Sycorax wampukrum Bravo & Salazar-Valenzuela

Bravo, Freddy & Salazar-Valenzuela, David, 2009, A new species of Sycorax Curtis (Diptera, Psychodidae, Sycoracinae) collected on harlequin frogs (Anura: Bufonidae, Atelopus) in the Ecuadorian Andes, Zootaxa 2093, pp. 37-42 : 38-41

Sycorax wampukrum Bravo & Salazar-Valenzuela sp. nov.

( Fig. 1–13 )

Type material. ECUADOR, Morona Santiago, Río Napinaza (2,92665° S, 78,40701° W, 1010 m.a.s.l.), holotype male, 28.IV.2005, Salazar-Valenzuela, D. (TiposQCAZI 2022); 1 paratype female, same locality, date and collector as holotype (TiposQCAZI 2023); 25 paratype males, same locality, date and collector as holotype (TiposQCAZI 2024–2037, MZUEFS #43842-43851).

Additional studied specimens. 58 males and 11 females preserved in 75% ethanol from the same locality as the holotype, all collected by David Salazar-Valenzuela ( QCAZI 15289 and 15290): 10 males and 4 females, 9.XII.2007; 48 males and 7 females, 1.IV.2008.

Etymology. The name wampukrum is a word in the Shuar language that means “extremely poisonous colorful frog” ( Arbeláez Ortiz 2005). This is the name given by the Shuar people (an ethnic group that inhabits the southeastern region of Ecuador and northeastern Peru) to the Atelopus species inhabiting the area where the specimens of the new species of Sycorax were found. The Shuar word is actually spelled wampukrum (Ernesto Arbeláez Ortiz, pers. comm.), and not wampucrum as used by Arbeláez Ortiz (2005).

Type locality. The specimens of the new species of Sycorax were collected on the margin of Napinaza River on the Amazonian slopes of the Cordillera Oriental in the southern Ecuadorian Andes. The collection locality is situated 6.6 Km north of the central park of General Plaza (also known as Limón) on the main highway to Macas. The vegetation in this region belongs to Foothill Evergreen Forest (Bosque Siempreverde Piemontano, sensu Palacios et al. 1999), although it has largely been cleared for cattle ranching and agriculture, with an annual rainfall of 1500–2000 mm, and annual temperature of 18–22°C ( Cañadas-Cruz 1983).

Diagnosis. First flagellomere 2.1X length of second flagellomere; male genitalia not inverted; gonostylus with a long subterminal hair and three long, thick spines, one of them apical, one preapical and one at middle; aedeagus with one aperture; genital filaments of male terminalia parallel in ventral and dorsal views and Ushaped in lateral view; sternite 8 of female fused to tergite 8; lobes of sternite 8 of female wider dorsally than ventrally

Description. Male. Eyes separated, without eye bridge; clypeus rectangular; labrum triangular, 1.8X length of clypeus ( Fig. 1 ); antenna with 13 flagellomeres; scape smaller than pedicel ( Fig. 2 ); basal flagellomeres cylindrical ( Fig. 2 ); 1st flagellomere 2.1X length of 2nd flagellomere ( Fig. 2 ); ascoids lost in all specimens studied; fovea of ascoids observed in all flagellomeres, except the last; flagellomeres 3 to 13 shorter than the first and second ( Fig. 3 ); last flagellomere (13th) with small conical apiculus ( Fig. 3 ); palpus formula = 1.0:0.8:0.7:0.9 ( Fig. 4 ). Wing ( Fig. 5 ) with Sc reaching the C vein; CuA2 short, not reaching the wing margin. Male genitalia not inverted. Epandrium pilose ( Figs. 6, 10 ), with the posterior margin V-shaped in dorsal view ( Fig. 10 ); cerci long ( Fig. 10 ), 0.35X length of gonocoxite, with micropilosity and few bristles at the apex ( Figs. 6, 10 ). Gonocoxite pilose, 2.0X length of gonostylus ( Figs. 6, 8 ); gonocoxites separated on dorsal surface ( Fig. 8 ); gonocoxal apodeme triangular not fused medially ( Fig. 9 ); gonocoxites with long posterior bristle ( Figs. 6, 7, 8 ). Hypandrium lost. Gonostylus pilose with a long subterminal hair and three long, thick bristles (= spine), one of them apical, one preapical and one at middle ( Figs. 6, 7, 8 ). Sternite 10 long, triangular in dorso-ventral view, with apical micropilosity ( Fig. 10 ). Parameres pilose, complex, as drawn ( Figs. 8, 11 ); parameres linked by a subrectangular sclerotized sclerite ( Fig. 8 ). Aedeagus with one aperture ( Figs. 8, 11 ); genital filaments parallel in ventral and dorsal views ( Figs. 8, 9 ) and U-shaped in lateral view ( Fig. 11 ). Aedeagal apodeme 0.8X length of gonocoxite, narrow in dorsal view ( Figs. 8, 9 ), wide in lateral view ( Figs. 6, 11 ).

Female. Similar to males except as follows: sternite 8 fused to tergite 8 (= sintergosternite) ( Fig. 12 ); lobes of sternite 8 wider dorsally than ventrally ( Fig. 12 ). Tergite 9 wide ( Fig. 12 ). Tergite 10, subtriangular in lateral view, sclerotized, articulated to sternite 10 ( Fig. 12 ); sternite 10 between the cerci ( Fig. 12 ); cerci hemispheric in lateral view ( Fig. 12 ).

