Argidae (Malm and Nyman, 2015)

Malagon-Aldana, Leonardo A., Shinohara, Akihiko, Smith, David R. & Vilhelmsen, Lars, 2021, Comparative anatomy of the larvae of argid sawflies (Hymenoptera: Argidae): a phylogenetic approach, Organisms Diversity & Evolution (New York, N. Y.) 21 (2), pp. 361-392 : 383-388

Argidae internal relationships

Two main clades are recovered within Argidae , corresponding to the subfamilies Sterictiphorinae and Arginae as defined by Benson (1963) and corroborated by Malagón-Aldana et al. (2021). For the subfamily Arginae (SR = 60, k = 3), the following synapomorphies are identified: trochanter as long as wide [47:1] ( Fig. 13i ) and the surface of tergal sensilla with parallel longitudinal grooves [70:1] ( Fig. 15a, c, e, l ).

Clade A: the genera Antargidium + Scobina (SR = 73, k = 24–30) are retrieved as the sister group of the remaining genera ( Fig. 16m, n ); they share the following synapomorphies: abdominal legs tubular, 3× longer than wide [59:1] ( Fig. 16g ), and suprapedal lobes of abdomen independent [72:0] ( Fig. 16d, g ) (convergent with several pergids and tenthredinids). Malagón-Aldana et al. (2021) also retrieved these two genera in basal positions within Arginae in clades 1 and 2. However, they were not recovered as sister taxa. It was only possible to examine Antargidium larvae by consulting habitus photographs ( Fig. 16m ); therefore, many characters were impossible to score, including number of antennomeres and mouthparts. Some synapomorphies of Scobina ( Fig. 16n ) are the setae of the lacinia located in its mesal side and perpendicular to the galea [25:1] ( Fig. 12f ) (convergent with Cimbicidae ) and the presence of more than 16 setae [27:4] ( Fig. 12f ) (convergent with Cimbicidae , Perreyia and Philomastix ).

Clade B: Pampsilota + Arge s. lato (incl. Spinarge ) (SR = 74, k = 30) share the following synapomorphies: more than 11 anteromesal trichoid setae on the epipharynx [10:1; 11:1]; basal labial palpomere long, 1.5× longer than wide [31:2] ( Fig. 11b ); larvapods of the abdominal segments VII and VIII [55:0; 56:0] highly reduced or absent (convergent with some Sterictiphorinae and Pergids) and abdominal suprapedal lobes fused [72:1] ( Figs. 15g and 16f ). The cylindrical shape of the hind coxae, its base width subequal to its apex width [44:0] ( Fig. 13s ) supports the monophyly of the genus Arge s. lato (incl. Spinarge ) (SR = 65, k = 4–6). Two subclades can be recognized inside the Arge s. lato clade, one including Arge pullata + ( A. similis + ( A. pagana + A. quidia )) ( Fig. 1j ) (SR = 45, k = 27–30) and a second with A. berberidis + Spinarge spp. ( Fig. 1d ) (SR = 63, k = 1). The first subclade is supported by the presence of a mesal gland between the larvapods of the abdomen [58:1] ( Fig. 14d ), while a transverse band connecting the larvapods [60:1] ( Fig. 14a ) supports the second subclade. Both Boevé et al. (2018) and Malagón-Aldana et al. (2021) retrieved Spinarge within the genus Arge s. lato. Clade B is similar to clade 4 identified in Malagón-Aldana et al. (2021).

Sterictiphorinae (SR = 30, k = 4–6), is supported by the following synapomorphies: short third (apical) labial palpomere, shorter than half the length of the second labial palpomere [33:0] ( Fig. 11b ) and the basal labial palpomere subequal in size (length and width) to the second [32:0] ( Fig. 11a, d ). The Australian genus Trichorhachus ( Fig. 1e ) was retrieved as the sister group of the remaining Sterictiphorinae . Trichorhachus retains several plesiomorphic traits that distinguish it from the rest of Sterictiphorinae , and this may be the reason of the low support for the subfamily: antenna with two antennomeres [2:1] ( Fig. 8k ) (also in Diprionidae ); lacinia having trichoid setae with simple apex [26:0] ( Fig. 12l ) (present in Arginae , Pergidae and outgroups) and thoracic legs with six podomeres [41:0; 42:0] (like in Fig. 13p ). Malagón-Aldana et al. (2021) also retrieved Trichorhachus as sister to the rest of Sterictiphorinae .

