Hybothoracaphis laevigata, Chen, Jing, Jiang, Liyun & Qiao, Gexia, 2016

Chen, Jing, Jiang, Liyun & Qiao, Gexia, 2016, Hybothoracaphis, a new genus of Nipponaphidini (Hemiptera, Aphididae, Hormaphidinae) from China and its phylogenetic placement based on multiple genes, Zootaxa 4170 (2), pp. 375-383 : 376-380

Hybothoracaphis laevigata sp. nov.

( Figs1–25 , Table 1 )

Etymology. The new species is named for the almost smooth dorsum of prosoma. “ laevigata ” (Latin) means “smooth”.

Description. Apterous viviparous females: Body oval, aleyrodiform, strongly sclerotized, thickened, with a conspicuous median dorsal ridge ( Fig. 24 ). Dark brown in life ( Figs 22–24 ). For morphometric data see Table 1 .

Mounted specimens. Body brown; legs light brown; muscle attachment plates dark brown; rostrum, cauda, anal plate, and genital plate pale in color. Prosoma consisting of fused head, thorax, and abdominal segment I; abdominal segments II–VII fused and completely separated from prosoma; abdominal segment VIII free ( Figs 1 , 11 ). Dorsum of prosoma smooth, with a few wrinkles. Muscle attachment plates distinct, forming radial pattern with dorsal wrinkles ( Figs 1 , 11, 12 ). Central axis of dorsal prosoma with clusters of irregular-shaped pustules, located before and behind the muscle attachment plates ( Figs 1 , 12 ); the largest one located on the anterior area of head, distinctly elevated, spherical ( Figs 2 , 13 ); others protuberant, flat, or indistinct. Posterior marginal area of dorsal prosoma with indistinct oval or spindle-shaped markings in some specimens. The margin of dorsal prosoma with a wide transversely striped band ( Figs 1, 3 , 11, 14 ). Abdominal tergites II–VII with short and long ripples, tergite VIII with scaly imbrications medially and transverse stripes posterior marginally ( Fig. 1 ). Marginal vertical area of body covered with mosaic-like ornamentation, protuberant ( Figs 1, 4 , 11, 15 ). Two pairs of thoracic spiracles conspicuous ( Fig. 15 , indicated with arrows in Fig. 1 ). Dorsal setae of body very short, fine, and pointed. Head with a pair of cephalic setae; dorsum of prosoma with 11 pairs of submarginal setae, among head with 4 pairs anterior to eyes, pro-, meso-, and metanotum each with 2 pairs, abdominal tergite I with a pair; the spinal area of prosoma with 0–2 setae; abdominal tergites II–VII each with a pair of submarginal setae; tergite VIII with 4 setae ( Fig. 1 ). Frons not protuberant. Eyes 3-faceted ( Fig. 1 ). Antennae very small, unsegmented, with L-shaped bend and 2 apical setae ( Figs 5 , 16 ). Primary rhinaria small, rounded, and placed closely. Rostrum short, reaching to fore coxae. Ultimate rostral segment wedge-shaped, with 2 pairs of primary setae and a pair of secondary setae ( Figs 6 , 17 ). Legs short, exposed outside body, smooth, trochanter and femur fused ( Fig. 11 ). Setae on legs sparse, hind tibiae with stiff and blunt setae on distal part. First tarsal chaetotaxy: 2 or 3, 3, 2. Dorsoapical setae on second tarsal segment expanded at apex and longer than claws. Claws normal. Siphunculi pore-like, slightly raised, on abdominal tergite IV ( Figs 7 , 18 ). Cauda and anal plate with spinules, genital plate with spinulose transverse stripes ( Figs 8–10 ). Cauda knobbed, constricted at base, with 7–9 setae ( Figs 8 , 19 ). Anal plate bilobed, each lobe with 6 setae ( Figs 9 , 20 ). Genital plate broadly rounded, with 2 anterior setae and 9–12 setae along the posterior margin ( Figs 10 , 21 ).

Specimens examined. Holotype: apterous viviparous female, CHINA: Tibet (Mainling County, 29.44°N, 94.72°E, altitude 2940 m), 1.viii.2014, No. 32788-1-2-1, on Quercus aquifolioides , coll. J. Chen and X. C. Zhu ( NZMC) . Paratypes: 3 apterous viviparous females (COI: KU530576 ; CytB: KU530577 ; EF-1α: KU530578 ), with the same collection data as holotype (NZMC); 2 apterous viviparous females, CHINA: Tibet ( Nyingchi City , 29.88°N, 93.43°E, altitude 3330 m), 2.viii.2010, No. 25731-1-1, on Quercus aquifolioides , coll. G. X. Qiao, Q. H. Liu, Y. Wang, and R. Chen ( NHM) ; 2 apterous viviparous females (COI: KU530570 ), No. 25731 (NZMC); 2 apterous viviparous females ( COI: KU530571 ), CHINA: Tibet (Bome County, 29.61°N, 96.39°E, altitude 3350 m), 5.viii.2014, No. 29575, on Quercus aquifolioides , coll. J. Chen and X. C. Zhu ( NZMC) ; 1 apterous viviparous female ( COI: KU530572 ), CHINA: Tibet (Zayu County, 28.80°N, 97.50°E, altitude 2660 m), 7.viii.2014, No.