Taxonomic comments. The new species described here is morphologically similar to four other species from the Pacific slopes of the Colombian Andes that were described by Young (1979). These five species have three or more spines on the gonostylus as well as a characteristic genital filament not observed in other Neotropical species of Sycorax . Three species of Andean Sycorax have 3 spines in the gonostylus: S. colombiensis Young, 1979 ; S. fairchildi Young, 1979 ; and S. trispinosa Young, 1979 . The other species, S. andicola Young, 1979 , has 4 spines in the gonostylus. Only S. colombiensis and S. fairchildi have a gonostylus with a long subterminal bristle. The new species can be differentiated from the latter two species by the shape of the genital filaments as observed in lateral view: in S. colombiensis it is longer than the aedeagus and sinuous; in S. fairchildi it is the same length of the aedeagus and slightly curved; and in the new species it is longer than the aedeagus and U-shaped.

Among the Andean species of Sycorax , the Colombian species collected on the Pacific slopes and the new Ecuadorian species collected on the Amazonian slopes seem to belong to a unique evolutionary lineage, separated from the other species of Neotropical Sycorax . We prefer not propose a new supraspecific taxon at this time for these Andean species of Sycorax because this genus has not yet been well studied.

Biological remarks. All the specimens of the new species of Sycorax were found in contact with the dorsal surfaces of head, body and extremities of male individuals of Atelopus sp. ( Fig. 13 ). The flies were found active at night when the frogs were resting on top of leaves from vegetation adjacent to the stream. Of 1306 captures of individuals of Atelopus sp., Sycorax flies were detected on nine occasions, in April, August, September, November and December. The number of flies counted on frogs varied from 5 to 55 (mean 19 ± 17, n = 9) ( Salazar-Valenzuela 2007). One frog rubbished its back with its front and hind legs when dipterans were present, and another frog was found with its hands on top of its eyes when a high number of flies (7) were present on its head. On December 9th, 2007, 14 flies were found on a male Atelopus sp. Of these, ten were males and four were females (two with blood in their abdomen). On April 1st, 2007, 55 flies were found on another male Atelopus sp. Of these, 48 were males and seven were females (three with blood in their abdomen).

Desportes (1942) collected specimens of the European Sycorax silacea feeding on frogs’ blood of the species Rana esculenta L. (= Pelophylax lessonae x Pelophylax ridibundus, Frost 2008 ); the female flies collected were infected with filarial worms of Icosiella neglecta (Diesing) . It is known that only females of Sycorax bite, because only they possess mandibles. Our finding of blood on females of the new species of Sycorax suggests that they were feeding on harlequin frogs’ blood. The high number of male flies collected on Atelopus sp. can be interpreted as an aggregation behavior of males to mate.

It is worth noting that the biological association between flies of the genus Sycorax and harlequin frogs presented in this paper differs from parasitic associations reported between other groups of flies [blow flies ( Calliphoridae ), flesh flies ( Sarcophagidae ), grass flies ( Chloropidae ) and muscid flies ( Muscidae )] and several anuran families (see Hagman et al. 2005). In those cases, flies produce myasis –invasion of fly larvae in vertebrate tissues – which is lethal for frogs. The low frequency of encounters of S. wampukrum sp. nov. on Atelopus sp. (nine registers of over 1300 frog captures) is in agreement with the classification of Skevington (2002) of members of the family Psychodidae as transient blood-suckers, rather than true parasites. This last statement might change in the future if filarial worms are found infecting the frogs. At this time, we have not been able to examine blood contained on female flies or frogs’ blood due to scarcity of encounters with flies and the endangered status of the population of harlequin frogs monitored.

Most flies of the subfamily Sycoracinae have been collected on vegetation close to running water ( Bejarano et al. 2008), and as this is the same type of habitat associated with harlequin frogs, because they reproduce under lotic conditions ( Lötters 1996), it is quite possible that these two taxa interact in other regions of the Neotropics. Given the critical challenge of conserving these frogs, more information will be needed about their basic biology ( Lötters 2007). Ecological interactions between insects and harlequin frogs is an important area of research as previous studies have shown that these relationships can have significant consequences on individual frogs (such as lethal parasitism, Crump & Pounds 1985) or on their habitats (such as alterations in aquatic insect communities, Ranvestel et al. 2004).

Figures

FIGURE 13. Specimen of harlequin frog, Atelopus sp., from Río Napinaza, Ecuador, with specimens of Sycorax wampukrum Bravo & Salazar-Valenzuela sp. nov. on the dorsal surface of its body.

FIGURES 1 – 12. Sycorax wampukrum Bravo & Salazar-Valenzuela sp. nov., male. 1. Head. 2. Antenna: scape, pedicel and basal flagellomeres. 3. Antenna: flagellomeres 10 – 13. 4. Palpus. 5. Wing. Male terminalia, Figures 6 – 11: 6. Lateral. 7. Gonostylus and gonocoxite 8 Dorsal. 9. Ventral. 10. Epandrium, Cerci and sternite 10. 11. Aedeagus, paramere and genital filament. Female terminalia, Figure 12: 12. Lateral. (ae = aedeagus; ce = cercus; gf = genital filament; pr = paramere; S 8 = sternite 8; S 10 = sternite 10; T 8 = tergite 8; T 9 = tergite 9).