Aspidophorodon (Eoessigia) vera, Stekolshchikov, Andrey V. & Novgorodova, Tatiana A., 2010

Stekolshchikov, Andrey V. & Novgorodova, Tatiana A., 2010, A new species of Aspidophorodon Verma (Hemiptera, Aphididae) from the Altai Republic, Zootaxa 2566, pp. 39-44 : 39-43

Aspidophorodon (Eoessigia) vera sp.nov.

(Figs. 1–9)

Type material. Holotype: apterous viviparous female, No. 13085, slide No 2, specimen No 3 (right specimen in lower row), Aspidophorodon vera sp. nov., 0 2 VII 2006, the Altai Republic, Kosh–Agachsky Region, southern macroslope of the South-Chuysky Mountain Ridge, in the lower reaches of the Tara River, Pentaphylloides fruticosa (Rosaceae) on the underside of leaves along their margins. Leg. T.A. Novgorodova and V.S. Sorokina. Paratypes: 29 apterous females on 18 slides, same data as for holotype; 23 apterous females on 23 slides " Aspidophorodon vera sp. nov., No 13191, 11 VII 2009, the Altai Republic, Kosh– Agachsky Region, in the lower reaches of the Tara River, altitude of 2200 m, Pentaphylloides fruticosa , on the underside of leaves along their margins. Leg. T.A. Novgorodova ".

Etymology. The species has been named after Vera S. Sorokina in gratitude for her help in collecting the samples.

Description. Apterous viviparous female. Body elongated-eggshaped, wide in the thoracic part and gradually narrower to end of abdomen, 2.0–2.4 (2.1) times as long as wide. Light green, without slightly waxy pulverulence; siphunculi and cauda light. Cleared specimens with brown apex of base of last antennal segment, processus terminalis, and tarsi; with light-brown ultimate segment of rostrum, also apices of siphunculi and subgenital plate. Abdominal dorsum not sclerotized, light. Surface of head large-wrinkled, of dorsal side of thorax and abdominal tergites I–VI thickened, coarsely wrinkled, sometimes knobby, abdominal tergite VII slightly reticulate, of tergite VIII with large numerous scales; ventral side of thorax wrinkled, ventral side of abdomen with rows of small hardly noticeable spinules. Setae on dorsal and ventral surface of thorax and abdomen sparse, short (longest dorsal, marginal and ventral setae on abdominal tergite III 8–13 (10), 8–13 (10) and 13–25 (18) microns long, 0.35–0.71 (0.48), 0.38–0.67 (0.50) and 0.60–1.25 (0.88) times as long as articular diameter of 3rd antennal segment, respectively); setae on dorsal surface of thorax and abdomen blunt, almost rod-shaped, on ventral surface pointed; marginal setae 0–1, 0–1, 0–2, 0–1, 0–1, 0–1 and 0–2 on each side of abdominal segments I–VII; abdominal segment III with 2–5 (3.9) dorsal and marginal setae; tergite VI with 1–3 (2.0) setae between siphunculi; setae on central areas of abdominal tergites VII–VIII thick, blunt, sometimes capitate or cleft apically, on margins of these tergites pointed, tergite VIII with 5–14 (9.6) setae, 25–48 (37) microns long, 1.18–2.38 (1.82) times as long as articular diameter of 3rd antennal segment. Marginal and spinal tubercles absent. Head with weak traces of epicranial coronal suture, or without traces. Frontal tubercles clearly marked, median tubercle large, protuberant from semicircular up to almost rectangular, sometimes with rather shallow depression in the middle; median tubercle surpassing the level of antennal tubercles. Occipital setae short and blunt, frontal setae long, thick, blunt or weakly capitate, longest occipital and frontal setae 8–13 (11) and 25–35 (33) microns long, 0.35–0.71 (0.52) and 1.29–2.00 (1.61) times as long as articular diameter of 3rd antennal segment, respectively. Antennae 5-segmented due to fusion of 3rd and 4th segments. Secondary rhinaria absent. Antennae with very rare setae; 3rd antennal segment with 0–2 (0.5) setae 5–10 (8) microns long, 0.24–0.50 (0.39) times as long as articular diameter of 3rd antennal segment; base of 5th antennal segment with 0–1 (0.9) seta, 0.40–1.00 (0.62) times as long as articular diameter of basal part of the segment. Rostrum short, reaching only anterior margin of mesothorax. Ultimate rostral segment wedge-shaped with slightly concave sides, 1.58–2.06 (1.80) times as long as its basal width, with 1–3 (1.9) accessory setae. Legs short, hind femora and hind tibiae 0.13–0.18 (0.15) and 0.22–0.29 (0.25) times as long as body length, respectively. Setae on legs short, blunt, on apices of tibia blunt or pointed; ventral seta on hind trochanter 0.45–0.68 (0.56) times as long as basal diameter of hind femur; longest dorsal, ventral and dorso-apical setae on hind femur 10–20 (15), 10–25 (14) and 8–14 (11) microns long, respectively; longest dorsal seta on hind tibia 18–30 (22) microns long, 0.54–1.00 (0.74) times as long as the mid-diameter of the latter. Chaetotaxy of first tarsal segment 3, 3, 2 in 86% of individuals; in 14% of individuals one hind tarsus with 3 setae, also in 14% of individuals one fore or middle tarsus with 2 setae. 2nd segment of hind tarsus 3.56–4.50 (3.98) times as long as its maximum width and 0.81–1.31 (0.94) times as long as base of 5th antennal segment, with 3 pair of apical setae, ventral and dorsal setae absent or one ventral seta present in 4% of individuals only. Siphunculi long, thin, clavate in base and weakly expanded in apical quarter, without flanges, with the apices splay inside, slightly curved to the central line of body. Diameter of siphunculi in apical quarter 1.00–2.13 (1.44) times the smallest diameter of siphunculi. Surface of siphunculi coarsely wrinkled in the basal third, clearly scaly in middle part and smooth in apical quarter, 14.10–23.69 (17.86) times as long as its basal width, 0.18–0.24 (0.22) times as long as body length and 1.78–2.51 (2.19) times as long as length of 3rd antennal segment. Abdominal tergite VII with two small, sometimes weakly marked, wart-shaped or cone-shaped tubercles with long, thick, blunt or weakly capitate setae present in 23% of specimens, these tubercles fused in cone-shaped or more often in short finger-shaped process with two setae at apex in 77% of specimens; height of process 0.8–1.6 (1.1) times as long as width of process in base. Abdominal tergite VIII with large, clearly marked triangular or triangular finger-shaped process with 2 long, thick, blunt, weakly capitate or apically cleft setae, 2 similar setae situated at base of process; height of process 0.9–1.8 (1.4) times as long as its basal width. Weakly marked process of two small, approximate and almost fused wart-shaped tubercles with seta at apex. Subgenital plate oval, with 3–8 (5.2) pointed setae on anterior half and 2–7 (4.2) setae along the hind margin. Setae on anal plate finely pointed. Cauda tongueshaped with pointed apex and easy narrowing in first third, 1.49–2.00 (1.73) times as long as its basal width, with 5–10 (7.3) long, finely pointed setae.