Clade C: The remaining Sterictiphorinae (except for Trichorhachus ) (SR = 92, k = 24) are united by the multiple branched setae of the lacinia [26:1] ( Fig. 12g –i, m–o ) and epipharynx [11:2] ( Fig. 9d, e ) (reversed in Schizocerella , Fig. 12j ); having three maxillary palpomeres [16:0] ( Fig. 11k, n, p ) (reversed in Aproceros and Aprosthema , convergent with Perga ); anteromesal lobe of lacinia absent or reduced [28:0] (convergent with Scobina and Perreyia ); thoracic fore leg with four podomeres [41:2] ( Fig. 13a, c, g, k ) (reversed to five in Sterictiphora , Aproceros , and Aprosthema ); and the hind coxae subequal or longer than the remaining podomeres [45:1] ( Fig. 13q ) (convergent with Acordulecera ).

Clade D: All genera of this clade (SR = 51, k = 6) share the presence of postspiracular glands [61:1] ( Fig. 14g –i ). Atomacera ( Fig. 1f ) was retrieved as the sister group of the remaining genera; this genus is characterized by the absence of larvapods in the second and third abdominal segments [53:0; 54:0] and the presence of flask-shaped glands in all terga of the body ( Smith 1972). Sterictiphora + ( Aproceros + Aprosthema ) (SR = 92, k = 4) share a prespiracular gland present [34:1] ( Fig. 13l–o ), thoracic legs with five podomeres [41:1; 42:1] ( Fig. 13l, n ) (convergent in some pergids and tenthredinids), the presence of marginal fleshy conical protuberances [78:1] (also in Trichorhachus ) ( Fig. 14k, m ) and a pair of simple subanal lobes [80:1] ( Fig. 14k–o ) (convergent with Philomastix ). An autapomorphy for Sterictiphora (SR = 73, k = 18–30) is the cylindrical shape of the prespiracular gland [35:1] Fig. 13o ). Aproceros ( Fig. 1g ) + Aprosthema (SR = 78, k = 18–21) share the presence of deep sensillar fovea on the antenna [7:2] ( Fig. 8f ), the presence of irregular denticles on the inner surface of the mandibles [14:1] ( Fig. 10a, b, e ) and the flattened prespiracular gland ( Fig. 13m ) (reduced in Aproceros ). Aproceros + Aprosthema also retain the presence of four maxillary palpomeres [16:2], a plesiomorphic trait. This clade corresponds partly to clade 8 in Malagón-Aldana et al. (2021). However, in the present study Atomacera was recovered as the sister group of clade 8 ( Malagón-Aldana et al. 2021) and not as the sister of the remaining Neotropical genera (clade E).

Clade E: The genera that belong to this clade (SR = 52, k = 27–30) are united by the preapical maxillary palpomere being at least 1.5× as long the preceding palpomere [19:2] ( Fig. 11k, p–s ) (convergent with Aprosthema ); claws on pretarsus of fore legs absent [37:0] ( Fig. 13c, e ) (reversed in several genera) and suprapedal lobes fused [72:1] (like in Fig. 16f ) (also in Pampsilota + Arge ). This clade is similar to the clades 10 + 11 of Malagón-Aldana et al. (2021), comprising the Neotropical Sterictiphorinae where adult males have a furcate flagellum in the antenna and where most of the diversity of the subfamily is concentrated.

