines; three long setae (PA 12, PA 13, PA 14) and one very short seta (PA 7) arranged in a transverse row posterior to midlength; three long setae ◄ Figs 1 – 10. 1 – 3 – habitus of the third instar larva of Dactylosternum cacti (LeConte, 1855) (1 – dorsal view; 2 – ventral view; 3 – lateroventral view). 4 – 6 – habitus of the third instar larva of Phaenonotum exstriatum (Say, 1835) (4 – dorsal view; 5 – ventral view; 6 – lateral view). 7 – middle setae of gFR 1 of Dactylosternum cacti; 8 – branched setae on head capsule of Phaenonotum exstriatum (second instar larva); 9 – labium with hypopharyngeal lobe of D. cacti (third instar larva, ventral view); 10 – rows of spines and ‘ proleg’ of D. cacti (third instar larva, ventral view). Scale bars: Figs 1 – 6 = 1 mm, Fig. 9 = 0.05 mm. (PA 8, PA 11 and PA 14) and two pores (PA 10, PA 15) in a transverse row in the area surrounding the stemmata; three setae (PA 9 long, PA 20 short, PA 21 long) and one pore (PA 19) on anterolateral corner of head capsule. Ventral surface with three pores (PA 23, PA 24, PA 25) and one rather long seta (PA 22) on anterolateral corner, close to mandibular acetabulum; two long setae (PA 16, PA 18) and two pores (PA 17, PA 30) along outer margin; one short seta (PA 26), one long seta (PA 28), and two pores (PA 27, PA 29) forming a longitudinal row closer to midline. Antenna (Fig. 14). A 1 bare, with five pores, three dorsal on distal half (AN 1 at midlength on outer margin, AN 2 close to midline, AN 4 distally on inner margin) and two ventral, on distal margin (AN 3, AN 5). A 2 with one dorsal pore (AN 6) on distal third, two short subapical setae (AN 7 on outer margin, AN 8 close to midline) close to base of SE 1, and two subapical setae on inner margin (AN 10 long, AN 11 short); AN 9 absent. A 3 with a group of at least three short setae, three long setae and one pore (gAN). Mandibles (Figs 15 – 16). Both mandibles with six sensilla: one short seta on outer margin at midlength (MN 1), one minute seta on outer margin at distal quarter (MN 5), three dorsal pores at level of inner retinaculum (MN 2, MN 3, MN 4); MN 6 minute, difficult to see, located subapically close to inner margin. Maxilla (Figs 17 – 18). Cardo with one rather long seta (MX 1). Stipes with a row of ca. 16 – 17 stout and short setae along inner margin (gMX 2), those at midlength closely aggregated, basal seta of that row likely homologous to MX 7; ventral face of stipes with three pores, one at midlength (MX 2), one subapical close to inner margin (MX 3) and one subapical on outer margin (MX 4); two long setae distal to pore MX 4 (MX 5, MX 6). MP 1 dorsally with one subbasal spiniform seta (MX 16) on inner margin and one pore close to base of appendage (MX 17); ventrally with two long subapical setae (MX 13, MX 14) and two pores (MX 12 on outer margin, MX 15 at base of appendage); inner appendage with three long setae and one short sensillum (gAPP). MP 2 with two pores, one ventral and apical (MX 18) and one dorsal on membrane connecting with MP 3 (MX 19); subbasal minute seta present on outer margin (MX 27). MP 3 with two long setae and two pores, one seta dorsal, on outer margin (MX 23), the other ventral on mesal margin (MX 21); both pores on ventral surface, one close to seta MX 21 (MX 22), the other apical, close to outer margin (MX 20). MP 4 with one long basal seta dorsally (MX 24) on inner margin and two subapical pores on outer margin (MX 25 digitiform and dorsal, MX 26 ventral); a group of at least six or seven short setae constitute gMX. Labium (Figs 12, 19 – 20). Submentum with two pairs of setae on anterior margin (Fig. 12), one long (LA 1), the other minute (LA 2). Mentum with two rather long setae (LA 3) and two pores (LA 4) on ventral surface close to anterolateral angle, LA 3 anterior to LA 4. Prementum ventrally with two pairs of setae (LA 5 minute and basal, LA 6 long and subapical) and one pair of subapical pores (LA 7); dorsally with one apical pair of pores (LA 8), one apical pair of minute seta-like sensilla (LA 9) and two pairs of stout setae distally on membrane connecting with labial palpi, inner pair very long (LA 10), outer pair additional (LA ■). Sensilla associated with ligula absent (LA 11, LA 12). LP 1 with one minute seta (LA 13, ventral) and one distal pore (LA 14, dorsal) on membrane connecting with LP 2; LP 2 with one