Pilielmis halia Hinton, 1971

Pinedo-Garcia, Raul Bismarck, Polizei, Thiago Tadeu Silva, Hamada, Neusa & Nascimento, Jeane Marcelle Cavalcante Do, 2024, Systematics of Pilielmis Hinton, 1971 (Coleoptera: Dryopoidea: Elmidae), Zootaxa 5421 (1), pp. 1-68 : 20-25

Pilielmis halia Hinton, 1971

( Figs 1 , 11–14 , 41C )

Pilielmis halia Hinton, 1971 a: 164 (original description); Passos et al. 2010 (taxonomic record).

Diagnosis. Body subparallel; general coloration light brown; antennae bicolor: antennomeres I and II yellow, antennomeres III–XI dark brown; elytra with two pairs of yellowish-brown marks (a pair near the humerus and a pair near the apex); metatrochanter with a gibbosity apically. Male: metatibia with an excavation; phallobase 1.5x longer than wide, lateral margins with a slight constriction medially; parameres reaching approximately 3/5 the length of the penis; penis 2.7x longer than wide, lateral margins with a slight constriction medially; basolateral process 3x longer than wide.

Male redescription. Length: mean = 1.64 mm; width: mean = 0.70 mm (n=5). Body subparallel ( Figs 11A , 41C ); general coloration light brown, with yellowish-brown marks on the elytra.

Head. Antennae bicolor: antennomeres I and II yellow and antennomeres III–XI dark brown ( Fig. 11D ). Labrum ( Fig. 12A ): suboval; anterolateral margins with long setae; dorsal surface with short setae along its entire length. Mandibles ( Fig. 12C, D ): lateral lobe slightly rounded; molar area with a groove at the base; posterolateral angle rounded; condyle 1.5x wider than long, rounded. Maxilla ( Fig. 12B ): cardo subtriangular, longer than wide; stipe subrectangular; palpomere IV as long as the basal ones combined, with a rounded apex; galea with apical section 2x longer than the basal one, with a truncated apex, with long, thin setae; lacinia subrectangular, 2x longer than wide, with long setae on inner lateral margin. Labium ( Fig. 12E ): postmentum subtriangular; prementum subrectangular, with base and apex convex, 6x wider than long, lateral margins rounded; ligula subrectangular, 3x wider than long, anterolateral angles rounded, surface with setae; gula 2x wider than long, lateral margins slightly sinuous, anterolateral angles rounded; labial palpomere III with rounded apex.

Thorax. Pronotum ( Fig. 11A ) wider (0.53 mm) than long (0.41 mm); lateral margins sinuous, with crenulations; anterolateral angles rounded; posterolateral angles acute; anterior region lighter than posterior region; with a pair of sinuous, weakly raised sublateral carinae; longitudinal impression on the disc shallow. Elytra ( Fig. 11A ) subparallel, 1.5x longer than wide (length = 1.11 mm; maximum width = 0.70 mm); apex rounded; humerus rounded, slightly projected; with two pairs of brown marks (a pair near the humerus and a pair near the apex). Scutellum cordiform. Metathoracic wings present ( Fig. 13D ). Hypomeron 4x longer than wide. Prosternum ( Fig. 11B ) 0.4x longer than wide; anterior margin concave; anterolateral angles sharp. Prosternal process ( Fig. 11B ) approximately as wide as long. Mesoventrite ( Fig. 11B ) wider (0.32 mm) than long (0.06 mm); cuticle similar to prosternum. Metaventrite ( Fig. 11B ) with discrimen conspicuous, reaching the anterior and posterior margins. Hind legs ( Fig. 11B ). Trochanter 2x longer than wide; metatrochanter with a gibbosity apically. Femora 3.6x longer than wide. Metatibia with an excavation on the apical half; with a tuft of long, thin setae. Tibiae 6x longer than wide. Apical tarsomere 1.5x longer than the basal ones combined. Claws large and slender, with a tooth near base.

Abdomen. Ventrites I–III without tomentum on disc; ventrite IV-V with golden setae ( Fig. 11B ). Tergite VIII ( Fig. 13B ) 1.4x wider than long, posterior margin rounded; surface covered by short setae, with spines and microspines. Sternite VIII ( Fig. 13C ) 2.6x wider than long; surface with short setae on disc, posterior margin with long, thin setae; anterior median projection 1.45x longer than the sternite body length. Segment IX ( Fig. 13E ) subtriangular; anterolateral margin with sensory pores and microespines; apical margin with short setae. Genitalia ( Fig. 13A ). Phallobase 1.5x longer than wide; approximately as long as the penis; lateral margins with a slight constriction medially. Parameres 2.1x longer than wide, reaching 3/5 the length of the penis; base wider than the apex; apex and lateral margins with sensory pores; lateral margins without crenulations. Penis 2.7x longer than wide; lateral margins with a slight constriction medially; apical region subtriangular with sensory micropores; basolateral process 3x longer than wide.