Clade F: (SR = 64, k = 3) Synapomorphies include the preapical maxillary palpomere length at least 2× its width [20:2] ( Fig. 11p, g ); second labial palpomere 1.5× longer than wide [32:2] ( Fig. 11c ); thoracic fore leg with coxal glands present [38:1] ( Fig. 13a–h ) (convergent with clades I and J). Neoptilia was recovered as the sister group of the remaining genera. Sericoceros + ( Dielocerus + Digelasinus ) (SR = 61, k = 1) share the deep mesal V-shaped emargination in the labrum [9:1] ( Fig. 9b ) (convergent with Cimbicidae and Spinarge ); coxal glands of thoracic fore legs with a pair of closing lips [39:1] ( Fig. 13a–e ) (convergent with Sphacophilus ) and large conic tubercles bearing the tergal sensilla [68:3] ( Fig. 15f ) (convergent with Pterygophorus + Perreyia ). The autapomorphy of Sericoceros is the presence of lateroventral non-eversible glands in the abdomen ( Fig. 16h, i ). Dielocerus + Digelasinus (SR = 99, k = 1–30) ( Fig. 1m, n ) share as synapomorphies the presence of three coxal glands on the fore legs [40:1] ( Fig. 13a, b ); basal labial palpomere at most 2/3× the length of the second [31:0] ( Fig. 11c ) (convergent with Pergagrapta ); larvapods absent in the second and seventh segments of the abdomen [53:0; 55:0]. This clade is congruent with clade 10 of Malagón-Aldana et al. (2021), the tribe Dielocerini of Benson (1938), and the subfamily Dielocerinae of Smith (1992). The position as sister group of the remaining Neotropical Sterictiphorinae (except for Atomacera ) was also retrieved by Malagón-Aldana et al. (2021) with IW analysis.

Clade G: This clade (SR <30) is united by having three podomeres in mid- and hind legs [42:3] ( Fig. 13r ) and two– three apical setae on the lacinia [27:0] ( Fig. 12j, m, n ) (reversed in Ptenos and Manaos ). This clade is similar to clade 11 of Malagón-Aldana et al. (2021), where the sister group of the remaining genera includes the genus Schizocerella ( Fig. 1k ), the latter having some plesiomorphies, e.g., the simple and flat setae of maxilla and epipharynx. Their internal clades ( Fig. 18h–j ) were well supported independently, but their relationships are uncertain.

Clade H: Didymia and Ptilia form a monophyletic clade, with Didymia ( Fig. 1l ) paraphyletic relative to Ptilia . This result was also retrieved by Malagón-Aldana et al. (2021) (clade 15a). Synapomorphies of the clade (SR = 77, k = 9) are the presence of long body tubular tubercles carrying long setae [68:4; 69:1] ( Fig. 15g, n ) on the body. They also are distinguishable from other genera in clade G by having pretarsal claws on the fore legs [37:1], a plesiomorphic character state.

Clade I: The genus Sphacophilus ( Fig. 1h ) is retrieved as monophyletic ( S. cellularis + S. apios ) (SR = 95, k = 1–30), contrary to what was found by Malagón-Aldana et al. (2021) using adult morphology (clades 12 and 13) and the same two species. The larval synapomorphies include the presence of scopa mandibularis conformed by simple trichoid seta [15:1] ( Fig. 10j, k ) and tenth abdominal tergum (T10) with a row or marginal posterior spurs [76:1] ( Figs. 14p and 16c ) (convergent with Atomacera ). Species of Sphacophilus also share having coxal glands of thoracic fore legs with a pair of closing lips [39:1] ( Fig. 13e ) convergently with Sericoceros , Dielocerus , and Digelasinus .

Clade J: Zynzus + ( Ptenos + Manaos ) (SR = 71, k = 1–2) ( Fig. 1c ) have the following synapomorphies: the presence of only one coxal gland in the fore legs with a simple opening without closing lips [39:0] ( Fig. 13s ) and a couple of small tubercles on the posteroventral area of the larvapods of the tenth abdominal segment [82:1]. This clade is similar to clade 15b identified by Malagón-Aldana et al. (2021).