FIGURIES 1–9. Aspidophorodon vera sp.nov., holotype. 1, body; 2, frons; 3, antennae; 4, ultimate segment of rostrum; 5, hind tibia; 6, hind tarsus; 7, siphunculi; 8, abdominal tergites VI–VIII; 9, cauda.

Measurements of holotype. Body 1858x 893. Antennae 526: III, 172 x15; IV, 86; V, 89+71. Hind femur, 254; hind tibia, 436. Siphunculus, 395 x20. Cauda, 174 x99 (at base) x 81 (before base).

Length of body 1543–1969 (1766)

Length of antennae 450–625 (550)

Length of antennae / length of body 0.27–0.36 (0.31)

Hind femura length 233–305 (268)

length / head width across compound eyes 0.80–0.98 (0.86)

Head width across compound eyes 291–339 (314) length of base 66–109 (95)

Last antennal length of processus terminalis 58–94 (78)

segment length of processsus terminalis / length of base 0.58–1.12 (0.83)

Ultimate length 73–89 (81)

rostral length / head width across compound eyes 0.22–0.29 (0.26)

segment length of 2nd segment of hind tarsus 0.83–0.99 (0.92) length of base of last antennal segment 0.74–1.07 (0.86)

2nd segment length 78–94 (88)

of hind tarsus length / head width across compound eyes 0.25–0.31 (0.28) length of base of last antennal segment 0.81–1.31 (0.94)

Siphunculi length 309–440 (383)

length/ width of siphunculi at half length 14.10–23.69 (17.86)

Length of cauda 157–195 (174)

Length of siphunculi / length of cauda 1.85–2.60 (2.20) Distribution. Known only from the type locality in the South-east Altai (the Altai Republic).

Biology. The apterous viviparous females were first found on 2 July 2006 on the edges of the underside of leaves of Pentaphylloides fruticosa growing at the border of larch forest on the south macroslope of the South-Chuysky Mountain Ridge in the Lower Tara. The species was subsequently collected in July 2009 from the same plant-host in the same region.

Systematic relationships. David et al. (1972) described a new genus Eoessigia and a new species Eoessigia indica from several apterous viviparous females collected on the leaves of Cotoneaster sp. ( Rosaceae ) and from an unknown plant in north-western India (Simla, Himachal Pradesh). Later, Chakrabarti (1978) described a new genus Raychaudhuriella with the only species R. myzaphoides from apterous viviparous females collected on the leaves of Salix sp. in north-western India (Manali, Himachal Pradesh). A second species, R. potentillae, was described by Chakrabarti & Maity (1984) from apterous and alate viviparous females found on Potentilla sp. again in north-western India (Rambara, Uttar Pradesh).

