Cotesia cassina Salgado-Neto, Vasquez & Whitfield, 2021

Salgado-Neto, Geraldo, Vasquez, Consuelo Alexandra Narvaez, Max, Dillon S. & Whitfield 3, James B., 2021, Cotesia cassina sp. nov. from southwestern Colombia: a new gregarious microgastrine wasp (Hymenoptera, Braconidae) reared from the pest species Opsiphanes cassina Felder & Felder (Lepidoptera, Nymphalidae) feeding on Elaeis oil palm trees (Arecaceae), ZooKeys 1061, pp. 11-22 : 11

Cotesia cassina Salgado-Neto, Vasquez & Whitfield sp. nov.

Material examined.

Holotype Female , Colombia: Nariño, San Andrés de Tumaco (1°47'28.0"N, 78°47'33.9"W, 28 m elev.), March 2019, coll. Consuelo Vásquez, ex larva Opsiphanes cassina Felder & Felder ( Lepidoptera , Nymphalidae ). Deposited in the collection of the National University of Colombia (UNC, Dr Fernando Fernandez, curator) . Paratypes 2 males, deposited in UNC, same data as holotype . 1 female, also same data as holotype , deposited in the Illinois Natural History Survey (INHS). Non-types. 2 females, in poor condition, also deposited at INHS.

Diagnosis.

As discussed above, Cotesia is a huge worldwide genus of hundreds of species, with many morphologically similar species. While useful world identification keys are not available, it is currently possible to successfully diagnose species regionally, especially combined with molecular and host data. The closest described species, morphologically, biologically and within the region, is Cotesia invirae from southern Brazil, which also parasitizes Opsiphanes on palms (different species). The table below provides a diagnostic comparison between the two species.

Cotesia alia (Muesebeck), also recorded from Opsiphanes , resembles these two species but has a relatively longer first metasomal tergite (see illustration in Muesebeck 1958). Like C. cassina , the second tergite has the medial part of the second tergite longer than the lateral portions, and the tergites tend to both be blackish (tending to be mostly orangish in C. invirae ). The other two named Cotesia species recorded from Opsiphanes , C. biezankoi (Blanchard) and C. opsiphanis (Schrottky), are both very poorly characterized in their descriptions and their type locations are unknown ( Fernandez-Triana et al. 2020), so they are not compared here. There is a possibility that C. invirae might prove to be a junior synonym of C. biezankoi , based on shared host and geographic region, if the holotype of the latter were to resurface and be examined. Our understanding of the correct nomenclature for the entire complex would benefit from a full review of the named and putative unnamed species across all of Central and South America, especially if all the types could eventually be located. In the meantime, it is possible to characterize the relationships among the species for which we can clearly establish the identity.

Description.

Female. Body length 3.1-3.3 mm; fore wing length 2.9-3.1 mm. Coloration (Fig. 2A-F ). General body coloration black except: scape shading from light to dark brown, palps pale yellow, tegulae brown, fore legs all yellowish, middle legs all yellowish, hind legs all yellowish except distal end of femur brown/black dorsally; distal end of tibia brown, coxae translucent yellowish, laterotergites yellowish ventrally, shading to brown dorsally; sternites and hypopygium translucent yellowish. Head (Fig. 2A, E ). Facial sculpture weakly punctate; vertex sculpture smooth to very weakly punctate; distance between posterior ocellae nearly identical with distance from outer ocelli to compound eyes. Mesosoma (Fig. 2A, B, F ). Pronotum with both dorsal and ventral grooves present, ventral groove crenulate. Mesoscutum fully and distinctly but shallowly punctate; scutoscutellar scrobe slightly sunken groove and formed by 8 pits. Scutellum shield-shaped to subtriangular (anteriorly straight and posteriorly rounded) and weakly convex, weakly punctate. Mesopeuron smooth and polished throughout. Propodeum generally finely rugose/punctate with indistinct longitudinal medial carina. Legs (Fig. 2A-C ). Hind coxa mostly smooth with faint sculpture on dorsal face; inner hind tibial spurs slightly longer than outer. Wings (Fig. 2B, C ). Fore wing hyaline with dark brownish vein pigmentation; stigma more than 2 × as long as broad, without obvious pale spot at proximal end. Metacarp extending 0.60-0.70 to end of 3Rs fold along wing edge; r approximately same length as 2RS vein and meeting it at a distinct shallow angle; vannal lobe edge roughly semicircular with distal end slightly flattened; vannal lobe fringe even and dense. Metasoma (Fig. 2B-D, F ). Tergite 1 roughly as long as broad, evenly widening from anterior margin then rounding over posterior half, mostly rugulose; tergite 2 very weakly rugulose peripherally, mostly smooth and slightly raised centrally, roughly twice as broad as long, subrectangular with posterior margin slightly longer medially than laterally. Hypopygium with angled but blunt tip, not extending past dorsal end of metasoma; ovipositor with very sparse setae at tip.

