Macromyzus spinosus, Su, Xiao-Mei & Qiao, Ge-Xia, 2010

Su, Xiao-Mei & Qiao, Ge-Xia, 2010, Macromyzus Takahashi (Hemiptera, Aphididae), a generic account, description of one new species, and keys to species, Zootaxa 2619, pp. 1-13 : 3-8

Macromyzus spinosus sp. nov.

( Table 1 and Figures 1–20 , 22 )

Etymology. The species name consists in “ spinosus (Latin) ” (= spinule). The species is named after its spinal, pleural and marginal patches on dorsum of body with distinct and rather large spinules. Apterous viviparous female: Body elongate oval, yellow brown in life.

Mounted specimens: Body dark brown ( Fig.12 ) and oval, 1.81–2.02 mm long and 0.79–1.07 mm wide. For measurements see Table 1.

Part Apterous viviparous females (n=4) Apterous nymph (n=1)

Length (mm) Body length 1.97 (1.81–2.02) 1.61 Body width 0.93 (0.79–1.07) 0.91 Ant.I 0.11 (0.10–0.12) 0.10 Ant.II 0.055 (0.05–0.06) 0.06 Ant.III 0.62 (0.59–0.65) 0.34 Ant.IV 0.43 (0.40–0.45) 0.26 Ant.V 0.34 (0.32–0.35) 0.23 Ant.VIb 0.11 (0.10–0.12) 0.10 PT 0.71 (0.66–0.75) 0.57 URS 0.13 (0.12–0.14) 0.13 BW URS 0.07 (0.06–0.08) 0.07 Hind femur 0.77 (0.74–0.79) 0.52 Hind tibia 1.40 (1.35–1.45) 0.88 H.t.II 0.085(0.08–0.09) 0.084 Siphunculus 0.60 (0.59 – 0.61) 0.43 BW SIPH 0.15 (0.13 – 0.16) 0.14 DW SIPH 0.043 (0.040 – 0.045) 0.049 Cauda 0.19 (0.16–0.21) –

BW Cauda 0.12 (0.10–0.13) –

b.d.III 0.027 (0.027) 0.037 MW Hind tibia 0.035 (0.03–0.04) 0.044 Cephalic setae 0.035 (0.03–0.04) 0.025 Setae on Ant.III 0.011 (0.010–0.012) 0.005 Setae on Tergite I 0.030 (0.025–0.034) 0.029 Setae on Tergite VIII 0.045 (0.04–0.05) 0.04 Setae on Hind tibia 0.025 (0.022–0.027) 0.055 (longest setae)

Ratio (times) Whole antennae / Body 1.25 (1.12–1.37) 1.04 Hind femur /Antennal segment III 1.26 (1.19–1.33) 0.76 Hind tibia / Body 0.74 (0.68–0.80) 0.54 PT / Ant.VIb 6.26 (6.08–6.43) 5.57 URS / BW URS 1.94 (1.63–2.24) 1.80 URS / H.t.II 1.46 (1.41–1.51) 1.59 Cauda / BW Cauda 1.60 (1.27–1.93) –

Cephalic setae / b.d.III 1.28 (1.09–1.46) 0.67 Setae on Ant.III / b.d.III 0.41 (0.36–0.46) 0.13 Setae on Tergite VIII / b.d.III 1.83 (1.46–2.20) 1.07 Setae on hind tibia / MW Hind tibiae 0.82 (0.63–1.00) 1.22

Head and prothorax distinctly separate. Head dark brown. Dorsum of head with very sparse spinules near compound eyes and frontal tubercles, and the rest of area smooth, venter of head spinules ( Figs.1 , 13 ). Median frontal tubercle low but distinct; antennal tubercles developed, and the upper sides rounded, slightly diverging at inner sides; outline of front of head shallow W-shaped. Head with 1 pair of cephalic ventral setae, 1 pair of dorsal and 1 pair of ventral antennal tubercles setae with small and distinct tubercles at bases, and with incrassate apices; dorsal setae long with incrassate apices, with 2 pairs of dorsal setae between antennae, arranged longitudinally; and 2 pairs of dorsal setae between compound eyes, arranged transversely; cephalic setae about as long as dorsal setae, 0.03–0.04 mm long, 1.09–1.46 times and 1.27–1.36 times as long as basal diameter of antennal segment III, respectively. Ventral setae fine, long and acute. Eyes big with distinct ocular tubercles. Antennae 6-segmented, antennal segments I and II dark brown, distal parts of segments III–V and the basal part of segment VI pale brown, segments I and II with spinules, segment III smooth, segments IV–V weakly imbricated, segment VI imbricated ( Figs. 2, 3, 4 , 14 ). Antennae 1.12–1.37 times as long as body, length in proportion of segments I–VI: 15–20, 8–12, 100, 66–69, 53–57, 17–20+111–126, processus terminalis 6.08–6.43 times as long as basal part of the segment. Antennal setae short and blunt, segments I–VI each with 8, 4 or 5, 21, 8–11, 6–8, 2 or 3+3 setae, respectively, apex of processus terminalis with 3 setae, length of setae on segment III 0.005–0.010 mm, 0.36–0.46 times as long as basal diameter of the segment. Primary rhinaria ciliated, secondary rhinaria absent. Rostrum long, reaching beyond hind coxae; ultimate rostral segment wedge-shaped, apex dark brown (Figs.5,15), 1.63–2.24 times as long as its basal width, 1.41– 1.51 times as long as hind second tarsal segment, with 6 primary setae and 4–6 secondary setae.