Female redescription. Externally similar to male, except by: metatibia without excavation and with a tuft of long, thin setae at apex. Length: mean = 1.66 mm; width: mean = 0.69 mm (n = 5). Tergite VIII ( Fig. 14B ) subtriangular, 1.3x wider than long; posterior margin rounded; surface with long setae (more abundant on anterior region) and short spines (more abundant on anterior 1/3). Sternite VIII ( Fig. 14C ) 1.67x wider than long; anterior median projection 1.6x longer than the sternite body length; posterior margin with long setae; surface with microspines. Ovipositor ( Fig. 14A ): valvifer dilated on posterior 1/3; 2x longer than the coxites; surface with sensory pores in the apical 1/3. Apical coxite 1.6x longer than wide, 1.7x longer than the basal one. Stylus slightly curved, measuring approximately 1/3 the length of the apical coxite.

Intraspecific variation. General body coloration darker in some specimens. Tergite VIII of the male varies slightly in number of pores and spines.

Comparative notes. Pilielmis halia resembles P. apama based on the body subparallel, antennae bicolor, anterior region of the pronotum lighter than the posterior region, and the humeral region of the elytra with a lighter mark. Pilielmis halia can be distinguished from P. apama by gibbosity in the apical region of the metatrochanter; males with an excavation on the metatibia; females with a tuft of long, thin setae at the apex of the metatibia and male genitalia with the following characteristics: phallobase 1.5x longer than wide, lateral margins with a slight constriction medially; penis 2.7x longer than wide, and basolateral process 3x longer than wide. In P. apama there is no gibbosity on the metatrochanter, and there is no excavation on the metatibia of males; also, the tuft of setae at the apex of the metatibia of females is absent; in the male genitalia, the phallobase is 2.3x longer than wide, without constrictions on the margins, the penis is 4.4x longer than wide and the basolateral process is 7.2x longer than wide.

Distribution: Brazil (Amazonas, Pará*, and Rondônia *) ( Fig. 1 ).

Material examined. Paratypes: BRAZIL. Amazonas : Manaus, ix.1937, H.E. Hinton (2♂ and 2♀ in NHMUK) . Additional material. BRAZIL, Amazonas: Manaus , 22.xi.2012, Polizei det. 2020 (alcohol) (1♂ in INPA) ; Presidente Figueiredo, Sossego da Pantera , Pantera stream, km 20 AM-240 , 04-05.vii.2000, 02°02′S, 59°50′′ W, 72m, Pes et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (approximately 1000 in INPA) . Pará: Paragominas , 04.vii.2011, 03°13′49.8′′ S, 46°55′19.9′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (4♀ in INPA) ; 20.VII.2011, 03°08′49.9′′S, 47°34′30.0′′W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (6 in INPA) ; 11.vii.2011, 02°48′49.6′′ S, 47°50′39.8′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1 ♂ in INPA) ; 26.vii.2011, 03°13′49.8′′ S, 46°55′19.9′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1♂ and 1♀ in INPA) ; 29.vii.2011, 03°42′59.7′′ S, 48°08′39.8′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1♂ in INPA) ; 20.ix.2018, 01°55′54.6′′ S, 60°59′50.5′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (13 in INPA) ; 09.vii.2011, 03°29′39.8′′ S, 47°58′49.8′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1♂ in INPA) ; 02.vii.2011, 03°27′19.8′′ S, 47°35′19.6′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (80% alcohol) (1♀ in INPA) ; 31.vii.2011, 03°13′49.8′′ S, 46°55′19.9′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020, (alcohol) (1♂ in INPA) . Rondônia: Machadinho do Oeste , São Paulo River, RO-205 , 24.viii.2016, 09°22′40.3′′, S 61°50′54.9′′ W, Hamada et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (70 in INPA) .

Figures

FIGURE 1. Map of SouthAmerica with detailed area indicating the distributional records forPilielmis Hinton, 1971 (Coleoptera: Elmidae).

FIGURE 11. Pilielmis halia Hinton, 1971 (Coleoptera: Elmidae). Adult, male, habitus. (A) Dorsal view. (B) Ventral view. (C) Lateral view. (D) Front view. Scale bars = 0.5 mm.

FIGURE 12. Pilielmis halia Hinton, 1971 (Coleoptera: Elmidae). Adult, mouthparts. (A) Labrum, dorsal view. (B) Maxilla, dorsal view. (C) Mandible, dorsal view. (D) Mandible, ventral view. (E) Labium, ventral view. Scale bars = 0.1 mm.

FIGURE 13. Pilielmis halia Hinton, 1971 (Coleoptera: Elmidae). Adult, male. (A) Genitalia, ventral view. (B) Tergite VIII, dorsal view. (C) Sternite VIII, dorsal view. (D) Metathoracic wing. (E) Segment IX, ventral view.

FIGURE 14. Pilielmis halia Hinton, 1971 (Coleoptera: Elmidae). Adult, female. (A) Ovipositor, ventral view. (B) Tergite VIII, dorsal view, with the central region highlighted. (C) Sternite VIII, dorsal view.

FIGURE 41. Paratypes of Pilielmis (Coleoptera: Elmidae). (A) Pilielmis murcia. (B) Pilielmis sara. (C) Pilielmis halia. (D) Pilielmis apama. (E) Pilielmis clita. (F) Pilielmis abdera. (G) Pilielmis shepardi. (A–F) Material housed at the NHMUK. (G) Material housed at MZSP. Scale bars = 0.5 mm.