Pilielmis apama 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 : 25-30

Pilielmis apama Hinton, 1971

( Figs 1 , 15–18 , 41D )

Pilielmis apama Hinton, 1971 a: 165 (original description).

Diagnosis. Body subparallel; general coloration light brown; antennae bicolor: antennomeres I and II yellow, antennomeres III–XI blackish; pronotum with a yellowish mark approximately on anterior 1/3; elytra with yellowish marks (a pair at the base of the humerus, an elongated pair on the posterior half, and a mark at the apex along the elytral suture). Male with phallobase 2.3x longer than wide; parameres reaching approximately 3/5 the length of the penis, narrower medially; penis 4.4x longer than wide; basolateral process 7.2x longer than wide.

Male redescription. Length: mean = 1.66 mm; width: mean = 0.69 mm (n = 5). Body subparallel ( Figs 15A , 41D ); general coloration light brown, with yellowish marks.

Head. Antennae bicolor: antennomeres I and II yellow, antennomeres III–XI black ( Fig. 15B, D ). Labrum ( Fig. 16A ) subrectangular, with lateral margins rounded; anterolateral margins with long setae; dorsal surface with short, sparse setae along its entire length. Mandibles ( Fig. 16C, D ): lateral lobe projected; posterolateral angle rounded, with a groove on the disc; condyle rounded, 1.5x wider than long. Maxilla ( Fig. 16B ): cardo 2x wider than long, lateral margin sinuous; stipe subrectangular; maxillary palpus with palpomere IV elongated, as long as the basal ones combined, with rounded apex, without setae; galea with apical section subtriangular, 5x longer than the basal one, apex rounded, with a tuft of long, thin setae; lacinia subrectangular, 2x longer than wide, with long setae on inner lateral margin. Labium ( Fig. 16E ): postmentum subrectangular, 3x wider than long, lateral margins rounded; prementum subrectangular, 4x wider than long, lateral margins rounded; ligula 2x wider than long, anterior margin sinuous, lateral margin rounded, surface covered by setae; gula 2x wider than long, lateral margin straight; labial palpomere III with rounded apex.

Thorax. Pronotum ( Fig. 15A ) slightly wider (0.52 mm) than long (0.43 mm); lateral margins sinuous, with crenulations; anterolateral angles rounded, posterolateral angles acute; with a yellow mark approximately on the anterior 1/3; with a pair of sinuous, weakly raised sublateral carinae; longitudinal impression on the disc deep and wide. Elytra ( Fig. 15A ) subparallel, 1.8x longer than wide (length = 1.15 mm; maximum width = 0.68 mm); apex rounded; strongly punctuated; with yellowish marks (a pair at the base of the humerus, an elongated pair on the posterior half and a mark at apex along the elytral suture). Scutellum suboval. Metathoracic wings present ( Fig. 17D ). Hypomeron 4x longer than wide. Prosternum ( Fig. 15B ) longer than wide; anterior margin truncated; anterolateral angles rounded. Prosternal process ( Fig. 15B ) wider (0.22 mm) than long (0.13 mm). Mesoventrite ( Fig. 15B ) wider (0.24 mm) than long (0.08 mm); posterior margin truncated between the mesocoxae; cuticle similar to prosternum. Metaventrite ( Fig. 15B ) wide; disc flat; lateral margins covered by tomentum; conspicuous discrimen in the basal half. Hind legs ( Fig. 15B ). Trochanter 2x longer than wide. Femora 3.5x longer than wide. Tibiae 6.7x 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–IV without tomentum on disc; ventrite V with golden setae ( Fig. 15B ). Tergite VIII ( Fig. 17C ) 1.3x wider than long, posterior margin rounded; surface covered by thin setae, spines and microspines. Sternite VIII ( Fig. 17B ) approximately 3x wider than long; surface with microspines and long, thin setae near the apex; anterior median projection 2x longer than the sternite body length. Segment IX ( Fig. 17E ) subtriangular, with rounded apex; anterolateral margin with sensory pores and microspines. Genitalia ( Fig. 17A ). Phallobase 2.3x longer than wide. Parameres 3.4x longer than wide, reaching approximately 3/5 the length of the penis; base wider than apex; narrower medially; rounded apex; lateral margins without crenulations. Penis 4.4x longer than wide, lateral margin sinuous; apical region rounded; surface with sensory pores throughout the area; basolateral process 7.2x longer than wide.

