Hyperomyzus (Neonasonovia) nigricornis ( Knowlton, 1927 )

Nieto Nafría, Juan M., Hidalgo, Nicolás Pérez, García-Tejero, Sergio, López Ciruelos, Sara I. & Durante, M. Pilar Mier, 2017, Contribution to the knowledge of North-American species Hyperomyzus subgenus Neonasonovia (Aphididae, Aphidinae, Macrosiphini), Zootaxa 4294 (2), pp. 241-255 : 246-247

Hyperomyzus (Neonasonovia) nigricornis ( Knowlton, 1927)

Amphorophora nigricornis was described by Knowlton (1927: 185) and it was transferred to Hyperomyzus (in the subgenus Neonasonovia ) by Eastop & Hille Ris Lambers (1976: 121). The alate fundatrigenia (on Ribes , its primary host) was the only morph originally described; Blackman & Eastop (2016) noted that specimens of this species caught on Hieracium and Picris , probably secondary hosts, are conserved in the Natural History Museum collection. They have ornamented siphunculi. The species is known in Utah and perhaps Oregon ( United States).

Studied specimens. United States: Idaho, Emida, on Hieracium or Picris species, and swept, 15-VII-1998, J.H. Martin leg. & det., respectively 9 apt & 3 al, and 1 apt; Cub River Canyon, sweeps of Rudbeckia , 15-VII-1958, Knowlton leg. & det., 1 al; Utah, Logan Canyon, light trap, 9-IX-1956, Knowlton & Collmar leg., Knowlton det., 1 al, and on Ribes sp., 4-VII-65, Knowlton leg., Hille Ris Lambers det., 1 al; Washington, Kittitas, on Ribes sp., 6- VI-1996, Pike leg., Remaudière det., 1 apt & 2 al; Klickitat, on Madia minima , V-1996, Pike leg., Remaudière det., 4 apt; Pierce, on Senecio sp., 8-X-1995, Pike leg., Remaudière det., 2 apt; Yakima, on Ribes aureum , 30-V-1996, Pike leg., Remaudière det., 6 apt & 4 al; specimens from Idaho and Utah in the Natural History Museum, and specimens from Washington in the Muséum national d’Histoire naturelle.

Alate viviparae from primary host ( Figure 2 A), complementary data. Descriptions of qualitative features are unnecessary, because previous descriptions are complete, and differences have not been observed in the studied specimens. Quantitative characteristics in table 2.

Alate viviparae from secondary host ( Figure 2 B), description from 5 specimens. Head brown to dark brown, as dark as thorax, and with smooth dorsum. Antennae dark brown, with most proximal portion of segment III paler. Antennal segment I nearly smooth, segment II and proximal portion of segment III with scales, rest of antenna more or less imbricate. Coxae, trochanters and proximal half of femora pale; distal half of femora, tibiae and tarsi dark brown. Marginal sclerites on abdominal segments 2 to 5 and transverse spinopleural bands on segments 7 and 8, sometimes pale-brown; other abdominal sclerites (setiferous and postsiphuncular) always pale. Siphunculi very poorly inflated, peduncle pale and rough with swollen part smoky and bearing scales. Genital plate pale; anal plate and cauda as dark as darkest part of siphunculi. Quantitative characteristics in table 1.

Apterous viviparous females, fundatrigeniae ( Figure 2 C), description from 7 specimens. Body completely pale, excepting: the pre- and postarticular areas of antennal segments III to VI, the area occupied with the sensoria (primary and satellites) of antennal segment VI, the distal half of the terminal process, a small distal portion of the tibiae and sometimes a distal dorsal mark on femora. Most proximal part of antennal segment III with fine spinules and segments V and VI with fine imbrication; other antennal segments smooth. In all other aspects, they are similar to the virginogeniae. Quantitative characteristics in table 1.

Apterous viviparous females, virginogeniae ( Figure 2 D), description from 17 specimens. Dorsum of head yellowish-brown or pale-brown, smooth or weakly striate. Antennal segments I and II nearly smooth and darker than the dorsum of the head; segment III mostly as previous segments, paler on proximal part and darker to distal end; segments IV and V tenuously imbricate, and pigmented near articulations; segment VI dark-brown. Coxae, trochanters and proximal half of femora light-brown, two thirds of tibiae pale-brown, and distal part of femora and tibiae as dark as tarsi. Dorsum of thorax and abdomen with setiferous (slightly raised and somewhat striate) and postsiphuncular sclerites plus individual transverse bands on segments 7 and 8, all of them usually unpigmented. Siphunculi scarcely swollen (see table 1) with distal half as dark as distal half of femora, with spinules and scales on entire length, particularly in two distal thirds. Cauda and anal plate as pigmented as distal part of siphunculi, the former bearing setae on entire length. Quantitative characteristics in table 1.

Comments. The heteroecious life cycle of this species is confirmed; secondary host species could be species of Madia , Picris or Hieracium , Rudbeckia and Senecio based on collectors’ data. The species is recorded for the first time from Idaho and Washington.

Figures

FIGURE 2. Hyperomyzus (Neonasonovia) nigricornis; A, alate fundatrigenia (living on Ribes); B, alate virginogenia (living on Picris); C, apterous fundatrigenia (living on Ribes); D, apterous viviparous females (living on Picris). Scale bar: 1 mm.