Aphis aquilonalis Stekolshchikov & Khruleva, 2015, sp. nov.

Aphis aquilonalis sp. nov.

(Figs. 2–18, Tabl. 1)

Type material. Holotype: apterous viviparous female, No. 10270, slide No. 19, “ Aphis aquilonalis sp. nov., Chukotka Autonomous Okrug, Anadyrskiy District, 40 km SSW vill. Beringovskiy, N 62° 43', E 178° 56', Rumex arcticus Trautv., 28.vii.2012, on lower side of leaves and between flowers and fruits, coll. A.V. Stekolshchikov”. Paratypes: 1 fund, 42 apt., 27 males and 100 ovip., No. 10270, from the same locality and the same data as holotype; 1 al., No. 10270, reared on 31.vii.2012 from alatoid nymphs from the same locality as the holotype, transferred to plants in laboratory conditions.

Etymology. The name aquilonalis is an adjective and derived from the Latin word “ aquilonalis ” (=northern).

Description. Fundatrix. Body broadly elliptical, 1.5 times as long as its width. Colour of living specimens unknown. Thorax and abdominal dorsum with sclerotized bands and marginal sclerites on all segments, but sometimes they are relatively weakly sclerotised; bands on abdominal tergites I–VI often interrupted in the midline. Antennae 6-segmented, or 5-segmented as a result of fusing of 3rd and 4th segments. Arms of mesosternal furca separated. Chaetotaxy of first tarsal segments 3, 3, 2 or 3, 2, 2. Cauda elongate triangular.

Apterous viviparous female. Body broadly elliptical, 1.4–1.6 (1.5) times as long as its width. The living specimens dark brown, almost black, or dark dirty yellowish-brown, with sparse waxy pulverulence on dorsal and ventral sides or only on ventral side; antennae dark with pale base of 3rd segment; fore femora light-grey with pale bases and black apices; middle and hind femora dark with pale bases; tibiae pale with dark apices; tarsi, siphunculi, and cauda dark. Cleared specimens with dark brown intersegmental plates on abdomen, siphunculi, anal plate and cauda; with head, 1st and 2nd antennal segments, 3rd segment of rostrum, coxae of all legs, trochanters and femora of middle and hind legs (except for bases), apices of tibiae, tarsi, sclerites and bands on thorax and abdomen, and subgenital plate brown; apex of 3rd antennal segment, 4th-6th antennal segments, trochanters and dorsal part of fore femora light-brown. Thorax and abdominal dorsum with sclerotized bands and marginal sclerites on all segments; bands on pro- and mesothorax and on abdominal tergite VI very large and always fused with marginal sclerites, bands on metathorax and abdominal tergites I–V relatively short, sometimes interrupted in the midline and very rare divided into separate sclerites; marginal sclerites relatively large on pro- and mesothorax and segments II–IV, and small on metathorax and abdominal segments I and V–VII; marginal sclerites and band on segment VII sometimes fused. Surface of head, dorsal and ventral sides of thorax, abdominal tergites I–VI and anterior half of abdominal sternite I reticulate, contour of cells consist from very large fused rounded spinules forming high “wall” around the cell; the reticulation on head is well marked only on occiput, on other parts of the head contours of cells are indistinct, reticulation on thorax and abdominal tergites I–VI very well marked; surface of abdominal tergite VII with the long rows of small pointed spinules, which on tergites VIII partially fuse to form scales; surface of ventral side of abdomen (exept anterior half of sternite I) with long rows of small pointed spinules sometimes forming strongly stretched reticulate cells. Setae on dorsal surface of thorax and abdomen blunt or pointed, on ventral surface finely pointed; on abdominal tergites I–IV two pairs of spinal setae: the pair situated nearer to the body margin relatively long up to 20–30 Μm, the pair situated nearer to the central line of body very short up to 10 Μm with very small base, sometimes almost invisible; numbers of marginal setae 1–2, 1–4, 2–5, 1–4, 1–4, 1–3 and 0–3 on each side of abdominal segments I–VII, respectively. Marginal tubercles present only on prothorax in 23% of specimens and very rarely paired (only 2% of specimens) and 1 tubercle present in 2% of specimens on abdominal segments I, on all other segments of body marginal tubercles absent. Marginal tubercles small (with basal diameter only 9–18 Μm), strongly protuberant from semicircular up to papilliform or elongated cone-shaped, diameter of tubercles 0.7–1.8 times as long as high. Spinal tubercles absent. Head with epicranial coronal suture or with traces of epicranial coronal suture. Frontal tubercles distinct but not well developed; antennal tubercles relatively high, median tubercle very broad and low. Occipital setae on head blunt, frontal setae blunt or pointed, setae on ventral side of head—pointed or finely pointed. Antennae 6-segmented, 1st and 2nd antennal segments slightly wrinkled, almost smooth, 2nd segments with small scales on inner side, 3rd–6th segments with large scales. Antenna without secondary rhinaria. Setae on antennae pointed or finely pointed. Rostrum reaching mesothorax. Ultimate rostral segment elongate wedge-shaped with straight or slightly concave sides, 1.80–2.40 (2.18) times as long as its basal width. Legs normal, setae on legs pointed or finely pointed or rarely simply pointed. Chaetotaxy of first tarsal segments 3, 3, 2 on most specimens, only one specimen has 3 setae on one hind leg, two specimen have 2 setae on one middle leg and one specimen have 2 setae on both middle legs. Arms of mesosternal furca connected by wide base. Spiracles reniform. Siphunculi cylindrical, slightly narrowed at base, coarsely imbricate and with very small, almost unnoticeable flange. Subgenital plate oval, setae on subgenital and anal plate finely pointed. Cauda elongate triangular or triangular finger-shaped with rounded apex and long finely pointed setae.