Female redescription. Externally similar to male. Length: mean = 1.72 mm; width: mean = 0.70 mm (n = 5). Tergite VIII ( Fig. 18B ) wider than long, posterior margin rounded; surface with long setae (more abundant on anterior region) and short setae, spines and microspines. Sternite VIII ( Fig. 18C ) 2.3x wider than long; anterior median projection 2x longer than the sternite body length; posterior margin with setae; surface with short setae and microspines. Ovipositor ( Fig. 18A ): valvifer 2x longer than the coxites, posterior region with sensory pores. Apical coxite 1.8x longer than wide, 1.6x longer than the basal one. Stylus slightly curved, measuring 1/3 the length of the apical coxite.

Intraspecific variation. Apical region of the penis slightly subtriangular in some specimens.

Comparative notes. As previously discussed, P. apama externally resembles P. halia by sharing a 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. For details about how to differentiate the two species, see the discussion resented for P. halia . González-Córdoba et al. (2015) proposes the first record of this species for Colombia; however, the individual illustrated in this study is externally different from all species currently known for the genus and likely represents a new species.

Distribution: Brazil (Amapá *, Amazonas, Mato Grosso *, Pará*, and Rondônia *), French Guiana, and Suriname * ( Fig. 1 ).

Material examined. Paratypes: French Guiana , St. Laurent, ix.1937, H.E. Hinton (3♂ and 3♀ in NHMUK) . Additional material. BRAZIL. Amazonas: Careiro Castanho, BR 319 km 235, Atil stream, 23.vii.2017, Rafael & Mendes et al. leg., Garcia & Polizei det. 2020 (pin) (6 in INPA); Manicoré, Campos Amazônicos National Park , Veado stream, 25 km BR , 07.vii.2019, 8º26′27.4′′ S, 61°39′37.3′′ W, Desidério et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1♀ in INPA); Apuí, Seringueira River , waterfall , 04.vii.2018, 06º58′05.4′′ S, 60º03′58.7′′ W, Hamada et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol), (9 in INPA): Juma River , BR 156 , 03.vii.2018, 07º11′16.5′′ S, 59º54′32.7′′ W, Hamada et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1♂ and 1♀ in INPA) . Amapá: Tartaugalzinho, Henrique stream, BR 156 , 07.vii.2011, 01º45′56.5′′ S, 50º52′40.5′′ W, Hamada et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1 ♀ in INPA); Serra do Navio, Cachaço River, Fernando waterfall , 02.vii.2010, 00°53′18.3′′ S, 52°01′22.9′′ W, Pes et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (70 in INPA) . Mato Grosso: Pontes e Lacerda, Pindaituba stream , 22.vii.2001, 15º00′51.5′′ S, 59º17′23.5′′ W, Hamada et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1♀ in INPA); Cotriguaçú, Fazenda São Nicolau , vii. 2007, 03°34′49.8′′ S, 47°35′49.9′′ W, Peres et al. leg., Pinedo-Garcia & Polizei det. 2020 (pin) (1 ♀ in INPA) .

Pará: Paragominas , 17.vii.2011, 02°43′39.7′′ S, 46°58′30.0′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1 ♀ in INPA) ; 20.vii.2011, 03°08′49.9′′S, 47°34′30.0′′ W, Brito et al. leg., Garcia & Polizei det. 2020 (alcohol) (3 ♀ in INPA) ; 04.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) ; 21.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) ; 02.vii.2011, 03°34′49.8′′ S, 47°35′49.9′′ W, Brito et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol) (1♀ in INPA) ; Pana River , 09.x.1985, Comander team et al. leg., Pinedo-Garcia & Polizei det 2020 (alcohol), (4 in INPA) . Rondônia: Chupinguia , 25 km BR, stream, 27.vii.2001, 12°26′31.4′′ S, 60°52′53′′ W, Hamada et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol), (2 ♀ in INPA) ; Colorado do Oeste, Cabixi River , 06.ix.2012, 13º15′31.8′′ S, 60º20′04.8′′ W, Hamada et al. leg., Pinedo-Garcia & Polizei det. 2020 (alcohol), (1♂ in INPA) ; SURINAME, Sipaliwini: Kutari River , 2°10.521′N, 56°47.244′W, Short et al. leg., Pinedo-Garcia & Polizei det 2020 (pin) (2 in SEMC) .

Figures

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

FIGURE 15. Pilielmis apama 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 16. Pilielmis apama 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 17. Pilielmis apama Hinton, 1971 (Coleoptera: Elmidae). Adult, male. (A) Genitalia, ventral view. (B) Sternite VIII, dorsal view. (C) Tergite VIII, dorsal view. (D) Metathoracic wing. (E) Segment IX, ventral view.

FIGURE 18. Pilielmis apama Hinton, 1971 (Coleoptera: Elmidae). Adult, female. (A) Ovipositor, ventral view, with partial region of the coxites highlighted. (B) Tergite VIII, dorsal view, with the anterior 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.