Delfinoia peruviana (Essig, 1953) Essig, 1953

Nafria, Juan M. Nieto, Durante, M. Pilar Mier & Ciruelos, Sara I. Lopez, 2017, Delfinoia, a new South American aphid genus (Hemiptera, Aphididae, Macrosiphini) on Cayaponia (Cucurbitaceae), ZooKeys 671, pp. 49-60 : 52-57

Delfinoia peruviana (Essig, 1953) comb. n. Figs 2A, C, 3, 4

Amphorophora peruviana Essig: Essig, 1953; Proceedings of the California Academy of Sciences, Fourth Series, 28 (3): 133 & 135.

Wahlgreniella australis Delfino: Delfino, 1981; Revista de la Sociedad Entomológica Argentina, 40 (1-4): 183-186; syn. n.

Utamphorophora peruviana (Essig, 1953): Eastop, 1997; in Remaudière (G.) & Remaudière (M.), Catalogue des Aphididae du monde / Catalogue of the World’s Aphididae ( Homoptera Aphidoidea): page 158.

Description.

Apterous viviparous females (redescription, from 30 studied specimens [see "Materials and methods"] and original descriptions of both nominal species).

Colour unknown when alive, possibly green or light green, and perhaps, from Essig’s drawing, with two small dark spots on each side of several abdominal segments, brown cauda and dark brown or blackish brown siphunculi. When mounted variably light yellow, with head, including antennae and rostrum, legs, siphunculi, anal plate and cauda more or less pigmented (see below). Quantitative characters are in Table 1. Head. Brownish yellow. Frons sinuated, with broadly divergent and moderately developed frontolateral tubercles and low frontomedial tubercle. Dorsum smooth and ventrum with stretch marks. Setae of first and second dorsal row (each with two setae) and internal setae of third dorsal row (with four setae) similar in length to each other; external setae of third row approximately half as long as the other six. These eight dorsocephalic setae, the frontolateral apical setae and the three ventrolateral setae on each side (near the margins of the antennal alveoli) have truncate apices; other ventral setae, including those on clypeus and on mandibular and maxillar laminae, are pointed. Antennal segment I slightly pigmented and mostly smooth, with its inner side somewhat darker and gently scabrous; segment II also slightly pigmented, dorsally smooth and ventrally scabrous. Antennal segment III also pale, with a smoky apical ring, and tenuous cuticular ornamentation, which is more marked on the ventral face of its 1/5 proximal portion. Its subarticular constriction is less marked than in some other aphids; possibly the antennal flagellum has reduced mobility with respect to the pedicel as a result of this structural feature. Antennal segment IV softly imbricated and mostly pale, with smoky small proximal ring and distal portion; segment V similar to segment IV but more intensely imbricated and with a longer and more pigmented distal portion. Antennal segment VI brown and imbricated. Several setae on segment VI are pointed and longer than other antennal setae, which are similar in shape and size to dorsocephalic ones. Secondary sensoria absent. Primary sensoria on antennal segments V and VI with thick, sclerotic and non-ciliate margins. Satellite sensoria grouped ventrad to the primary sensorium. Rostrum extends back to slightly beyond hind coxae. Penultimate and ultimate rostral segments similar in length and colour (light brown) and bearing many robust, rigid and pointed setae. Thorax. Paler than head and generally devoid of marked cuticular ornamentation. Spiracular sclerites rugose and unpigmented, spiracular apertures circular or subcircular. Marginal papillae on prothorax if present are small, flat and unpigmented. Both dorsal and ventral setae similar in shape and size to those on anterior abdominal segments. Tarsi and apex of tibiae pale brown, rest of legs brownish yellow. Setae on femora and most of those on tibiae short and with truncate apices; setae on coxae (which are longer than others), trochanters and tarsi pointed, as also are dorsoapical tibial setae. First segments of tarsi with three setae. Abdomen. In general paler than head. Spiracular sclerites and apertures similar to those on thorax. Intersegmental sclerites inconspicuous. Small presiphuncular sclerites small, postsiphuncular sclerites relatively wide, and a narrow transverse stripe on segment VIII; all of these sclerites spinuled and pale yellow. Dorsal setae short and with truncate apices, except those on abdominal segment VIII, which are pointed. Ventral setae pointed. One specimen (paratype) has one marginal tubercle on abdominal segment IV, small and pale. Siphunculi light brown, swollen over distal half of length, smooth or nearly smooth for most of length, and with three or four complete or incomplete circular lines below the flange, which is protruding and relatively thick. Genital plate very pale; anal plate with similar pigmentation to cauda, which is triangular with blunt apex. Setae on these plates and cauda pointed.

Alate viviparous females (redescription, from 12 studied specimens [see "Materials and methods" section] and from original descriptions of both nominal species). Fig. 2B, D.

Colour unknown when alive, possibly with dark brown or black head and thorax, including antennae and legs, and green abdomen with dark brown lateral spots, cauda and siphunculi. Quantitative characters are in Table 1; qualitative characters like those of apterae are not mentioned. Head. Brown with darker areola around each ocellus. Dorsum with tenuous ornamentation. Frontolateral tubercles very low and frontomedial tubercle inconspicuous. Antennae homogeneously brown. Antennal segment III with secondary sensoria, which are similar in shape to the primary ones and variable in size, more-or-less aligned over almost the entire length. Thorax. Legs brown, with paler coxae, trochanters and proximal part of femora. Fore wings with veins well-marked and the cubital veins dark-bordered; hind wings veins also well-marked but not bor dered. Abdomen. Pale in general. Sclerites variably pigmented, sometimes as pale as the rest of the abdominal cuticle. Intersegmental sclerites smooth. Marginal sclerites on segments I - VII spinuled, the postsiphuncular sclerites being wider than the others. Setiferous spinal and pleural sclerites present on segment VIII and sometimes on segments VI and VII, all of them spinuled and usually pale or very pale. One specimen (holotype) has four small, ill-defined and pale marginal tubercles on abdominal segments II, III (on both sides) and IV; another specimen (paratype) also has similar tubercles on one side of abdominal segments III and IV.

Males (from one specimen, see "Materials and methods" section). Fig. 2 E–F. Winged; similar to alate viviparous females in general aspect, pattern of sclerotisation, extent of pigmentation and cuticular ornamentation. Colour when alive unknown. Secondary sensoria present on antennal segments III, IV and V. Hind wings have a single oblique vein, which could well be an anomaly, although the presence of an identical anomaly in both wings is strange. Two small pale abdominal marginal tubercles present. Parameres broad, curved back, very dark brown and provided with many, rigid, pointed and relatively long hairs. Quantitative characters are in Table 1.

Biology.

It is certain that Delfinoia peruviana feeds on plants of one or more species of Cayaponia in Argentina, and perhaps also in Peru (see “Introduction”). The species has been also caught on a cruciferous plant in Cordoba (Argentina). The collector of those specimens, L. Bahamondes, was an experienced (but now deceased) entomologist and a connoisseur of Argentinean flora, so one can be certain that the specimens were collected on a plant of family Brassicaceae , but it is also conceivable that the specimens collected had fallen from some vine of the genus Cayaponia .

Distribution.

The species is currently known in two localities (one in Peru and the other in Argentina) that are 2,200 kilometers distant from each other. Possibly the species can be found in much of northern Argentina, southern Peru and also in eastern Bolivia and southwestern Brazil.