Measurements of holotype. Body—2426×1624, antenna—1378: III—349×38 (in the middle), IV—250, V— 190, VI—149+245; hind femur—609, hind tibia—944; siphunculus—182×61 (in the middle); cauda—202×192 (at base) ×154 (before base). For more biometric data see Table 1.

Alate viviparous female. Body egg-shaped, 1.9 times as long as its width. The living specimen yellowishbrown with dark head and thorax, without waxy pulverulence; colour of other body parts as in apterous viviparous female. Cleared specimen with drak brown head, thorax, siphunculi, anal plate and cauda; 1st and 2nd antennal segments, 3rd segment of rostrum, coxae of all legs, trochanters and femora of middle and hind legs (except for bases), apices of tibiae, tarsi, sclerites and bands on abdomen, and subgenital plate brown; 3rd–6th antennal segments, trochanters and dorsal part of fore femora light-brown. Abdomen with bands on tergites I–VIII, small marginal sclerites on I and VII, and large marginal sclerites on segments II–VI; marginal sclerites and bands on segments VI–VII fused. Surface of head, dorsal and ventral side of thorax smooth or slightly wrinkled; surface of abdominal tergites I–V indistinctly reticulate, contour of reticulate cells forming by very flat large spinules; abdominal tergite VI with sparse rows of smooth spinules situated on the contour of reticulate cells; tergite VII with rows of smooth spinules which on tergite VIII partially fuse to form short scales; marginal sclerites on segments II– VI with sparse rows of large pointed spinules sometimes situated on the contour of reticulate cells; ventral side of abdomen with long rows of small pointed spinules forming strongly stretched reticulate cells. Head with weak trace of epicranial coronal suture. Third antennal segment with 9–10 secondary rhinaria, 4th segment with 0–2 secondary rhinaria and 5th segment without rhinaria. Secondary rhinaria are round or oval, often large (with internal diameter 10–20 Μm), weakly protruberant. Ultimate rostral segment 2.57 times as long as its basal width. Cauda elongate triangular with pointed apex.

Male. Apterous. Body elliptical, 1.7–1.9 (1.8) times as long as its width. The living specimens dark dirty yellowish-brown, with very sparse waxy pulverulence; colour of other body parts as in apterous viviparous female, but antennae entirely dark. Cleared specimens with brown head, antennae, 3rd segment of rostrum, coxae of all legs, trochanters and femora of middle and hind legs (except for bases), siphunculi, anal plate and cauda; apices of tibiae, tarsi, sclerites and bands on thorax and abdomen, trochanters and dorsal part of fore femora light-brown. Sclerotized bands on metathorax and abdominal tergites I–VIII always interrupted in the midline and on abdominal tergites I–VII often divided into separate sclerites; marginal sclerites on segments II–IV relatively small. Surface of head and prothorax almost smooth, with very indistinct reticulation. One marginal tubercle present only on prothorax in 11% of specimens, on all other segments of body marginal tubercles, as well as spinal tubercles absent. Antennae 5-segmented due to partial or complete fusing of 3rd and 4th segments, or rarely specimen has one antenna 6-segmented and the other 5-segmented. Third antennal segment with 8–27 (17.4) secondary rhinaria of very different sizes (from 8 to 25 mΜ), 4th segment (for 6-segmented antennae) with 6–8 (7.0) secondary rhinaria and 5th segment with 3–10 (6.0) rhinaria. Rostrum reaching mesothorax. Cauda elongate triangular or elongate triangular with rounded or pointed apex. Hind tibiae slightly swollen on basal half, with 0–10 (3.0) round pheromone plates, more of them located on the basal half.

Oviparous female. Body broadly elliptical, 1.3–1.6 (1.5) times as long as its width. The living specimens dark brown, almost black, or dark dirty yellowish-brown, with sparse waxy pulverulence on dorsal and ventral sides or only on ventral side; antennae dark with pale base of 3rd segment; fore femora light-grey with pale bases and black apices; middle and hind femora dark with pale bases; tibiae pale with dark apices; tarsi, siphunculi, and cauda dark. Sclerotized bands on metathorax and abdominal tergites I–VIII always interrupted in the midline and on abdominal tergites I–VII often divided into separate sclerites. Marginal tubercles present only on prothorax in 26% of specimens and very rarely are paired (only 4% of specimens), on all other segments of body marginal tubercles absent. Subgenital plate oval, monotonously sclerotized, partially divided into two lobes. Cauda triangular or elongate triangular with broadly rounded apex. Hind tibiae not greatly swollen on basal half, with 5–30 (13.8) round pheromone plates, more of them located on the basal half.

