Inaequalium maranguapense, Pessoa, Felipe Arley Costa, Velásquez, Claudia María Ríos & Py-Daniel, Victor, 2005

Pessoa, Felipe Arley Costa, Velásquez, Claudia María Ríos & Py-Daniel, Victor, 2005, First survey of Simuliidae (Diptera) from the North of Ceará State, Brazil, with description of a new species and identification keys for the immature stages, Zootaxa 1051, pp. 1-18 : 5-14

Inaequalium maranguapense new species Pessoa, Ríos­Velásquez & Py­Daniel

( Figs. 2–8 )

Female. General body color dark (n = 2; specimens preserved in alcohol; thoracic pattern not illustrated as the female is described based on pharate specimens). Head: dichoptic, eyes black, frons higher than wide, indices: 1.4–1.6 ( Fig. 2 a), fronto­ocular triangle well developed, without infraocular suture ( Fig. 2 b). Cibarium with 4 rows of well­sclerotized acuminate teeth medially, without central elevation or pronounced central area ( Figs. 2 c, d). Antenna length 0.37–0.40 mm; flagellum dark. Sensorial organ of maxillary palps spherical, occupying 1/2 to nearly 1/3 length of basal article, palpomere V 2.3–3.0 times as long as palpomere IV, palpomeres III and IV equal (ratio III:IV: V 1:1:2.3–3.0) ( Fig. 2 e). Mandible with 8 external serrations and 28–33 internal teeth; maxillary lacinia with 13 or 14 external, 1 central and 9 or 10 (may be 1 rudimentary tooth) internal retrorse teeth ( Fig. 2 f).

Thorax: wing length 1.7 mm, width 0.7 mm; Sc and R2 wing veins with setae, R1 with setae and spines, including setae in the basal area ( Fig. 3 a). Leg ( Fig. 3 b): Foreleg with coxa, trochanter, femur, and basal 3/4 of tibia pale, distal 1/4 of tibia and all tarsal segments dark. Middle leg with coxa and trochanter dark; basal 1/2 of tibia, basal 4/5 of first tarsal segment, basal 1/2 of second tarsal segment pale; distal 1/2 of tibia, distal 1/5 of first tarsal segment, distal 1/2 of second tarsal segment, and rest of tarsi dark. Hind leg with coxa, distal 1/3 of femur, distal 1/2 of tibia, distal 1/4 of first tarsal segment, and rest of tarsi dark; trochanter and basal 2/3 of femur pale; basal 1/2 of tibia and basal 3/4 of first tarsal segment pale. Tarsal claws curved with basal tooth ( Fig. 3 c) on hind legs. Calcipala and pedisulcus present.

Gonapophysis subtriangular, with microtrichia only on basal part, divergent below with sclerotized internal borders ( Fig. 3 d). Genital fork stout and sclerotized, stem longer than lateral arms, lateral arms forming suboval space ( Fig. 3 e). Cerci rounded, covered with brown setae; paraproct subrectangular, cercus higher than paraproct, paraproct larger than cercus ( Fig. 3 f). Spermatheca subspherical, with cuticular microspines, spermathecal ducts and area of attachment unpigmented ( Fig. 3 g).

Male: unknown.

Pupa: General coloration light brown, gill pale. Dorsal cocoon length 1.7–2.4 mm (mean = 2.1 mm; n = 9), ventral cocoon length 2.6–3.1 mm (mean = 2.8 mm; n = 9), gill length 1.3–1.8 mm (mean =1.6; n = 8). Cocoon light brown, slipper shaped without anterior projection and not covering gill base; cocoon fibers thick with spaced woven threads ( Fig. 4 a).

Frontoclypeus with moderately abundant rounded platelets; 1+1 long, hairlike, bifid facial trichomes and 2+2 bifid frontal trichomes as long as facial trichomes ( Fig. 4 b), external surface of antennal sheaths not covered with tubercles.

Gill with 4 filaments directed forward, main trunk bulbous, immediately giving rise to 4 terminal branches, grouped in 2 dorsal and 2 ventral branches, equal or subequal in length, gill formula 1(4); branches inflated basally and narrowing distally; surface of filaments covered with small rounded tubercles, apex of all filaments digitiform ( Fig. 4 c). Thorax with 5+5 hairlike anterodorsal trichomes with 3–5 branches, basally widened, narrowing in apical 1/3, with coiled tip; 1+1 supralateral, 3+3 lateral simple hairlike trichomes. Platelets of thorax moderately abundant, rounded, smaller than point of insertion of thoracic trichomes ( Fig. 4 d).

