Nigritergaphis crassisetosa, Zhang, Bin, Lou, Ya-Meng & Qiao, Ge-Xia, 2013

Zhang, Bin, Lou, Ya-Meng & Qiao, Ge-Xia, 2013, A new genus and species of Macrosiphini (Hemiptera, Aphididae) from China, living on Isodon eriocalyx, ZooKeys 359, pp. 1-12 : 3-8

Nigritergaphis crassisetosa sp. n. Figures 1-38

Locus typicus.

China (Yunnan: Kunming City, Heilongtan Town, Alt. 1922m, 102.44°E, 25.8°N).

Etymology.

The specific name, crassisetosa is composed of the Latin words “crassis” (= thick) and “setosa” (= covered with hairs), due to the long and thick setae of body.

Description.

Apterous viviparous female: Body elliptical, 1.42-1.58 mm long, 0.77-0.96 mm wide. Adult body black in life, nymphs dark green (Fig. 38).

Mounted specimens.

Body. Dorsum brown. Antennal segments I-II dark brown, segment V and base of segment VI brown, others pale. Siphunculi dark brown. For morphometric data see Table 1.

Head. Smooth dorsally, except top surface of median frontal tubercle which is rough. Median frontal tubercle poorly developed, lower than antennal tubercles which are more developed and have divergent inner faces, so that frons is shallowly “W” -shaped (Figs 1, 18, 19); dorsum of head pigmented (Fig. 18), ventral surface with sparse spinules. Dorsal cephalic setae thick and stiff, arising from tuberculate bases. Head with 3 pairs of frontal setae, 1 pair of dorsal setae between antennae, and 3 pairs of dorsal setae between eyes (Figs 1, 19), frontal setae 2.0-2.8 times as long as basal diameter of antennal segment III. Eyes with about 25 facets. Antennae 5- or 6-segmented (Figs 2, 3, 20), about 0.4 of body length; segments I–II segments slightly rough, segments III–V with weak imbrications, segment VI with distinctly transverse imbrications. Processus terminalis 2.2-2.9 × base of segment VI (6-segmented antennae). Antennal setae short and pointed, segments I–VI (I-V) respectively with 4-5, 3-4, 5-7, 3-4, 3-4, 2-3+2 (3-4, 3-4, 1-3, 3-4, 1-3+3-4) setae; apex of processus terminalis with 3 or 4 setae. Setae on segment III 0.5-0.9 times as long as basal diameter of the segment. Primary rhinaria ciliated, secondary rhinaria absent (Figs 3, 20). Rostrum (Fig. 18) reaching mid-coxae; ultimate rostral segment wedge-shaped, 1.6-2.0 times as long as its basal width, 1.3-1.6 times as long as second hind tarsal segment, with 2-3 accessory setae.

Thorax. Dorsum of thorax imperfectly pigmented (Fig. 18). Pronotum with 3 pairs of spinal, 1 pair of pleural and 2 pairs of marginal setae. Mesosternal furca (Figs 5, 22) with a short stem or separate arms. Base of femora with 2-3 small round pseudo-sensoria. Hind femur 1.9-2.3 times longer than antennal segment III (when antennae 6-segmented). Hind tibia 0.28-0.34 times as long as body. Setae on legs long and pointed, setae on hind tibiae 0.7-0.9 times as long as middle diameter of the segment. First tarsal chaetotaxy: 2, 2, 2.

Abdomen. Abdominal tergites smooth, and sclerotic (Fig. 18). Dorsal setae of body numerous, long, thick and stiff, arising from tuberculate base. Marginal setae slightly longer than spinal and pleural setae. Ventral setae very sparse, fine and pointed, distinctly shorter than dorsal setae. Abdominal tergite I with 24-38 dorsal setae, tergite VIII with 4 setae, occasionally 3. Length of marginal setae on tergite I 3.0-4.1 times as long as basal diameter of antennal segment III; dorsal setae on tergite VIII 3.0-4.5 times as long as basal diameter of antennal segment III. Spiracles small, oval or reniform, opened; spiracular plates oval. Siphunculi (Figs 6, 7, 23, 24) short and tapering, with distinct imbrication and a well-developed flange, 1.5-2.5 times as long as their basal width, 1.1-1.5 times as long as cauda; siphunculi of 7 specimens with 1 long seta (Figs 7, 24). Cauda (Figs 8, 25) nearly helmet-shaped, with short rows of spinules; 0.8-1.2 times as long as basal width, with 4 long curved setae. Anal plate semi-circular, with short rows of large spinules; with 10-13 setae. Genital plate (Figs 11, 28) transversely oval, with transverse rows of spinules; 2 anterior setae, 10-12 posterior setae along margin uniformly distributed.

