Grotea coca, Ramello & Aquino & Lucia, 2025

Grotea coca sp. nov. Ramello, Aquino & Lucia

urn:lsid:zoobank.org:act:F399C138-6511-4D5E-BA0A-B394FF9B1652

( Figs. 1 View FIGURE 1 and 2 View FIGURE 2 )

Diagnosis. This species differs from others within the genus by the following combination of characters: head in dorsal view with gena concave behind eyes; postgenal process evident, laterally distinct forming a straight angle anteriorly and slightly curved posteriorly; antenna with 55 flagellomeres; pronotum neck with a rounded carinae in anterior third; general body colour red amber, with orange yellowish tibiae and pro and mesotarsi; mesosoma 3.17× as long as high; metasoma with contrasting brown tergites and yellow sternites with three light brown transversal lines.

Holotype. ARGENTINA: ♀, Buenos Aires, La Plata, Parque Sicardi , 2-6.iii.2023, Coll. P. Ramello ( MLP).

Paratypes. (n = 3) 1 ♀ 2 ♂, same data as holotype ( MLP) .

Description. Holotype. Female. Body length 18.0 mm ( Fig. 1a View FIGURE 1 ).

Head. Head in dorsal view with gena rounded behind eye, occiput pubescent. Posterior ocellus separated from the eye 2.54× its own diameter. Supra-clypeal area with small piliferous punctures and shiny. Fronto-clypeal suture strong and arched ( Fig. 1b View FIGURE 1 ). Eyes slightly convergent below. Clypeus 2.9× as wide as long. Occipital carina rounded dorsally. Gena at junction with hypostomal carina forming an acute angle ( Fig. 1c View FIGURE 1 ). Antenna with 55 flagellomeres. First flagellomere 0.9× as long as combined length of second to fourth flagellomeres. Mesosoma. Mesosoma 3.17× as long as high, polished and almost entirely impunctate. Pronotum in lateral view with a rounded carinae in anterior third ( Fig. 1c View FIGURE 1 ); pronotal scrobe absent. Epomia absent. Scuto-scutellar groove deeply impressed and scutellum distinctly convex. Propodeum with area basalis, about 1.2× as long as wide, posteriorly open, anterior transverse carina medially incomplete; spiracles in lateral view almost straight line shaped; pleural carina distinct only anteriorly to anterior transverse carina; longitudinal medial carina do not reach the posterior segment of propodeum, with the second pleural area of propodeum 1.6× as long as wide (second pleural area of propodeum closed) ( Fig. 1d View FIGURE 1 ); posterior transverse carina absent. Forewing length 11.1 mm. Wings hyaline, pterostigma brown. Areolet large and pentagonal, about 2.0× as wide as long. Hind wing with eight (8) basal hamuli on RS. Metasoma. Tergite 1 very long, 0.78× as long as mesosoma. Exposed portion of ovipositor 5.0 mm, about 1.28× as long as hind tibia.

Colouration ( Figs1a–d View FIGURE 1 ).Head orange to brown,frons irregularly coloured varying from yellow to orange; occiput almost brown; scape orange with yellowish apex, pedicel and firsts antennal flagellum bicoloured, orange ventrally and brown dorsally; rest of flagellum brown to dark brown. Pronotum, mesoscutum, scutellum, postscutellum, propodeum, meso and metapleura red amber. Fore and mid legs with coxae and femurs light orange, tibiae and basal tarsi yellow, other tarsal segments brown basally and yellow distally; hind legs with coxa, trochanter, femur and base of tibia red amber; trochantellus, apex of tibia and basal tarsi yellow; second tarsomere basally brown and yellow at apex; 3rd–5th tarsomeres brown. Wings hyaline. Metasoma with first tergite red amber; remaining terga brown; metasomal sternites yellowish; ovipositor almost entirely yellow with apex red; ovipositor sheaths brown.

Description. Male. Similar to females in length and colour. Measurements of paratype: body length: 18.0 mm; mesosoma: 5.0 mm; metasoma: 11.5 mm. Head width 2.3 mm, 1.64 mm high; forewing length 10.3 mm. Head frontal 0.7× as high as wide; antenna with 50 antennomeres, mesosoma 2.0× as long as high, first metasomal tergite 0.78× as long as mesosoma.