subapical pore on outer face (LA 15) and a group of at least five setae and two pores in the apex constitute (gLA), four setae short, one rather long. Legs (Figs 21 – 22). The number and position of pores are the same in pro-, meso-, and metathoracic legs. Coxa with 3 pores (1 anterodorsal, 2 posterior) and 17 setae (12 anterior, 5 posterior); trochanter with 8 pores (5 anterior, 3 posterior) and 6 setae (3 anterior, 3 posterior); femur with 2 pores (1 anterior, 1 posterior) and 7 setae (5 anterior, 2 posterior); tibiotarsus with 1 anterior pore and 16 setae (10 anterior, 6 posterior); pretarsus with two subbasal setae (1 anterior, 1 posterior). Morphometry. See Table 2. Second instar larva. Chaetotaxy. More similar to the third instar than to the first. Head capsule. Frontale and parietale bearing several small secondary sensilla; middle setae of gFR 1 not stout, lobe absent. Antenna. Without secondary sensilla; sensory appendage proportionally longer than in third instar. Mandible. With several minute secondary sensilla on outer face. Maxilla. With two or three minute secondary setae on ventral face of stipes, gMX 2 with 17 – 18 setae, distal ones slightly longer and narrower than basal ones. Labium. Without secondary sensilla. Number and distribution of pores and setae in legs similar to first instar larva. Morphometry. See Table 2. Third instar larva (Figs 23 – 32). Chaetotaxy. Head capsule (Figs 23 – 25). Frontale with eight to 10 secondary sensilla arranged in a row subparallel to each frontal line starting behind FR 1 and extending slightly past pore FR 2; a minute secondary seta present in some specimens between FR 3 and FR 6 (Fig. 25); middle setae of gFR 1 not stout, lobe absent. Each parietale with 15 to 17 short secondary setae and one or two small secondary pores on dorsal surface; ventrally with 17 to 18 short or minute secondary setae and one secondary pore in some specimens. Posterior tentorial grooves at midlength, slightly more distally placed than in first instar larvae. Antenna (Fig. 26) without secondary sensilla, sensory appendage shorter, 0.42 – 0.50 × as long as third antennomere. Mandibles (Figs 27 – 28). Each mandible with eight to nine short secondary setae, most of them on basal outer face. Maxilla (Figs 29 – 30). Stipes with three secondary setae on ventral face, one very short close to outer margin, one minute at midlength between MX 3 and MX 4, and one short on outer margin close to MX 5 and MX 6; inner row of setae on stipes with ca. 18 – 19 setae (gMX 2), distal ones longer and more slender, basal one slightly apart from others, probably homologous to MX 7. Labium (Figs 31 – 32) without secondary sensilla. Number and distribution of pores and setae in legs similar to first instar larva. Morphometry. See Table 2.	en	Archangelsky, Miguel, Rodriguez, Georgina, Torres, Patricia L. M., Liesa, Ciemep-Conicet, Dbbe, FCEyN (2016): Primary chaetotaxy and larval morphometry of Phaenonotum exstriatum and Dactylosternum cacti (Coleoptera: Hydrophilidae). Acta Entomologica Musei Nationalis Pragae 56 (1): 167-193, DOI: 10.5281/zenodo.5757567
03E687B3FF9BFFEFFE59FE7ABEF486AA.taxon	description	First instar larva (Figs 33 – 43). Diagnosis. Head capsule subquadrate to slightly suboval; frontal lines inversely bell-shaped, merging just before occipital foramen, coronal line present, extremely short (Fig. 33); clypeolabrum symmetrical, bearing three short teeth, middle one projecting farther than lateral ones (Figs 33, 35); lateral lobes of epistome almost symmetrical, projecting farther than nasale, slightly serrated on inner margin, with a sharp short spine on outer angle pointing mediad (Figs 33, 35); posterior tentorial grooves close to midline, past midlength, just behind submentum (Fig. 34). Cervical sclerites present, narrow and elongate (Fig. 33). Antenna short (Fig 36), basal antennomere the longest, sensory appendage as long as third antennomere. Mandibles symmetrical (Fig. 37), with two inner teeth and inner border serrated. Maxilla (Figs 38, 39) with large stipes, longer than palpus, with strong cuticular spines on outer face dorsally and an apical stout and sharp projection on inner margin; first and fourth palpomeres subequal in length, longer than second and third. Labium with submentum fused to head capsule, subtriangular; mentum slightly wider than prementum, with strong