Figures

Fig. 13 Larval thorax and legs, characters and states. a, b Dielocerus diasi. a Fore leg. b Fore coxal glands. c, d Sericoceros mexicanus. c Fore leg. d Fore coxal glands. e Sphacophilus apios fore leg. f Neoptilia malvacearum fore coxal glands. g, h Ptenos amazonicus. g Fore leg. h Fore coxal gland. i, j Scobina melanopyga. i Fore leg. j Fore pretarsus. k Didymia connurasae fore leg. l, m Aprosthema brunniventre. l Lateral prothorax and fore leg. m Prespiracular gland. n, o Sterictiphora serotina. n Lateral prothorax and fore leg. o Prespiracular gland. p, q Pampsilota dahomeyanus fore leg. q Pretarsus. r Ptenos amazonicus thorax, lateral view. s Arge berberidis hind leg. Abbreviations: cx, coxa; fm, femur; prt, pretarsus; sp, spiracle; tb, tibia; trc, trochanter; tr, tarsus

Fig. 15 Larval abdomen sensilla, characters and states. a Spinarge fulvicornis. b Arge berberidis. c Neodiprion lecontei (Diprionidae). d Sphacophilus apios. e Pampsilota dahomeyanus. f Dielocerus diasi. g Spinarge fulvicornis sublateral lobes (sllb). h Atomacera decepta. i Ptenos amazonicus. j Trichorhachus sp. k Cimbex sp. (Cimbicidae). l Scobina. m Schizocerella pilicornis. n Didymia connurasae. o Siobla sturmii (Tenthredinidae)

Fig. 16 Larval body, characters and states. a Sphacophilus apios thorax. b Monoctenus melliceps (Diprionidae) thoracic legs. c Sphacophilus apios T10 dorsal view. d Monoctenus melliceps (Diprionidae) posterior abdomen, lateral view. e Neodiprion lecontei (Diprionidae) larvapods. f Arge pullata abdomen, lateral view. g Scobina sp. Larvapods in lateral view. h, i Sericoceros mexicanus. h Lateroventral re- gion of abdomen. i Lateroventral gland. j Pterygophorus cinctus (Pergidae) abdomen posterior end. k Perga sp. (Pergidae) pretarsus. l Philomastix xanthophylax (Pergidae) abdomen posterior end. m Antargidium sp. Habitus. n Scobina sp. Habitus. Abbreviations: lvp, larvapod; S, abdominal sternum; sbp, subanal plate; splb, surpedal lobe; sp, spi- racle; T, abdominal tergum

Fig. 12 Maxilla, characters and states. a Siobla sturmii (Tenthredinidae). b Aproceros leucopoda. c Arge pullata. d Digelasinus diversipes. e Arge berberidis. f Scobina melanopyga. g Aprosthema brunniventre. h Dielocerus diasi. i Atomacera decepta. j Schizocerella pilicornis. k Pampsilota dahomeyanus. l Trichorhachus sp. m Didymia connurasae. n Sphacophilus apios. o Ptenos amazonicus. Abbreviations: ga, galea; lc, lacinia; mxp #, maxillary palpomere

Fig. 11 Maxillolabial complex, characters and states. a–d Labial palpus. a Ptenos amazonicus. b Spinarge fulvicornis. c Dielocerus diasi. d Schizocerella pilicornis. e–s Maxillary palpus. e Trichorhachus sp. f Waldheimia vitis (Tenthredinidae) apical palpomere. g Sphacophilus cellularis. h Acordulecera sp. (Pergidae). i Styracotechys dicelysma (Pergidae). j Perga sp. Apical (mxp 4) palpomere. k Schizocerella pilicornis. l, m Pterygophorus cinctus (Pergidae). l Apical palpomere. m Palpomere setae. n Atomacera decepta. o Arge pullata distal palpus. p Dielocerus diasi. q Scobina melanopyga. r Sterictiphora serotina. s Aprosthema brunniventre. Abbreviations: ga, galea; lc, lacinia; mxp #, maxillary palpomere; lbp #, labial palpomere

Fig. 1 Larva, lateral habitus. a Zenarge turneri. b Sericoceros sp. c Ptenos amazonicus. d Spinarge fulvicornis. e Trichorhachus sp. f Atomacera decepta. g Aproceros leucopoda. h Sphacophilus apios. i Neoptilia malvacearum. j Arge pullata. k Schizocerella pilicornis. l Didymia connurasae. m Digelasinus diversipes. n Dielocerus sp.