Abdominal tergite I with 1+1 hairlike setae sublaterally; tergite II with 5+5 spiniform setae ( Fig. 5 a); tergites III and IV with 4+4 anteriorly directed hooks ( Fig. 5 b) on posterior margin, 1+1 spiniform setae between 1+1 outermost hooks, and 2+2 spiniform setae sublaterally; tergite V with 3+3 submedian hairlike setae, tergites VI–VIII with 2+2 submedian hairlike setae and with 1+1 comblike groups of small and large posteriorly directed spines on anterior margin. Pleural membrane usually with 2 or 3 small simple setae per segment. Tergite IX with 1+1 small curved terminal spurs ( Fig. 5 d). Abdominal sternite III with 2+2 lateral simple setae on anterior margin, and spine combs in median region of anterior margin. Sternites IV–VIII with 1+1 groups of spine combs in median region of anterior margin ( Fig. 5 c). Sternite IV with 1+1 submedian simple or bifid small hooks and 2+2 simple submedian setae on anterior margin among groups of spine combs; sternite V with 2+2 bifid to 5­branched hooks ( Fig. 5 c); and 2+2 submedian setae lateral to outermost hooks; sternites VI–VII with 2+2 simple to trifid submedian hooks and 1+1 simple setae between them. Sternites V to VII with longitudinal median striations.

Larva (last instar): Abdomen length 3.8–4.5 mm (mean = 4.1 mm; n = 10); head capsule lateral length 0.35–0.4 mm (mean = 0.37 mm; n = 10); dorsal width 0.4–0.48 mm (mean = 0.41 mm; n = 10). General coloration (in alcohol) white with dorsal greenish stripes along body, without fixed pattern ( Fig. 6 a). Cephalic apotome yellowish brown with pattern of spots as in Fig. 6 b, and with small simple setae. Subesophageal ganglion unpigmented. Cervical sclerites small, elliptical, not fused to postocciput, free in membrane ( Fig. 6 b).

Antenna longer than stem of cephalic fan ( Fig 6 c); distal, medial, and proximal articles of different size; first article larger than second, and third article larger than first and second, ratio (first article to third) 1:1.14–1.17: 1.81–1.87 (n = 5). Hypostomium with central tooth slightly larger than 1+1 corner teeth, 3+3 intermediate teeth, l+1 small teeth (median intermediate tooth slightly smaller than others), 2+2 lateral teeth, 3–5 lateral serrations, 4 or 5 hypostomal setae per side, with branched tips, and 1+1 setae in distal margin of hypostomal plate ( Fig. 6 d). Postgenal cleft longer than wide, subtriangular. Ratio of hypostomium/hypostomal bridge/postgenal cleft = 1:0.65–0.71:1.42–1.45 (n = 5) ( Fig. 6 e).

Cephalic fan with 39–41 primary rays, rows of microtrichia of primary ray following weak complex pattern (Palmer & Craig, 2000) ( Fig. 7 a). Mandible with 1 apical, 2 external, 3 subapical teeth (third smaller than second and both smaller than first), 12 or 13 internal teeth apparently divided into 2 rows, superior ridge with 4 or 5 teeth, and inferior ridge with 8 teeth, first internal tooth subequal to first subapical tooth. Lateral mandibular process present, simple, not bifurcated, with single proximal sinuosity and reaching inferior margin of mandible, 2 marginal teeth: first large, second small to residual ( Fig. 7 b). Labral sclerite subtrapezoidal, covered with long setae and with 3+3 apical teeth ( Fig. 7 c–d).

Proleg of thorax with lateral sclerites subrectangular, with apical fringe of bristles, divided into 7–9 groups of combs with 3–7 bristles in each comb ( Fig. 7 e). Gill histoblast in situ as in Fig. 8 a.

Abdomen with few simple setae distally on anterodorsum; anal sclerite X­shaped, anterodorsal arms shorter than posteroventral arms ( Fig. 8 b). Anal ring with 81–83 rows of 9–13 hooks in each row. Anal gill with 3 simple lobes (most of examined larvae, n = 25) ( Figs. 8 c–f). Lobules when present small, few in number (2 or 3 lobules on 1 or 2 lobes), and only in 2 larvae ( Figs. 8 e–f). Ventral tubercles well developed, subtriangular ( Fig 8 d).

Taxonomic remarks. This new species is a member of the genus Inaequalium , as defined by Coscarón & Wygodzinsky (1984). The characters that justify inclusion in this genus are as follows: adult wings with setae on the basal region of R; basal portion of female cibarium with prominent teeth; pupa with thoracic trichomes with three or more branches and inflated gill filaments; and larva with the third antennal article longer than the remaining segments.