Alate viviparous female: Body elliptical, 1.50-1.64 mm long, 0.69-0.79 mm wide. For morphometric data see Table 1.

Mounted specimens.

Head. Median frontal tubercle weakly developed, slightly lower than antennal tubercles which are more developed with divergent inner faces, frons “W” -shaped (Figs 12, 30); dorsum of head pigmented (Figs 29, 30); ventral surface of head with sparse spinules. Head with 3 pairs of frontal setae, 2 pairs of dorsal setae between antennae, and 2 pairs of setae between eyes (Figs 12, 30). Frontal setae 0.9-1.0 times as long as basal diameter of antennal segment III. Antennae 6-segmented (Figs 13, 14, 31) 0.5-0.7 times as long as body; ventral side of segment I with weak spinulose imbrications, ventral sides of segment II-VI with imbrications. Antennal setae pointed, segments I–VI each with 4-5, 4-5, 6-11, 3-5, 3-5, 2+0, respectively, apex of processus terminalis with 3-4 setae. Setae on segment III 0.5-0.7 times as long as basal diameter of the segment. Primary rhinaria ciliated. Secondary rhinaria large and round, segment III with 18-34, segment VI with 7-12, and segment V with 1-3 (Figs 13, 14, 31). Ultimate rostral segment 1.8-2.2 times as long as its basal width, 1.3-1.4 times as long as second hind tarsal segment, with 2-4 pairs of accessory setae.

Thorax. Dorsum of thorax completely sclerotized (Fig. 29). Pronotum with 2-3 spinal setae, 1 pair of pleural and 1 pair of marginal setae. Base of femora with 3-5 small and round pseudo-sensoria, basal 1/3 rather thin; hind femur 1.4-1.7 times as long as antennal segment III. Hind tibia 0.4-0.5 times as long as body. Setae on hind tibiae 0.9-1.0 times as long as middle diameter of the segment.

Abdomen. Abdominal tergites each with one pair of marginal patches and an imperfect dark spino-pleural band; those on tergites I-III and VIII narrow; marginal patches with spinulose short stripes (Fig. 29). Dorsal setae numerous, thick, stiff and pointed, arising from tuberculate base; ventral setae very sparse, fine and pointed, ap prox. as long as dorsal setae. Abdominal tergite I with 12-16 spino-pleural and 4-6 marginal setae, tergite II with 14-20 spino-pleural and 10-14 marginal setae, tergite III with 14-22 spino-pleural and 11-14 marginal setae, tergite IV with 14-21 spino-pleural and 11-14 marginal setae, tergite V with 14-17 spino-pleural and 8-10 marginal setae, tergite VI with 8-13 spino-pleural and 8-10 marginal setae, tergite VII with 7-10 dorsal setae, tergite VIII with 3-5 setae. Marginal setae on tergite I 0.9-1.3 times as long as basal diameter of antennal segment III; dorsal setae on tergite VIII 1.3-1.9 times as long as basal diameter of antennal segment III. Siphunculi similar in shape to those of apterous viviparous females; 5 of 12 specimens each with 1 long seta on siphunculi (Figs 15, 32); 2.3-2.6 times as long as their basal width, 1.0-1.2 times as long as cauda.

Type series.

Holotype: apterous viviparous female, China: Yunnan Province, Kunming City (Heilongtan Town), 11 Dec. 2012, No. Y9259-1-2-2, on Isodon eriocalyx , coll. J.X. Pu. Paratypes: 12 apterous viviparous females and 11 alate viviparous females, with the same collection data as holotype; 12 apterous viviparous females and1 alate viviparous female, 27 Oct. 2011, No. Y9162, on Isodon eriocalyx , coll. J.X. Pu. The holotype and paratypes of the new species are deposited in the National Zoological Museum of China, Institute of Zoology, Chinese Academy of Sciences, Beijing.

Biology.

The species colonizes the underside of the leaves of the host plant, Isodon eriocalyx , inducing the leaves to become curled, swollen or blistered to form “pseudogalls”, and causing stunting of growth (Figs 36, 37, 38).

Apterae with 5-segmented antennae and 6-segmented antennae occur at different times of year, the former in October, the latter in December. Seemingly, there is a seasonal effect on morphology in this species. No sexual morphs were observed.

Taxonomic notes.

Blackman and Eastop (2006, 2013) provided a key to all apterous viviparous females on the plant genus Isodon . The new species can be inserted as an additional couplet (couplet 3a) in their key:

Couplets 4 to 20 without modification.