Male. Similar to female except with slightly narrower metasoma.

Molecular data.

COI barcode deposited in GenBank (MW405620). Using the identification tools in the Barcode of Life Database ( Ratnasingham and Hebert 2007), C. cassina is closest to C. salebrosa (Marshall), a primarily Eurasian species attacking geometrid larvae, at a similarity level of 97.4%. Interestingly, C. invirae appears closest (97.02% similarity) to Cotesia Whitfield78 and Cotesia Whitfield20, two apparently conspecific sets of rearings of an undescribed species from the Lepidoptera Inventory of the Guanacaste Conservation Area (ACG) in northwest Costa Rica ( Janzen et al. 2009); these rearings are from another species of Opsiphanes . It thus appears that there is a complex of at least four closely related species attacking different Opsiphanes species in a variety of geographically dispersed Neotropical habitats, as suggested by Salgado-Neto et al. (2019). BOLD and NCBI use slightly different criteria to make cutoffs in sequence comparisons, and to calculate % similarity. They also contain different sets of sequences. We checked the BOLD investigations of related species by using BLASTn ( Altschul et al. 1990) to query the NCBI nucleotide database ( NCBI 1988). The same most closely related species to Cotesia cassina and C. invirae , respectively, were recovered, with the exception that for C. cassina , C. melitaearum (Wilkinson) and C. koebelei (Riley), both attacking other genera of Nymphalidae but in the Holarctic region, joined C. salebrosa as closest, at roughly 94.6-95.6% similarity for all of them. In neither the BOLD nor the NCBI search did C. cassina come within 2.5% similarity of any other known Cotesia species.

Host.

Opsiphanes cassina (Felder & Felder) ( Lepidoptera , Nymphalidae ) (Fig. 1C, D ).

Biology/ecology.

Cotesia cassina is a gregarious parasitoid wasp that occurs mainly in the wet season (March-May); however, their host, O. cassina , occurs throughout the year, mainly in the rainy season (March-July). Cotesia cassina larvae kill the host larva before the end of the last instar and form their cocoons in a regular mass of dirty whitish cocoons, regularly arranged disposed under the host (Fig. 1B ). The larvae of this gregarious species all emerge from the host in a short time through many different holes in the host cuticle and spin a common woolly cocoon mass within which the individual cocoons can be distinguished.

Distribution.

Known so far from San Andrés de Tumaco, Nariño, Colombia (Neotropical Region).

Etymology.

The specific epithet Opsiphanes cassina , is a reference to Opsiphanes cassina (Felder & Felder) ( Lepidoptera , Nymphalidae ), the host caterpillar name. The word Opsiphanes cassina is the feminine of cassino which in Italian means playhouse.

Figures

Figure 1. A simplified map of Colombia, showing rough location of Tumaco B close-up of southwestern Colombia, with location of Tumaco highlighted C caterpillar of Opsiphanes cassina on frond of the palm Elaeis oleifera x E. guineensis D same as C but with cocoons of emerged Cotesia cassina arranged below (normally underneath caterpillar).

Figure 2. Cotesia cassina, sp. nov. A lateral habitus B dorsal view of mesosoma and anterior metasomal tergites C fore wing D lateral view of metasoma with hind leg removed, showing laterotergites, sternites, hypopygium and ovipositor sheaths E frontal view of head F dorsal view of posterior portions of mesosoma, especially propodeum.