Thorax distinctly segmented. Pronotum with wrinkles, meso- and metanotum with strong reticulations. Spinal, pleural and marginal setae on pro-, meso- and metathorax with brown sclerites at bases ornamented with large spinules, and these sclerites fused into a dark brown cross band, respectively. Venter with spinulous transverse rows. Pronotum with 1 pair of spinal, 1 pair of pleural and 1 pair of marginal setae; mesonotum with 2 pairs of spinal, 1 pair of pleural and 2 pairs of marginal setae, and metanotum with 1 pair of spinal, 1 pair of pleural and 2 pairs of marginal setae. Mesosternal furca with short stems ( Fig. 6 ). Legs long, pale brown, coxae with spinules, distal part of hind femora with sparse and hardly distinct spinules, others smooth. Hind femora 1.19–1.33 times as long as antennal segment III. Hind tibiae 0.68–0.80 times as long as body, setae on hind tibiae with acuminate to incrassate apices, 0.022–0.027 mm long, 0.63–1.00 times as long as middle diameter of the segment. First tarsal chaetotaxy: 4, 4, 3.

Abdomen indistinctly segmented. Abdominal tergites with reticulations, posterior area of siphunculi, tergites VII and VIII with spinules. Venter with spinulous transverse rows. Intersegmental sclerites brown. Spiracles nephroid, spiracular plates dark brown and slightly prominent. Setae on tergites I–VI on dark brown sclerites ornamented with rather dense and large spinules ( Figs.7 , 16 ), similar to setae on pro-, meso- and metanotum; and spinal and pleural sclerites fused into distinct transverse bands on tergite VII. Dorsal setae of body stout and long with distinct small tubercles at bases and with incrassate apices. Tergites I–VI each with 2 spinal setae, and 2, 2, 4, 6, 4, 2 marginal setae, respectively. Tergites VII with 8 setae and VIII with 4 long setae. Length of marginal setae on tergite I and spinal setae on tergite VIII are 0.91–1.27 times and 1.46–2.20 times as long as basal diameter of antennal segment III, respectively. Siphunculi wholly dark brown, cylindrical, widest at base, with sparse spinulose imbrications and with 5 or 6 rows of reticulations under slightly developed flange ( Figs. 8 , 17 ), 0.30–0.33 times as long as body, 3.75–4.65 times as long as its basal width, 2.85–3.76 times as long as cauda. Cauda brown, coniform, distal half slightly constricted ( Figs. 9 , 18 ), 1.27–1.93 times its basal width, with 4 setae. Anal plate brown, transverse oval, distal part of its slightly acuminate ( Fig. 10 ), with 6 setae. Genital plate brown ( Fig. 11 ), broad round with 10–12 short posterior setae and 4 long and 2 short anterior setae.

Fourth instar nymph of apterous viviparous female: Body oval, yellow in life.

Mounted specimens: Body light brown ( Fig.19 ). Body 1.61 mm long, 0.91 mm wide. General measurements see Table 1.

Head and prothorax distinctly separate, pale brown. Dorsum of head smooth except near antennal tubercles where sparsely spinulose, venter of head spinulose. Median frontal tubercle hardly prominent, antennal tubercles slightly developed, diverging at the upper of inner sides. Head with 1 pair of cephalic setae and 2 pairs of antennal tubercles setae on small raised sockets and slightly incrassate apices; dorsal setae similar to cephalic setae, with 2 pairs of dorsal setae between antennae, arranged longitudinally, and 2 pairs of dorsal setae between compound eyes, arranged transversely; length of cephalic setae 0.025 mm, dorsal setae 0.034 mm long, 0.67 times and 0.93 times as long as basal diameter of antennal segment III, respectively. Ventral setae fine, long with acute apices. Eyes big with distinct ocular tubercles. Antennae 6-segmented, pale brown, segments I and II with sparse spinules, segments III–V smooth, segment VI imbricated ( Fig. 20 ). Antennae 1.04 times as long as body, length in proportion of segments I–VI: 29, 18, 100, 78, 68, 31+173, processus terminalis 5.57 times as long as basal part of the segment. Antennal setae short and blunt, segments I–VI each with 8, 4 or 5, 19, 12, 14, 4+3 setae, respectively, apex of processus terminalis with 3 setae, length of setae on segment III 0.005 mm, 0.13 times as long as basal diameter of the segment. Primary rhinaria no ciliated, secondary rhinaria absent. Rostrum long, reaching beyond middle coxae; ultimate rostral segment wedge-shaped, rather stout and blunt, 1.80 times as long as its basal width, 1.59 times as long as hind second tarsal segment, with 6 primary setae and 4 secondary setae.