Chakrabarti and Medda (1989) concluded after studying type material of E. indica that R. myzaphoides and R. potentillae are synonyms of Eoessigia indica and that Raychaudhuriella is thus a synonym of Eoessigia . In the same article these authors described the fundatrix, oviparous female and male of E. indica . They pointed out that this species has a normal life cycle with host alternation: aphids migrate from Cotoneaster to Potentilla . They further suggested that the record of Salix as a host-plant was a mistake. Eastop & Hille Ris Lambers (1976) referred Aspidaphis longicauda described by Richards (1963) from leaves of Spiraea sp. from Canada (British Columbia) to the genus Eoessigia . Later, Remaudière & Remaudière (1997) suggested placing Eoessigia as subgenus of Aspidophorodon Verma , and this genus thus currently includes four species. Two species belong to subgenus Aspidophorodon : A. (A.) harvensis Verma, 1966 (type species) and A. (A.) salicis Miyazaki, 1971 . Two species belong to subgenus Eoessigia : A. (E.) indica ( David et al., 1972) and A. (E.) longicauda ( Richards, 1963) . A further species, A. sinisalicis Zhang ex Zhang et Zhong , described from Salix sp. in China ( Zhang & Zhong 1980), is a possible synonym of A. (A.) salicis Miyazaki ( Remaudière & Remaudière 1997).

The structure and shape of the siphunculi, shape of frons, presence of processes on abdominal tergites, and structure of the cuticle make it possible to refer the new species described here to Aspidophorodon (Eoessigia) .

The new species is similar to A. (E.) indica but differs from it by presence of more or less distinct processes with setae on abdominal tergite VII, and sometimes on VI [one indica has a process only on VIII tergite], by larger number of setae on anterior half of subgenital plate (3–8 but only 2 on indica ), by presence of only 2 setae on first segment of hind tarsus in most of the studied specimens ( indica has 3 setae). Besides, the new species differs from A. (E.) indica by shorter length of antennae to body length (0.27–0.36 compared to 0.36–0.49 in indica ), by smaller ratio of body length and width (1.98–2.38 compared to 2.24–3.02 in indica ), by length of siphunculi and ratio of length of siphunculi to length of 3rd antennal segment (309–440 microns and 1.78–2.51 compared to 250–330 microns and 1.33–1.88 in indica ), and also by a number of other less significant characteristics.

From A. (E.) longicauda (Richards) both the new species and A. (E.) indica differ in the longer siphunculi and shorter processus terminalis. Siphunculi of A. (E.) longicauda are shorter than the cauda, and processus terminalis is more than 1.5 times as long as base of the last antennal segment. Whereas in A. (E.) vera and A. (E.) indica the siphunculi are significantly longer than the cauda, and the processus terminalis of the last antennal segment is less than 1.5 times as long as its base.

Chakrabarti and Maity (1984) described the new genus Indotuberaphis with I. sorbi as type species, based on four apterous viviparous females and two nymphs from the undersurface of leaves of Sorbus foliolosa , at altitude 4500 m a.s.l. in North India (Hemkunt, Uttar Pradesh), 11 July 1978. These aphids have the following features: (1) short 5-segmented antennae with a short processus terminalis that is significantly shorter than the base of antennal segment V; (2) wrinkled cuticle; (3) long siphunculi broadest at base, narrow at middle and weakly expanded in apical part, with the apices skewed inside, without flange; (4) long usually paired medial processes on all thoracic and abdominal tergites, and long marginal processes on all thoracic segments and I– IV abdominal segments; (5) finger like processes on antennal tubercles that are much higher than the height of a median tubercle. All these characteristics are expressed to some extent in the species of Aspidophorodon . All species of the genus Aspidophorodon have wrinkled cuticle and similar siphunculi structure. The majority of species have short 5-segmented antennae with a short processus terminalis. A. (A.) harvensis has finger like processes on antennal tubercles, and fundatrices of A. (E.) indica have long marginal processes. Therefore the only significant difference is the presence of well developed medial processes on all tergites. However, this feature varies within Aspidophorodon . Processes are not present in species of subgenus Aspidophorodon but in subgenus Eoessigia the number of projections varies from 1–3. Moreover, the fundatrix A. (E.) indica has long marginal processes although these disappear in apterous viviparous females of the following generations. The number of processes on the abdominal tergites decreases from three in the fundatrix, to one in apterous viviparous females of the following generations, and to almost complete disappearance in oviparous females. Thus there is a trend to reduce the number of projections on the abdomen. Indotuberaphis sorbi likely keeps a number of features close to the ancestral condition. Besides, aphids found at high altitude in the beginning of June could be fundatrices that have more abdominal processes than apterous viviparous females as is known in A. (E.) indica

In view of this variation Indotuberaphis Chakrabarti & Maity should be regarded as a new synonym of Aspidophorodon (Eoessigia) , and Indotuberaphis sorbi Chakrabarti & Maity should be referred to as Aspidophorodon (Eoessigia) sorbi (Chakrabarti & Maity) (comb.n.).