Chagasia ablusa Harbach

Harbach, Ralph E. & Howard, Theresa M., 2009, Review of the genus Chagasia (Diptera: Culicidae: Anophelinae), Zootaxa 2210, pp. 1-25 : 5-6

Chagasia ablusa Harbach , new species

Chagasia fajardoi of Komp, 1936: 66 ( Colombia, Ƥ L P, bionomics); Gast Galvis, 1943: 5, 8, 9, 19 ( Colombia, 3 Ƥ L);? Romeo Viamonte & Castro, 1951: 319, 324, Fig. 12 (Ƥ*); Gabaldon & Cova-Garcia, 1952: 179, 197, 198, Fig. 8H (in part,? Bolivia, Colombia); Lane, 1953: 139 –144 (in part, Colombia, 3* Ƥ E* L* P*); Horsfall, 1955: 41 (distribution, L, bionomics); Stone et al., 1959: 10 (in part, catalogue, Colombia); Cova-Garcia, 1961: 181 –183 (? Venezuela, A, identification).

Chagasia fajardi of Russell et al., 1943: 35, 39, 42 (Ƥ L, bionomics, distribution); Knight & Stone, 1977: 68 (in part, catalogue, Colombia); Guimarães, 1997: 30 (in part, catalogue, Colombia).

Diagnosis. The adults of Ch. ablusa are distinguished from those of other species of Chagasia as follows: front of anterior promontory with yellow scales contiguous and well-contrasted with white dorsocentral scales (distinction from Ch. fajardi ); acrostichal scales pale anteriorly, dark posteriorly (as in Fig. 3 B) (distinction from Ch. bathana and Ch. bonneae ); without pale scales on mesal margin of supraalar scales (distinction from Ch. fajardi ); wing dark-scaled with speckling of pale scales on proximal half of costa (distinction from Ch. bathana and Ch. bonneae ), vein R4+5 with distinct cluster of darker scales at base; hindtibia with distinct semierect clusters of dark scales ( Fig. 4 A) (distinction from Ch. fajardi and Ch. rozeboomi ); hindtarsomeres 2–5 without postbasal dark bands (distinction from Ch. bathana ), basal pale band of hindtarsomere 2 usually very long, 3.17–10.33 (mean = 5.89) length of apical dark band ( Fig. 5 D) (92% distinction from Ch. fajardi ), hindtarsomere 5 with apical dark band (distinction from Ch. bonneae ). Males are distinguished by the presence of a single stout specialised seta on the dorsomesal prominence of the gonocoxite (unique) and fine setae on the claspette (distinction from Ch. bathana and Ch. bonneae ). Larvae are distinguished by the development of certain setae: setae 5- and 7-C are long (distinction from Ch. rozeboomi ); seta 5-C is inserted anterior to the base of the antenna on a line midway between the insertions of setae 4- and 7-C, the rachis (main stem) of 5-C reaches the base of seta 4-C and the distance between the insertions of the 2 seta 5-C is less than the distance between the insertions of setae 4- and 7-C (distinctions from Ch. bathana , Ch. bonneae and Ch. rozeboomi ); setae 11- and 13-C are about the same length and shorter than the antenna, about twothirds as long (distinction from Ch. bathana , Ch. bonneae and Ch. rozeboomi ); seta 15-C is single and long (distinction from Ch. bonneae ); and seta 1-P has long aciculae that arise near the middle of each primary branch (distinction from Ch. rozeboomi ). Pupae have no diagnostic features but they differ from pupae of Ch. bonneae in lacking a ligulate process on the rim of the trumpet.

Etymology. The specific name ablusa is the feminine form of the Latin adjective ablusus, which means ‘different’.

Discussion. Chagasia ablusa has been misidentified as Ch. fajardi in the past based on superficial similarities of the adults. Whether or not these similarities indicate that Ch. ablusa is more closely related to Ch. fajardi than to the other species of Chagasia is a moot question. The structure of the male genitalia and the darkly scaled wings and posterior dorsocentral area suggest that Ch. ablusa , Ch. fajardi and Ch. rozeboomi are more closely related to one another than either is to Ch. bathana and Ch. bonneae . Until the larva of Ch. fajardi is known with certainty (see below), it is pointless to speculate on relationships based on larval morphology. Because Chagasia is a small homogeneous assemblage of species that exhibit a paucity of anatomical distinctions, molecular data will probably be needed to resolve phylogenetic relationships within the genus.

Distribution. Colombia, Peru and? Venezuela. Published reports of Ch. fajardi in Venezuela (see above) probably refer to Ch. ablusa based on its proximity and topographic similarity to Colombia, but this requires confirmation as specimens from Venezuela were not available for study. Chagasia ablusa surely occurs in Ecuador and is likely to be present in western Bolivia. In fact, reports of Ch. fajardi in the latter country (see below) may refer to this species.

Material examined. Type series: Twenty specimens (10Ƥ, 13, 13G, 3Le, 3Pe, 2L). HOLOTYPE, female (PE 288-1), with LePe on microscope slide, PERU: Junín, Satipo, Mission Cutivireni (12 S 74 W), 400 m, 10 March 1985 (Calderone), WRBU ACC 1131. Paratypes, 1ƤLePe (PE288-4), 13 with dissected genitalia (PE 288-105), 1L (PE 288), same data as holotype; 5Ƥ (PE 359), same as holotype except 22 March 1985 (Hayes, Harrison & Savage); 1Ƥ (PE 357), same as holotype except 21 March 1985 (Victor Lugo & others); PE 467- 16 (1ƤLePe), 1L (PE 467a) Madre de Dios, Rio Manu, Pakitza (11° 55' 48" S 71° 15' 18" W), 250 m, 31 October 1990 (Wilkerson, Gaffigan & Mallampalli), WRBU ACC 1445. The type series is deposited in the National Museum of Natural History, Smithsonian Institution, Washington, DC, USA.

Other material examined: Sixty-one specimens, COLOMBIA, Meta, Restrepo (1Ƥ, 23, 13G), Villavicencio (15Ƥ, 53, 13G, 13Le, 14Pe, 4L); unknown locality (1Ƥ).

Figures

FIGURE 3. Scutum (dorsal view) of (A) Chagasia bonneae and (B) Ch. fajardi. The acrostichal scales (red arrows) are entirely pale in Ch. bonneae and dark posteriorly in Ch. fajardi (some scales have been lost in specimen shown); pale para-supraalar scales (yellow arrows), absent in the former species, are often present in the latter species. Note that the dorsocentral scales on the anterior promontory are distinctly yellow in Ch. bonneae but more or less unicolorous with the other dorsocentral scales in Ch. fajardi.

FIGURE 4. Hindtibia (anterior view) of (A) Chagasia ablusa and (B) Ch. fajardi showing the presence and absence of semi-erect clusters of dark scales, respectively.

FIGURE 5. Hindtarsus (anterior view) of (A) Chagasia bathana, (B) Ch. bonneae, (C) Ch. fajardi, (D) Ch. ablusa and (E) Ch. rozeboomi.