29650, on Quercus aquifolioides , coll. J. Chen and X. C. Zhu (NZMC); 1 apterous viviparous female ( COI: KU530573 ), CHINA: Tibet (Bayi Town, Mt. Biri , 29.64°N, 94.38°E, altitude 3250 m), 31.vii.2014, No. 32765, on Quercus aquifolioides , coll. J. Chen, R. Chen, and X. C. Zhu ( NZMC) ; 1 apterous viviparous female ( COI: KU530574 ), CHINA: Tibet (Bayi Town, Mt. Biri , 29.65°N, 94.38°E, altitude 3200 m), 31.vii.2014, No. 32776, on Quercus aquifolioides , coll. J. Chen, R. Chen, and X. C. Zhu ( NZMC) ; 3 apterous viviparous females ( COI: KU530575 ), CHINA: Tibet (Mainling County, 29.31°N, 94.34°E, altitude 2950 m), 1.viii.2014, No. 32781, on Quercus aquifolioides , coll. J. Chen and X. C. Zhu ( NZMC) .

Distribution. China (Tibet).

Host plant. Quercus aquifolioides .

Biology. Aphids live along the veins on the undersides of leaves of Quercus aquifolioides ( Figs 22–25 ). The life cycle is unknown.

Comments. The new species most resembles Thoracaphis kumaoni Chakrabarti & Debnath, 2011 , but differs from it as follows: antennae unsegmented (the latter: 3-segmented); a conspicuous median dorsal ridge present on body (the latter: absent); clusters of irregular-shaped pustules present along central axis of dorsal prosoma (the latter: absent); dorsum of prosoma almost smooth (the latter: variably corrugated); the marginal band on dorsal prosoma transversely striped (the latter: polygonal reticulated) ( Chakrabarti & Debnath, 2011).

Figures

FIGURES 1 – 10. Hybothoracaphis laevigata sp. nov. Apterous viviparous female: 1. dorsal view of body (arrows indicate thoracic spiracles on one side of body); 2. pustule cluster on anterior area of head; 3. transversely striped band on margin of prosoma; 4. mosaic-like ornamentation on marginal vertical area of body; 5. antenna; 6. ultimate rostral segment; 7. siphunculus; 8. cauda; 9. anal plate; 10. genital plate. Scale bars = 0.10 mm.

FIGURES 11 – 21. Hybothoracaphis laevigata sp. nov. Apterous viviparous female: 11. dorsal view of body; 12. pustule clusters along central axis of dorsal prosoma and muscle attachment plates; 13. pustule cluster on anterior area of head; 14. transversely striped band on margin of prosoma; 15. thoracic spiracle surrounded by mosaic-like ornamentation; 16. antenna; 17. ultimate rostral segment; 18. siphunculus; 19. cauda; 20. anal plate; 21. genital plate. Scale bars = 0.10 mm.

FIGURES 22 – 25. Hybothoracaphis laevigata sp. nov. Aphid colonies on the undersides of leaves of Quercus aquifolioides: 22, 23. aphids sitting along the leaf veins; 24. apterous adults; 25. nymphs bearing a little white wax.

Tables

TABLE 1. Morphometric data of Hybothoracaphis laevigata sp. nov.

Parts (For abbreviations see Materials and methods)	Apterous viviparae (n=15) Mean Range	Standard Deviation
Length Body length (mm) Body width	1.093 0.854–1.283 0.850 0.620–0.956	0.106 0.093
Whole antenna	0.027 0.022–0.031	0.004
URS	0.079 0.072–0.091	0.007
Hind trochanter and femur	0.101 0.086–0.120	0.011
Hind tibia	0.100 0.086–0.122	0.010
2HT	0.035 0.027–0.042	0.004
AD SIPH	0.022 0.019–0.025	0.002
Cauda	0.032 0.022–0.037	0.005
BW Cauda	0.038 0.029–0.043	0.004
MW Hind tibia	0.019 0.017–0.020	0.001
Cephalic setae	0.007 0.006–0.007	0.001
Submarginal setae on Tergite I	0.012 0.010–0.017	0.002
Spinal setae on Tergite VIII	0.016 0.012–0.019	0.002
Setae on Hind tibia	0.010 0.007–0.012	0.002
No. of Antenna setae on URS	2 6
Tergite VIII	4
Cauda	7–9
Each lobe of AP	6
GP	11–14
Ratio Whole antenna / Body (times) Hind tibia / Body	0.02 0.02–0.03 0.09 0.08–0.11	0.005 0.009
URS / BW URS	2.03 1.82–2.47	0.199
URS / 2HT	2.18 1.82–2.64	0.242
Cauda / BW Cauda	0.83 0.73–0.94	0.076
Setae on Hind tibia / MW Hind tibia	0.52 0.38–0.71	0.087