Fig. 14 Larval abdomen, characters and states. a–d Larvapods. Arge berberidis. b Scobina melanopyga. c Aproceros leucopoda. d Arge pullata. e Blasticotoma filiceti (Blasticotomidae) laterodorsal tergal processes. f Cimbex sp. (Cimbicidae) supraspiracular gland. g–i Postspiracular gland. Aproceros leucopoda. h Sterictiphora serotina. i Atomacera decepta. j Acordulecera sp. (Pergidae) sucker-like infraspiracular gland. k, l Aprosthema brunniventre. k Posterior end of abdomen lateral view. l Subanal lobe. m, n Aproceros leucopoda. m Posterior end of abdomen, dorsal view. n Subanal lobe. o Blasticotoma filiceti (Blasticotomidae) subanal lobe. Atomacera decepta posterior margin of T10. Abbreviations: lvp, larvapod; sp, spiracle; S, ab- dominal sternum; T, abdominal tergum

Fig. 8 Larval head, characters and states. a, b Styracotechys dicelysma (Pergidae). a Eye and antenna. b Crown-shaped seta of antenna. c Blasticotoma filiceti (Blasticotomidae). d, e Schizocerella pilicornis. d Antenna. e Placoidal sensilla of antenna. f Aprosthema brunniventre antenna and sensillar fovea. g Pterygophorus cinctus (Pergidae) sensillum basiconicum of antenna. h Sphacophilus cellularis antenna. i Pergagrapta polita (Pergidae) multi-spined setae. j Sterictiphora serotina eye and antenna. k Trichorhachus sp., antenna. l Arge pullata antenna. m Sericoceros mexicanus head, frontal view. n Trichorhachus sp., eye and antenna. o, p Cimbex sp. (Cimbicidae). o Labrum. p Head, posterior view. Abbreviations: ant, antenna; clp, clypeus; e, eye; fr, frons; lm, labrum

Fig. 9 Labrum and epipharynx, characters and states. a Arge pullata labrum. b Dielocerus diasi epipharynx. c Sterictiphora serotina epipharynx. d–k Epipharyngeal setae. d Atomacera decepta. e Aprosthema brunniventre. f Cimbex sp. (Cimbicidae). g Neodiprion lecontei. h Trichorhachus sp. i Pergagrapta polita (Pergidae). j Scobina melanopyga. k Pampsilota dahomeyanus. Abbreviations: clp, clypeus; epx, epipharynx, lm, labrum

Fig. 10 Mandibles, characters and states. a–c Aprosthema brunniventre. a Left mandible. b Right mandible. c Inner proximal denticles right mandible. d Dielocerus diasi. e, f Aproceros leucopoda. e Right mandible. f Left mandible. g, h Didymia connurasae. g Left mandible. h Right mandible. i Arge berberidis. j, k Sphacophilus cellularis. j Right mandible. k Scopa mandibularis. l, m Pergagrapta polita (Pergidae). l Left mandible. m Scopa mandibularis. n, o Perga sp. (Pergidae). n Right mandible. o Scopa mandibularis

Fig. 18 Preferred implied weight tree (k value = 15) with subfamily classification. Main clades are labelled with capital letter in circles (see “Discussion”). Symmetric resampling (SR) fre- quency values (in red) are the maximum value for that clade in all IW trees (k = 1–30). Black dots represent synapomorphies identi- fied by unambiguous optimiza- tion (WinClada)