Pilielmis sara 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 : 14-19

Pilielmis sara Hinton, 1971

( Figs 1 , 7–10 , 46B)

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

Diagnosis. Body subparallel; general coloration yellowish-brown; antennae bicolor: antennomeres I and II yellow, antennomeres III–XI dark brown; pronotum with a pair of black marks on the posterior half; elytra with black marks (a mark on the elytral suture near the scutellum, a pair in the middle of the elytra, and a pair near the apex); metaventrite with a short carina at the base of the discrimen. Male with phallobase 2.2x longer than wide; parameres reaching 3/5 the length of the penis, with crenulate lateral margins; penis 2.5x longer than wide, lateral margins strongly constricted; basolateral process 2x longer than wide.

Male redescription. Length: mean = 1.79 mm; width: mean = 0.71 mm (n = 3). Body subparallel ( Figs 7A , 41B ); general coloration yellowish-brown, with black marks on the pronotum and elytra.

Head. Antennae bicolor: antennomeres I and II yellow, antennomeres III–XI dark brown ( Fig. 7D ). Labrum ( Fig. 8A ): suboval; anterolateral margins with long setae; dorsal surface with short setae sparsely distributed along its entire length. Mandible ( Fig. 8C, D ): lateral lobe rounded, slightly projected; molar area with a groove at the base; posterolateral angle strongly rounded; condyle wider than long, subtriangular. Maxilla ( Fig. 8B ): cardo longer than wide; stipe subsquare; palpomere IV elongated, 2x longer than the previous one, with a rounded apex; galea with apical section suboval, 3x longer than the basal one, lateral margin with rounded apex, with long, thin setae; lacinia subrectangular, 2x longer than wide, with long setae on inner lateral margin. Labium ( Fig. 8E ): postmentum subtriangular; prementum subrectangular, with base and apex convex, 5x wider than long; ligula subrectangular, 3x wider than long, anterolateral region with short spines, ventral surface with two transverse rows of spines on disc; labial palpomere III with rounded apex.

Thorax. Pronotum ( Fig. 7A ) wider (0.56 mm) than long (0.44 mm); lateral margins sinuous, with crenulations; anterolateral angles rounded; posterolateral angles acute; anterior region narrower than the posterior region; with a pair of black marks on posterior half; with a pair of sinuous, weakly raised sublateral carinae; longitudinal impression on the disc shallow. Elytra ( Fig. 7A ) 1.8x longer than wide (length = 1.24 mm; maximum width = 0.73 mm); with apex rounded; humerus and the elytral suture darker; with black marks (a mark on the elytral suture near scutellum, a pair in the middle of the elytra, and a pair near the apex). Scutellum subtriangular. Metathoracic wings present ( Fig. 9D ). Hypomeron 4x longer than wide. Prosternum ( Fig. 7B ) 0.4x longer than wide; anterior margin concave; anterolateral angles acute. Prosternal process ( Fig. 7B ) longer than wide; disc flat. Mesoventrite ( Fig. 7B ) wider (0.25 mm) than long (0.16 mm) with cavity; cuticle similar to prosternum. Metaventrite ( Fig. 7B ) wider (0.28 mm) than long (0.09 mm) with a short carina in the base of discrimen; disc flat; surface with short setae; lateral margins covered by tomentum. Hind legs ( Fig. 7B ). Trochanter 2x longer than wide. Femora 4.2x longer than wide. Tibiae 5.2x longer than wide. Apical tarsomere 1.3x longer than the basal ones combined. Claws large and slender, with a tooth near base.

Abdomen. Ventrites I–IV without tomentum on disc; ventrite V with short golden setae at the apex ( Fig. 7B ). Tergite VIII ( Fig. 9B ) wider than long, posterior margin rounded; surface with thin setae, spines and microspines. Sternite VIII ( Fig. 9C ) 2.7x wider than long; surface with setae and microspines (more abundant on the posteromedial portion); with long setae near the apex; anterior median projection 1.6x longer than the sternite body length. Segment IX ( Fig. 9E ) subtriangular, with rounded apex; with setae and microspines on the apical region. Genitalia ( Fig. 9A ). Phallobase 2.2x longer than wide; 1.5x longer than the penis. Parameres reaching 3/5 the length of penis; base wider than apex; apex rounded; lateral margins crenulate; surface with sensory pores. Penis 2.5x longer than wide; apical region subtriangular; lateral margins sinuous, strongly constricted; surface with sensory pores throughout the area; basolateral process 2x longer than wide.

Female redescription. Externally similar to male, except by the ventrites I–V without tomentum on disc. Length: mean = 1.78 mm; width: mean = 0.85 mm (n = 3). Tergite VIII ( Fig. 10B ) 1.5x wider than long; posterior margin rounded; surface covered by setae (more abundant on anterior region), spines and microspines. Sternite VIII ( Fig. 10C ): 2x wider than long; anterior median projection 2x longer than the sternite body length; posterior margin with setae; surface with short setae and microspines (more abundant near the apex). Ovipositor ( Fig. 10A ): valvifer anteriorly dilated; 2x longer than the coxites; surface with sensory micropores. Apical coxite 2.2x longer than wide, 1.5x longer than the basal one. Stylus slightly curved, measuring 1/3 the length of the apical coxite; apex with short setae.

Comparative notes. Pilielmis sara resembles Pilielmis baniwa sp. nov. by sharing a subparallel body, antennae bicolor and a pair of marks on the posterior half of the pronotum. However, both species can be easily distinguished as follows: P. sara has yellowish-brown elytra, with black marks; the metaventrite has a pair of short carinae at the base of the discrimen; the male genitalia have the parameres with lateral margins strongly crenulate and the penis is 2.5x longer than wide, with a strong constriction at the middle of the lateral margins. In P. baniwa sp. nov. the elytra are black, with yellow marks, the pair of short carinae at the base of the discrimen is absent, the male genitalia have parameres with smooth lateral margins and the penis is 4x longer than wide, without a strong constriction at the middle of the lateral margins.

Distribution: Brazil (Amazonas) ( Fig. 1 ).

Material examined. Paratypes: Brazil: Amazonas, Manaus, ix.1937, H.E. Hinton (3♂ and 3♀ in NHMUK) . Additional material. BRAZIL, Amazonas: Presidente Figueiredo , 13-15.vi.2008 , 2°01′S; 59°43′W, Fernandes et al. leg., (alcohol) (2♀ in INPA) .

Figures

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

FIGURE 7. Pilielmis sara Hinton, 1971 (Coleoptera: Elmidae). Adult, male, habitus (Paratype). (A) Dorsal view. (B) Ventral view. (C) Lateral view. (D) Front view. Scale bars = 0.5mm.

FIGURE 8. Pilielmis sara 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 9. Pilielmis sara Hinton, 1971 (Coleoptera: Elmidae). Adult, male. Paratype. (A) Genitalia, ventral view. (B) Tergite VIII, dorsal view. (C). Sternite VIII, dorsal view. (D) Metathoracic wing. (E) Segment IX, ventral view.

FIGURE 10. Pilielmis sara 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.