Distribution. Known only from the type locality—Chukotka AO, Anadyrskiy District, 40 km SSWBer.

Biology. Monoecious, holocyclic. Colonies (one of them very large) of this species consisting of old fundatrices, apterous viviparous females, males, oviparous females, apteroid and alatoid nymphs were found on 28 July 2012, on undersides of leaves and on apices of shoots between flowers and fruits, on several plants of Rumex arcticus. Some leaves inhabited by aphids were slightly curled. Immatures were transferred to plants in laboratory conditions, where one alate viviparous female was reared.

Systematic relationships. This species has the characters typical for the genus Aphis: low frontal tubercles, simple hairs on all body and appendages, dorsal surface of body with reticulation, relatively short antennae with a relatively short processus terminalis, elongate wedge-shaped ultimate segment of rostrum, simple legs with chaetotaxy of first tarsal segments 3, 3, 2, cylindrical siphunculi and elongate triangular or triangular finger-shaped cauda. However new species is very easy to distinguish from any other known species of Aphis except A. beringiensis sp. nov. by the almost complete lack of marginal tubercles on abdominal segment I and the complete lack of marginal tubercles on segment VII. Differences from Aphis beringiensis sp. nov. are given below after its description.

The monotypical genus Misturaphis Robinson, 1967 also lacks marginal tubercles on abdominal tergites I or VII, but apterous and alate viviparae of Misturaphis have 5-segmented antennae (Aphis aquilonalis— 6- segmented), 2 setae on all first tarsal segments (Aphis aquilonalis— 3, 3, 2) and setae of apterous and alate viviparae of Misturaphis on head and antennae are comparatively long and spear-shaped (setae of Aphis aquilonalis relatively short and pointed or finely pointed).

Alate viviparous female Number of samples / specimens 3/5

Length of body 1878–2071 (1908–1971) Length of antenna 1008–1145 (1017–1085) Length of antenna / length of body 0.53–0.57 (0.55) HFem length 421–482 (424–472) length / length of body 0.22–0.25 (0.24) length / W Head 1.02–1.10 (1.07) HTib length 802–914 (807–881)

length / length of body 0.42–0.46 (0.44) W Head 412–463 (412–443) Setae on head occipital length 38–43 (40)

length / Ant3 AD 2.14–2.83 (2.14–2.83)

frontal length 38–43 (40)

length / Ant3 AD 2.14–2.83 (2.14–2.83) length on Ant 1 28–35 (31)

on Ant3 number 6–11 (7.8)

length 20–28 (24)

length / Ant3 AD 1.14–1.57 (1.32–1.44) on AntLB number 2–4 (2.5–3.0)

length / AntLB AD 1.17–1.60 (1.25–1.38) length of ventral seta on HTr / BD HFem 0.72–0.97 (0.78–0.89) on HFem length of dorsal 35–48 (43)

longest ventral 38–46 (42)

dorso-apical 25–43 (28–35) on HTib longest dorsal 46–58 (52)

longest dorsal / mid-diameter of HTib 1.33–1.67 (1.52) number on 2HT dorsal 0–2 (0.5–1.0)

ventral 1–2 (1.0–1.5)

on TerIII number of spinal and marginal 6–7 (6.2)

spinal length 30–51 (38)

length / Ant3 AD 1.71–3.08 (2.14–2.50)

marginal length 41–51 (47)

length / Ant3 AD 2.29–3.08 (2.29–2.95)

ventral length 41–51 (47)

length / Ant3 AD 2.57–3.08 (2.67–2.89) number on TerVI between siphunculi 2

on TerVIII number 2–3 (2.0–2.3)

length 46–63 (46–55)

length / Ant3 AD 2.71–3.85 (2.71–3.24) number on on anterior half 2–3 (2.0–3.0) subgenital along the hind margin 11–14 (11.7–14.0) plate

......continued on the next page AntL AntLB 106–139 (123–134) PT 152–180 (157–177) PT / AntLB 1.09–1.64 (1.18–1.41)

URS number of accessory setae 2–3 (2.0–3.0)

length 111–124 (111–122) length / W Head 0.26–0.29 (0.27) 2HT 0.95–1.20 (0.97–1.08) AntLB 0.85–1.14 (0.89–0.98)

2HT length 101–123 (114) length / maximum width 4.44–5.22 (4.89) W Head 0.24–0.28 (0.26) AntLB 0.58–0.73 (0.67)

SIPH length 132–152 (134–146)

length / length of body 0.07–0.08 (0.07) length / BW SIPH 2.52–4.07 (3.02) length / MW SIPH 3.25–4.14 (3.43–3.99) length / Ant3 0.48–0.56 (0.52)

CAUD length 182–197 (182–194) length / BW CAUD 1.23–1.53 (1.38–1.50) number of setae 9–15 (9.0–15.0)

Length of SIPH / length of CAUD 0.72–0.77 (0.75)