cuticular spines dorsally (Fig. 40); basal palpomere the shortest, membranous area at base of both palpomeres with sharp cuticular spines; ligula twice as long as first palpomere (Figs 40, 41). Pronotal plate large, covering most of pronotum; those of meso- and metathorax shorter (see Figs 4, 6, third instar larva). First abdominal segment dorsally with a pair of narrow, poorly sclerotized sclerites (Figs 4, 6, third instar larva); dorsal plate on abdominal segment eight subdivided (Fig. 4, third instar larva); abdominal segments two to seven ventrally not strongly lobed (Figs 5, 6, third instar larva), with two rows of short spines but not “ prolegs ”; legs short, five-segmented (Figs 42, 43). Chaetotaxy. Setae PA 8, PA 9, PA 14, PA 16, PA 21, PA 28, FR 6, FR 10, FR 8 and AN 10 branched (as in Fig 8); setae PA 7, PA 12, PA 13 closely aggregated; seta AN 9 absent; inner margin of stipes with row of additional bifid setae (gMX 2). Primary chaetotaxy (Figs 33 – 43). Head capsule (Figs 33 – 35). Frontale with 30 sensilla: two short setae on basal third, close to frontal lines (FR 1); two pores (FR 2) and two minute setae (FR 3) closer to midline on distal half; five pairs of setae (FR 5 short, FR 6 short and branched, FR 7 short, FR 9 short, FR 10 short and branched) and two pairs of pores (FR 4, FR 14) close to base of each antenna; distal area of frontale with two pairs of setae (FR 8 short and branched, FR 12 very short) and three pairs of pores (FR 11, FR 13, FR 15); nasale with six short and stout setae (gFR 1), each epistomal lobe with two anterior setae pointing mediad (gFR 2). Each parietale with 30 sensilla. Dorsal surface: with a basal longitudinal row of four very short setae (PA 1, PA 2, PA 4, PA 5) and one pore (PA 3); one subbasal pore (PA 6) close to frontal line; three closely aggregated long setae at midlength (PA 7, PA 12, PA 13); two pores (PA 10, PA 15) and two setae at distal third (PA 11 short, PA 14 rather long and branched) in the area surrounding the stemmata; one short branched seta close to frontal line behind antennal socket (PA 8) and one pore (PA 19) and three setae on anterolateral corner of head capsule (PA 9 rather long and branched, PA 20 long, and PA 21 rather long and branched). Ventral surface with three pores (PA 23, PA 24, PA 25) and one long seta (PA 22) on anterolateral corner, close to mandibular acetabulum; two pores (PA 17, PA 30) and two setae (PA 16 rather long and branched, PA 18 long) along outer margin; two pores (PA 27, PA 29) and two setae (PA 26 short, PA 28 rather long and branched) forming a longitudinal row closer to midline, PA 26, PA 27 and PA 28 very close together at about midlength, PA 29 at basal fourth. Antenna (Fig. 36). A 1 bare, with five pores, four on dorsal face (AN 1 basal on outer margin, AN 2 at midlength, AN 3 distally on outer margin, AN 4 distally on inner margin) and one on ventral face (AN 5 on inner distal margin). A 2 with one dorsal pore (AN 6) on distal half, two subapical setae (AN 7 short, AN 8 minute) on outer margin close to base of SE 1, and two subapical setae on inner margin (AN 10 long and branched, AN 11 short); AN 9 absent. A 3 with a group of at least six setae (two long, one short and three very short). Mandible (Fig. 37) with six sensilla, one short seta on outer face at basal third (MN 1), one minute seta on outer margin at distal quarter (MN 5), and three dorsal pores at level of distal retinaculum (MN 2, MN 3, MN 4). MN 6 minute, difficult to see, located subapically close to inner margin. Maxilla (Figs 38 – 39). Cardo with one rather long seta (MX 1). Stipes with a row of 14 short and stout setae, distal 13 (gMX 2) bearing a subapical spine and separated by a longer distance, becoming closer to each other basally, basal seta simple (homologous to MX 7) slightly more distant from others; apical outer face of stipes with two long setae (MX 6 dorsal, MX 5 ventral) and one pore (MX 4 ventral); ventral face with two pores (MX 2 at midlength closer to outer margin, MX 3 more distally and closer to inner margin). MP 1 dorsally with one subbasal rather long seta (MX 16) on inner margin and one pore close to base of appendage (MX 17); ventrally with two long subapical setae (MX 13, MX 14) and two pores (MX 12 on outer margin, MX 15 at base of appendage); inner appendage with at least three sensoria (gAPP, one