Gravatamberus, Mendes & Andersen, 2008

Mendes, Humberto Fonseca & Andersen, Trond, 2008, A review of Antillocladius Saether and Litocladius Mendes, Andersen et Saether, with the description of two new Neotropical genera (Diptera, Chironomidae, Orthocladiinae), Zootaxa 1887 (1), pp. 1-75 : 41-43

publication ID

https://doi.org/ 10.11646/zootaxa.1887.1.1

persistent identifier

https://treatment.plazi.org/id/5C31878A-FFD2-FFE0-6AAD-FB0952BFA505

treatment provided by

Felipe

scientific name

Gravatamberus
status

gen. n.

Gravatamberus gen. n.

Gen. n. 2 Pinho et al., 2005: 46.

Type species: Gravatamberus nidularium sp. n. by present designation.

Other included species: G. apicalus sp. n., G. curtus sp. n., G. guatemaltecus sp. n., and G. pilosus sp. n.

Etymology: From the native Brazilian language Tupy, gravata, meaning bromeliad, pineapple, and mberu, meaning midge, mosquito, small insect. Both words combined thus mean "the midge that inhabits bromeliads". Gender of genus: masculine.

Diagnostic characters: The imagines can be separated from all other orthoclad genera by having scalpellate acrostichals combined with no anal point; stout seta on the tip of the antenna; eyes bare, without dorsomedian extension; and hairy wings with R 4+5 ending proximal to M 3+4. The combination of absence of thoracic horn, wing sheath with nose, two macrosetae on spined tubercles and caudal row of spines on tergites II–VIII will separate the pupa from all other orthoclad genera. The larva is similar to those of Compterosmittia , Limnophyes , Paralimnophyes , and Genus H sensu Epler, but can be recognized by the single median tooth of the mentum and the pair of setal tufts on the abdomen..

Generic diagnosis:

Male. Small, wing length about 1.0 mm.

Antenna. With 12–13 flagellomeres, 12th and 13th flagellomeres may be distinct to completely fused; groove beginning on flagellomere 2; sensilla chaetica on flagellomeres 2, 3 and 13 (12 when fused); apex rounded with stout setae; fully plumed. Antennal ratio about 0.50.

Head. Eye bare, without dorsomedian extension. Temporal setae strong, consisting of inner verticals, outer verticals, and postorbitals. Third palpomere about as long as fourth, with two long, weak lanceolate sensilla clavata subapically.

Thorax. Antepronotum well developed with lobes meeting medially, with few lateral setae. Acrostichals strong, in mid scutum, apparently all scalpellate, uniserial to irregularly biserial; dorsocentrals beginning close to antepronotum, anterior uniserial, posterior biserial; prealars few, uniserial; supraalars present. Scutellars uniserial.

Wing. Membrane with setae, with moderately coarse punctuation (visible at 250X magnification). Anal lobe weakly developed. Costa moderately to strongly extended. R 2+3 running and ending midway between R 1 and R; R 4+5 ending proximal to M 3+4; Cu 1 nearly straight; FCu distal to RM. Postcubitus ending distal to FCu, An ending below FCu. Veins with setae except for R 2+3. Brachiolum with one seta. Squama bare.

4+5

Legs. Pseudospurs, sensilla chaetica, and pulvilli absent.

Abdomen. Tergites and sternites with few setae.

Hypopygium. Tergite IX rounded posteriorly without anal point, covered with microtrichia, without or with few setae. Laterosternite IX setose. Sternapodeme slightly arched, oral projection well developed. Virga absent. Gonocoxite with well developed inferior volsella. Gonostylus with well developed, rounded crista dorsalis.

Female: Unknown.

Pupa: Small, about 1.80 mm long. Exuviae transparent.

Cephalothorax. Frontal setae absent, frontal apotome smooth. Head smooth, antennal pedicel sheath with weak pearl row. Ocular field apparently with one vertical and one postorbital. Thoracic horn absent. Setation: 3 antepronotals, 3 grouped dorsocentrals, 3 precorneals and 1 prealar. Thorax smooth. Wing sheath with nose.

Abdomen. Tergite I bare, tergites II–IX and sternites IV–VIII with shagreen, extensive on tergites, coarse on sternites. Conjunctives II/III, III/IV, IV/V and V/VI with small spines. Tergite II without caudal hooklets. Tergites II–VIII with single caudal row of spines, no caudal spines on sternites. Pedes spurii A and B absent. Segments II–VII apparently with 2 L–setae, one of them strong, about half the length of segments. D, V and O setae present, but weak. Anal lobe with 2 subequal hooked macrosetae about three and a half times the length of anal lobe and situated on spined tubercles. Genital sac of male rounded, overreaching apex of anal lobe.

Larva: Small, about 2.10 mm long.

Head. Antenna with 5 segments, basal segment shorter than flagellum; third antennal segment nearly as long as fourth, segments 3 and 4 more sclerotized basally. Basal antennal segment nearly twice as long as basally wide, with ring organ situated medially. Lauterborn organs weak, style well developed. Blade longer than flagellum, accessory blade apparently absent. S I plumose. Other S setae simple. Labral lamella apparently absent. Few spinulae and chaetae. Pecten epipharyngis consisting of two pointed teeth. Chaetulae laterales and chaetulae basales apparently simple. Premandible with 3 apical teeth, with third about half as long as second apical; without brush. Mandible with apical tooth shorter than combined width of inner teeth. Fourth inner tooth fused with mola, but distinct. Seta subdentalis slender, curved; seta interna with apparently 7 branches, shorter branches with rounded apex, longer branches pectinate or plumose apically. Mentum with 1 median tooth and 5 pairs of lateral teeth of which median tooth slightly smaller than the first lateral. Ventromental plates inconspicuous, beard absent. Setae submenti just below base of ventromental plates. Maxilla and maxillary palp apparently normally developed.

Abdomen. Anterior and posterior parapods well developed; claws of parapods smooth. Procercus minute with about 9 long anal setae, supraanal seta weak. Anal tubules apparently absent. Abdominal segments with one pair of setal tufts.

Taxonomy: The males key to Apometriocnemus in Cranston et al. (1989) due to the lack of anal point; to Tosacladius Sasa, Suzuki et Sakai in Saether et al. (2000); and to Botryocladius Cranston et Edward in Mendes et al. (2004). The pupa keys to couplet 94 in Coffman et al. (1986), but does not correspond to the two alter- natives, Gymnometriocnemus or Metriocnemus ; in Saether et al. (2000) it will key to Metriocnemus . The larva keys to Limnophyes in Cranston et al. (1983) and Saether et al. (2000), and to Compterosmittia in Epler (2001).

The pupa shares absence of thoracic horn and row of spines caudally on the tergites with Antillocladius and Gynocladius , but the nose on the wing sheath must be considered to be an autapomorphy. The larva shows clear similarities with Gynocladius , Limnophyes , Paralimnophyes , Compterosmittia and Genus H sensu Epler.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Chironomidae