Etymology. The specific epithet is a matronym honouring Mrs. Ángela Inés Panario, (warmly called “Coca”) who was Ramello´s grandmother, a dear person and nature enthusiast.

Distribution. Grotea coca sp. nov. is known from the Buenos Aires province in Argentina ( Fig. 2 View FIGURE 2 ).

Biological notes. A total of 16 nests of Ceratina rupestris were found in vertical stems of Dipsacus fullonum L. ( Dipsacaceae ) in the study area ( Fig. 3 View FIGURE 3 ). Adult parasitoids of Grotea coca sp. nov. emerged from four of these nests between 2 and 6 March 2023. Nest 1 contained four pupae and three adults (both females and males) of bees, from this nest a female Grotea emerged on March, 2023. The dimensions of the G. coca cocoon were 2.79 cm in length and 4.75 mm in maximum diameter. Additionally, it was observed that the cocoon occupied approximately two host cells. Nest 2 contained six dead larvae, one pupa, one female of C. rupestris , and a female of Grotea emerged from this nest. The cocoon dimensions were 3.43 cm in length and 5.43 mm in maximum diameter, occupying three host cells. Nest 3 contained six dead larvae, three pupae, one female, one male of C. rupestris , and a male of Grotea emerged from this nest, with cocoon dimensions of 3.93 cm in length and 5.0 mm in maximum diameter, occupying the dimension of three host cells. Lastly, Nest 4 contained one dead larva, three pupae, one female of C. rupestris , and a male Grotea emerged from it, with cocoon dimensions of 2.7 cm in length and 4.25 mm in maximum diameter, occupying approximately three host cells.

The post-feeding larva of Grotea builds a cocoon in the nest space previously occupied by two or three cells of the host. The white cocoon is initially applied to the nest wall as a thin, cellophane-like layer. However, it thickens and becomes stiffer at each end, forming a septum which spans the diameter of the nest. Additionally, a deposit of faeces was found inside the cocoon's lower septum ( Fig. 3c View FIGURE 3 ). The cocoons occupy the space among host breeding cells at the top, causing the brood cells to be displaced to the bottom. From the nest entrance to the cocoon structure, all larvae continue their development.

Remarks: Grotea coca sp. nov. does not fit the description of any species previously outlined in the keys of Slobodchikoff (1970) or Gauld (2000), nor does it correspond to species described later by Herrera-Florez (2014, 2018), Herrera-Florez & Penteado-Dias (2019), Sandoval & Santos (2021), Lima & Kumagai (2024), or Mazón et al. (2024). For this reason, we believe it is important to construct a key for the identification of Grotea species present in Argentina. For this, specimens deposited in the collections of the IADIZA and MLP were studied. Additionally, localities cited by Porter (1982) and Slobodchikoff (1970) were included.

Material studied:

Grotea gayi (Spinola) : ARGENTINA. 1♀, Neuquén, San Martin de los Andes (640 M. S.N.M), 15.ii.1980, Lg. M. Gentili, ( IADIZA) 2009, Ex. Coll. M. Gentili; 1♀, Neuquen, San Martin de los Andes (640 M. S.N.M), 30.i.1981, Lg. M. Gentili, ( IADIZA) 2009, Ex. Coll. M. Gentili.

G. superba (Schmiedeknecht) : ARGENTINA. 1♀, Neuquén, San Martin de los Andes (640 M. S.N.M), 30.i.1981, Lg. M. Gentili, ( IADIZA) 2009, Ex. Coll. M. Gentili; 1♀, Neuquén, Pucará , 20.iii.1971, Lg. Schajovskoi ( IADIZA) 2009, Ex. Coll. M. Gentili. 3♀, Pucará, Parque Nacional Lanin , ii.1951, Lg. J. Schajovskoi, Porter det. ( MLP)

G. cortesi ( Porter, 1989) : ARGENTINA. 1♀, Neuquén, Pucará , 20.iii.1971, Lg. Schajovskoi ( IADIZA) 2009, Ex. Coll. M. Gentili.

G. eburnea ( Porter, 1989) : ARGENTINA. 1♀, Neuquén, San Martin de los Andes (640 M. S.N.M), 10.i.1981, Lg. M. Gentili, ( IADIZA) 2009, Ex. Coll. M. Gentili. New record.

G. delicator (Thunberg) : ARGENTINA. 1♀, Buenos Aires, Magdalena , xii.1965, Col. Townes ( MLP).