rather long seta, one short branched seta, one short stout seta). MP 2 with two pores, one dorsal and apical on inner margin (MX 19) and one ventral on outer margin (MX 18), and one minute seta basally on outer margin (MX 27). MP 3 with two rather long setae and two pores, one seta dorsal, on outer margin (MX 23), the other ventral on inner margin (MX 21); both pores on ventral surface, one close to outer margin (MX 20) the other (MX 22) close to seta MX 21. MP 4 with one rather long basal seta dorsally on inner margin (MX 24) and two subapical pores on outer margin (MX 25 digitiform and dorsal, MX 26 ventral); a group of six or seven short setae constitute gMX. Labium (Figs 34, 40 – 41). Submentum with two pairs of setae on anterior margin (Fig. 34), one long (LA 1), the other minute (LA 2). Mentum with two long setae (LA 3) and two pores (LA 4) on ventral surface, LA 4 close to anterior margin, anterior to LA 3. Prementum ventrally with two pairs of setae (LA 5 minute and basal, LA 6 long at midlength) and one pair of subapical pores (LA 7); dorsally with one basal pair of pores (LA 8) and one pair of minute seta-like sensilla (LA 9) on membrane connecting with labial palpi and ligula. Ligula with one pair of long setae at the base (LA 10) and two pairs of sensilla (LA 12 cone-like, apical on dorsal face and LA 11 pore-like, at midlength on ventral face). LP 1 with one minute seta (LA 13, ventral) and one distal pore (LA 14 dorsal) on membrane connecting with LP 2; LP 2 with one subapical pore on outer face (LA 15) and a group of at least nine setae at the apex constitute gLA, three setae minute, four setae short, one rather long and one long seta. Legs (Figs 42 – 43). The number and position of pores are the same in pro-, meso-, and metathoracic legs. Coxa with 2 pores (1 anterodorsal, 1 posterior) and 14 setae (12 anterior, 2 posterior); trochanter with 8 pores (5 anterior, 3 posterior) and 9 setae (5 anterior, 4 posterior); femur with 2 pores (1 anterior, 1 posterior) and 10 setae (5 anterior, 5 posterior); tibiotarsus with 2 pores (1 anterior, 1 posterior) and 17 setae (8 anterior, 9 posterior); pretarsus with two setae (1 anterior, 1 posterior). Morphometry. See Table 2. Second instar larva. Chaetotaxy more similar to the third instar than to the first. Head capsule. Frontale lacking secondary setae; parietale bearing four small secondary sensilla in similar positions than those of third instar (except for the one close to the frontal line that is absent). Antenna. Without secondary sensilla. Mandible with five or six short secondary sensilla on outer face. Maxilla. Stipes with 12 – 13 stout secondary setae on dorsal surface and one branched ventral secondary seta close to MX 4 and MX 6; gMX 2 with ca. 13 setae. Labium. Mentum with one pair of long secondary setae dorsally on distal half. Number and distribution of pores and setae in legs similar to first instar larva. Morphometry. See Table 2. Third instar larva (Figs 44 – 52). Lateral lobes of epistome projecting slightly farther than nasale, slightly serrated on inner margin but with spine on outer angle much smaller. Chaetotaxy. Head capsule (Figs 44 – 46). Frontale without secondary sensilla. Parietale with five secondary sensilla, one ventral seta close to PA 18, one dorsal pore near PA 19 and two dorsal setae, one close to PA 8, the other close to frontal line, near pore FR 2; PA 21 apparently simple in examined specimens (branched in first and second instars). Antenna (Fig. 47) without secondary sensilla. Mandible (Fig. 48) with four short basal secondary setae close to outer face, and three or four minute secondary setae close to MN 1. Maxilla (Figs 49 – 50). Stipes with ca. 17 stout secondary setae on dorsal surface and one branched ventral secondary seta between pore MX 4 and seta MX 6; gMX 2 with 13 – 14 setae. Labium (Figs 51 – 52). Mentum with one pair of long secondary setae dorsally on distal half. Number and distribution of pores and setae in legs similar to first instar larva. Morphometry. See Table 2.	en	Archangelsky, Miguel, Rodriguez, Georgina, Torres, Patricia L. M., Liesa, Ciemep-Conicet, Dbbe, FCEyN (2016): Primary chaetotaxy and larval morphometry of Phaenonotum exstriatum and Dactylosternum cacti (Coleoptera: Hydrophilidae). Acta Entomologica Musei Nationalis Pragae 56 (1): 167-193, DOI: 10.5281/zenodo.5757567