Thorax indistinctly segmented. Pro-, meso- and metanotum with wrinkles, venter with spinulous transverse rows. Setae on pro-, meso-and metanotum similar to dorsal setae of head, without brown sclerites at bases. Distribution and number of dorsal setae on thorax similar to apterous viviparous females. Legs stout, pale, coxae with very sparse spinules, 1/4 basal part of femora and 1/2 basal part of tibiae with rows of circle wrinkles, tarsi smooth. Hind femora 0.76 times as long as antennal segment III. Hind tibiae 0.54 times as long as body, setae on hind tibiae with acuminate apices, the longest setae 0.055 mm long, 1.22 times as long as middle diameter of the segment. First tarsal chaetotaxy: 4, 4, 3.

Abdomen indistinctly segmented. Abdominal tergites I–VI with reticulations, posterior area of siphunculi, tergites VII and VIII with spinules. Venter with spinulous transverse rows. Spiracles nephroid, spiracular plates pale and hardly prominent. Setae on abdominal tergites similar to dorsal setae on thorax, with pale sclerites at bases and without rather large spinules. Dorsal setae of body stout and long and with incrassate apices. Siphunculi wholly brown, cylindrical, widest at base, with sparsely spinulose imbrications and without reticulations under slightly developed flange, 0.27 times as long as body, 3.14 times as long as its basal width. Cauda coniform with 4 setae. Anal plate transverse oval, distal part of its slightly acuminate, with 4 setae.

Comments. The new species is closely related to M. woodwardiae (Takahashi) and M. manoji (Raha and Raychaudhuri) , but is distinguished from the two species shown as follows: (1) dorsal setae on thorax and abdominal tergites with sclerites at bases ornamented with rather dense and large spinules ( M. woodwardiae and M. manoji : setae with sclerites at bases having little or no distinct ornamentation), (2) setae on antennal segment III very much shorter, 0.36–0.46 times as long as basal diameter of antennal segment III ( M. woodwardiae : 1.00–1.25 times as long as basal diameter of antennal segment III), (3) antennae longer than body, 1.12–1.37 times as long as body ( M. manoji : antennae shorter than body, 0.67–0.70 times as long as body (Raha & Raychaudhuri, 1978)), (4) siphunculi wholly dark brown, with slightly developed flange ( M. manoji : siphunculi dark brown with the apex pale, without a distinct flange).

Material examined. Holotype: apterous viviparous female, CHINA: Hunan (Yizhang County, E112.9°, N24.9°, Alt. 1271m), 14 July 2008, No. 21808-1-1, host plant: Plagiogyria japonica , coll. X.M. Su; paratypes: 3 apterous viviparous females, Hunan (Yizhang County) 14 July 2008, No. 21804-1-1, same data as holotype; 1 apterous nymph, Hunan (Yizhang County), 14 July 2008, No. 21808-1-2, Plagiogyria japonica , coll. X.M. Su.

Distribution. China: Hunan (Yizhang County).

Biology. The species lives on Plagiogyria japonica ( Fig. 22 ). Colonies of this species seem to be very rare; at the first location less than ten individuals were present and only 2 apterous viviparous females and a few of nymphs were collected. Subsequently, 2 apterous viviparous females on the same host plant were collected at another site in Yizhang County, Hunan. Aphids of this species fed on the undersides of the new growth of ferns, without causing any deformations to the hosts. The species was not attended by ants.

Figures

FIGURE 22. Host plant of Macromyzus (Macromyzus) spinosus sp. nov. A., Plagiogyria japonica Thunb., B. young leaves infested by Macromyzus (Macromyzus) spinosus sp. nov.

FIGURES 1 – 11. Macromyzus (Macromyzus) spinosus sp. nov., apterous viviparous female: 1. dorsal (left) and ventral (right) view of head, 2. antennal segments I – III, 3. antennal segments IV – V, 4. antennal segment VI, 5. ultimate rostral segment, 6. mesosternal furca, 7. dorsal patches on abdominal tergites II – III, 8. siphunculus, 9. cauda, 10. anal plate, 11. gential plate. Scale bars = 0. 10 mm.

FIGURES 12 – 21. Macromyzus (Macromyzus) species. M. (M.) spinosus sp. nov. 12 – 20: apterous viviparous female: 12. dorsal view of body, 13. dorsal view of head, 14. antennal segments I – III, 15. ultimate rostral segment, 16. dorsal patches on abdominal tergites II – III, 17. siphunculus, 18. cauda. Fourth instar nymph: 19. dorsal view of body, 20. antennal segments I – III. M. (M.) woodwardiae Fourth instar nymph: 21. antennal segments I – III. Scale bar = 0.10 mm.