Simulium (Hearlea) paracarolinae Coscarón, 2004

Coscarón, S., Esquivel, D. R. Miranda, Moulton, J. K., Arias, C. L. Coscarón- & Bernal, S. Ibañez, 2004, Simulium (Hearlea) Vargas, Martínez Palacios, & Díaz Nájera (Diptera: Simuliidae): Taxonomic revision and cladistic analysis, Zootaxa 396, pp. 1-52 : 32

Simulium (Hearlea) paracarolinae Coscarón , n. sp.

Figs. 8I–L , 9B, C .

Larva: Length (mature), 7.0– 8.5 mm. Coloration light brown yellowish (in alcohol). Cephalic apotome light brown, darkened basally, with darkened median longitudinal stripe on basal one­third and 1+1 small submedian spots near midline. Labral fan with 44–48 primary rays. Medial antennal article with 4 pseudoannulations ( Fig. 8K ). Ratio of antennal articles = 1:1.6:1.0 (proximal: medial: distal). Postgenal cleft subtriangular, without anteromedian incision ( Fig. 8I ). Ratio of hypostoma/hypostomal bridge = 1.2. Hypostoma with median tooth longer than others; 11–12 lateral and 2 discal setae per side. Mandible with internal teeth arranged in 3–4 rows of 6–8 teeth; 2 marginal teeth, second one very small ( Fig. 8L ); lateral process elongated, stout, and curved. Lateral sclerite of thoracic proleg with 42–46 teeth. Anal sclerite with ventral struts heavily sclerotized, relatively short, not encircling posterior circlet although enclosing approximately 1/3 of it; accessory plates comprised of 1+1 well sclerotized, dorsolateral conical plates covered with small setae ( Figs. 9B, C [ds]). Segment VIII lacking ventrolateral papillae. Posterior circlet with 398– 400 rows of 42–48 hooks. Rectal papillae trilobed, with 6–7 lobules per lobe (18–21 total), the median lobe largest.

Material examined: Guatemala: Solala , Atitlan , Santa Alicia , Finca Monte de Oro, río Catarata, (12 K, 36 B), Holotype larva and Paratype 1 larva, 24 March 1951, H. Dalmat ( AMNH) ; same locality, 6 larvae, 22 February 1945, ( AMNH) ; unknown locality XXII, 3 lots: (5 larvae), (1 larva), (7 larvae, 2 larvae on slides) ( AMNH) ; XVII, 2 lots (2 larvae in slide) ( MLP) .

Discussion: Larval morphology permits differentiation of S. paracarolinae from all other known species. The presence of accessory plates on the anal sclerite and a curved anterior hypostomal margin place this species into the S. carolinae group, for which the larva is known for all species. Although the larva cannot be completely ruled out from being the unknown larva of S. nigricorne , pupal morphology suggests the latter species corresponds to a group having different larval characters, such as absence of accessory plates on the distal abdomen, straight anterior hypostomal margin, distinct mandible morphology, and postgenal cleft. The closest species is S. carolinae , but its anal sclerite ventral struts completely encircle the posterior circlet and has 2+2 dorsolateral accessory plates.

Figures

FIGURE 8. Larva A–C. S. (H.) capricorne A. head capsule, ventral view; B. hypostoma. C. mandible, distal portion. D–G. S. (H.) gorirossiae, D. cephalic apotome (basal portion) with cervical sclerites, E. antenna, F. mandible, ventral view; G. mandible, distal portion. H. S. (H.) larvispinosum, head capsule, ventral view. I–L. S. (H.) paracarolinae n. sp. I. head capsule, ventral view; J. hypostoma dental border; K. antenna, L. mandible, distal portion. (A–D), (B, J), (E, K), (H, I) same scale respectively.

FIGURE 9. A–J. Anal sclerite and accessory plates of larva. (d = dorsal branch of anal sclerite; v = ventral branch of anal sclerite; ds = dorsolateral conical accessory plate single; dd = dorsolateral conical accessory plates double; vl = ventrolateral accessory plate; df = dorsolateral flattened accessory plate). A. S. (H.) capricorne; B, C. S. (H.) paracarolinae B. dorsal view (cleared), C. posterodorsal view; D–F. S. (H.) gorirossiae D. posteroventral view, E. posterodorsal view, with rectal papillae (ap); F. ventrolateral papillae (vp) of segment VIII, sclerotized apical region; G. S. (H.) larvispinosum, lateral view, H. dorsal view, I. ventral view (cleared), J. S. (H.) temascalense. lateral view. (B, H, J) and (C, D, E) same scale respectively.