The female of I. maranguapense n. sp. can be distinguished from those of other species in the genus Inaequallum, except I. souzalopesi (Coscarón) , by possessing a cibarium lacking the typical central elevation that characterizes the genus, and lacking a deep central area, which characterizes Psaroniocompsa Enderlein and Cerqueirellum (Py­ Daniel). Inaequalium maranguapense n. sp. can be distinguished from I. souzalopesi by the shorter paraproct. The pupal gill configuration of Inaequalium maranguapense n. sp. can be distinguished from that of all congeners based on the four terminal gill filaments being inflated proximally before narrowing distally and all filaments arising from the same point. Pupae of I. travassosi (d’Andretta & d’Andretta) can have three or four terminal gill filaments, but these have a clear bifurcation in the main trunk, with a dorsal primary branch (which can be bifurcated distally) and a small ventral primary branch, giving rise to two terminal filaments, and no filaments narrowing distally. Inaequalium maranguapense sp. n is unique within Inaequalium in that the larva has rectal papillae comprised of simple lobes or lobes with only a few lobules. According to Adler et al. (2004), these distinctive papillae are similar to those of Parasimulium Malloch, Prosimuliini , and some Simuliini (sensu Crosskey & Howard 1997). One member of the Prosimuliini (sensu Crosskey & Howard 1997), Gigantodax multifilis ( Wygodzinsky & Coscarón 1989) , has multiple lobules on the rectal papillae. This observation and other conflicting characters reinforce the idea of Py­Daniel & Moreira­Sampaio (1994) to eliminate the tribal levels until more studies of the different simuliid groups are conducted. We decided not to include Inaequalium maranguapense n. sp. in any of the Inaequalium species groups of Strieder & Py­Daniel (2002); this species has morphological characters of both the botulibranchium and inaequale species groups. A review and phylogenetic analysis of the genus Inaequalium is being conducted, which should define the taxonomic position of Inaequalium maranguapense .

Etymology. The species name maranguapense refers to the type locality. Maranguape Municipality ( Fig. 1 ) is a small, pleasant place near Fortaleza, the capital of Ceará State, Brazil.

Bionomics. Larvae and pupae were collected from rocks and deciduous leaves in poorly lit riffles. The stream at the type locality is small during the dry season (width = 0.5 m, depth = 5 cm), with a mostly bedrock bottom. This species was associated with larvae and pupae of Hemicnetha rubrithorax (Lutz) , Inaequalium subnigrum (Lutz) , a species similar to Ectemnaspis kabanayense (Ramírez­Pérez & Vulcano) , and larvae of Trichoptera, Plecoptera, and Diptera ( Psychodidae and Chironomidae ).

Examined material. Holotype: pharate female with pupal exuviae mounted on slide ( INPA n o 6286). Paratypes: 1 pharate female with pupal exuviae mounted on slide; 5 slidemounted larvae and 2 slide­mounted pupal exuviae; 25 larvae and 5 pupae in alcohol; all specimens from a small tributary of Gavião River, near Erundina Hotel, Balneário Cascatinha road, Maranguape mountain, approximately 600 meters above sea level, Maranguape Municipality, Ceará State.

Figures

FIGURE 1. Map of Ceará State, Brazil, showing the points of sampling.

FIGURE 2. Female of Inaequalium maranguapense sp. n. a: part of head, frontal view; b: detail of fronto­ocular area; c: cibarium; d: detail of teeth of cibarium; e: palpus; f: mandible and maxillary lacinia. Abbreviations: FOA = fronto­ocular area; MD = mandible; ML = maxillary lacinia.

FIGURE 3. Female of Inaequalium maranguapense sp. n. a: detail of wing chaetotaxy; b: legs; c: tarsal claws; d: spermatheca; e: gonapophyses; f: genital fork; g: cerci and paraprocts, lateral view. Abbreviations: FL = fore leg; ML = mid leg; HL = hind leg

FIGURE 4. Pupa of Inaequalium maranguapense sp. n. a: general dorsal view; b: part of frontoclypeus with frontal and facial trichomes; c: gill filaments, lateral view; d: part of thorax with anterodorsal trichomes; arrow points to coiled trichome tip.

FIGURE 5. Abdomen of pupa of Inaequalium maranguapense sp. n. a: detail of abdominal tergite I; b: detail of tergites III and IV; c: detail of sternites IV and V; arrow points to five­branched hook; d: detail of tergite IX; arrow points to 1 + 1 terminal spur.

FIGURE 6. Larva of Inaequalium maranguapense sp. n. a: coloration pattern, lateral view; b: cephalic apotome, arrow points to cervical sclerite; c: antenna and stem of cephalic fan; d: hypostomium; e: postgenal cleft, hypostomal bridge, and hypostomium.

FIGURE 7. Larva of Inaequalium maranguapense sp. n. a: cephalic fan, row of microtrichia of primary ray; b: mandible, arrow points to mandibular process; c – d: labral sclerite, arrow points to one of the apical teeth; e: detail of thoracic proleg; arrow points to lateral sclerite.

FIGURE 8. Larva of Inaequalium maranguapense sp. n. a: gill histoblast; b: anal sclerite; c – f: types of rectal papillae; arrow points to ventral tubercle.