A new species of Aulacaspis Cockerell, 1893 from China with a key to Chinese species (Hemiptera, Coccoidea, Diaspididae)

Abstract A new species of armored scale insect, Aulacaspis zunyiensis sp. n. is described and illustrated from collections on cycads in China. A key to the Aulacaspis species known from China is provided.


Introduction
The scale insects or Coccoidea are small, sap-sucking insects with at least 30 families and approximately 8000 species (Andersen et al. 2010;Hodgson and Peronti 2012), sister to Aphidoidea in the suborder Sternorrhyncha. Together with Psylloidea and Aleyrodoidea, they comprise the hemipterous suborder Sternorrhyncha (Kondo et al. 2008).
Diaspididae is the largest family of scale insects with over 2650 described species in around 400 genera as currently known (García et al. 2016). Conventionally, new species of armored scales are diagnosed based on extreme modification of the adult females, with the complete loss of legs, reduction of the eyes and antennae, and modification in the terminal segments of abdomen (Andersen et al. 2010). Many armored scale insects are agricultural pests and invasive species (Miller et al. 2005). The higher classification within the family is inconsistent, but two of the major subfamilies are the Aspidiotinae and the Diaspidinae.
The genus Aulacaspis Cockerell, 1893 is a large group of Diaspididae that belongs to the subfamily Diaspidinae. The genus was originally established by Cockerell (1893) with Aspidiotus rosae Bouché, 1833 as the type species. Since the introduction of the generic name Aulacaspis, many additional species have been described (e.g., Chen 1983;Chou 1982;Tang 1986;Takagi 1961Takagi , 19671970;1988;1998;1999;2009;2010a;2010b;2012a;2012b;2014;2015;Williams 1988;2010;Rutherford 1915;Robinson 1917;Takahashi 1931). The genus currently comprises 120 species (García et al. 2016;Takagi. 2012b;2015), which occur in almost all zoogeographical regions except Antarctica (Suh 2013) and most are found in the Oriental and Palaearctic regions (Suh 2013). The species of this genus are associated with diverse plants and mostly feed on woody angiosperms (Takagi 2015). Some species of Aulacaspis, such as A. rosae (Bouché) and A. yasumatsui Takagi, are considered to be serious pests of ornamental plants (Milek et al. 2008;Miller et al. 2005;Watson and Marler 2014). China is the largest distributional region according to records of Aulacaspis, with 55 species having been reported in this country.
Recently, a new species of Aulacaspis was discovered in China, and it is described and illustrated herein, bringing the number of species recorded in this genus to 121, of which 56 are recorded from China. A key to the Chinese species of Aulacaspis is provided.

Materials and methods
Infested plant samples were collected in the field. Permanent slide mounts of adult females from the samples were made according to Henderson (2011). The illustrations of the adult female are drawn from slide-mounted specimens, with the figure displaying the dorsal body surface on the left side and the ventral body surface on the right side. Enlargements of significant features are located around the body. The morphological terminology and measurements in the descriptions follows those of Miller and Davidson (2005). The abbreviations in the text refer to different pygidial lobes: L1 stands for the median lobes, L2 for the second pair of lobes, L3 for the third pair of lobes, and L4 for the fourth pair of lobes. All measurements are given in micrometres (µm). Measurements were made using the measurement tools NIT-Elements D.
The type series of the new species is deposited in the Insect Collection of Shanxi Agricultural University, Taigu, Shanxi Province, China. Adult female. Slide-mounted adult female 1150-1301 µm long (holotype 1246 µm long); widest part of body 901-950 µm wide (holotype 922 µm wide). Body outline fusiform, derm membranous except for pygidium. Usually widest at mesothorax, lateral abdominal and thoracic lobes well-developed; prosomatic tubercles slightly produced. Cephalothorax. Antennae each with one seta. Anterior spiracles each with 14-16 trilocular pores in a cluster, posterior spiracles without trilocular pores. Pygidial lobes. With three pairs of lobes; L1 well-developed, zygotic basally, much larger than lateral lobes; protruding from pygidial margin, with one deep notch and small serrations on outer margin and one obvious notch on apex. Without setae between median lobes; L2 bilobate, inner lobule rounded, much larger than outer lobule, outer lobule very small, smaller than L3, a pair of obvious paraphyses arising from the mesal margin of the L2 lobes. L3 bilobate, slightly smaller than L2. Gland spines. One present between L1 and L2, one present between L2 and L3, two present on abdominal segment VI, 3-5 on abdominal segment III, 4-5 on abdominal segment IV, 5-6 on abdominal segment V, 1-2 on abdominal segment II, 0-1 on abdominal segment I. Gland spines on segment I and II shorter than those on other segments. Ventral gland tubercles present on submargins of metathorax and abdominal segments I and II. Ducts. Marginal macroducts, of two-barred type, 12.8-16.3 µm long (holotype 16.0 µm long), absent between L1, one present between L1 and L2, two present between L2 and L3, two present on the abdominal segment V. Dorsal macroducts on pygidium and abdominal segments shorter than marginal macroducts; 8.5-10.2 µm long (9.6 µm long), of two-barred type, arranged segmentally in submedian and submarginal rows; submarginal dorsal macroducts present on abdominal segment II to V: 10-11 on segment II, 8-9 on segment III, 5-6 on segment IV, 4-7 on segment V; submedian dorsal macroducts present on segment II to V: 4-6 on segment II, 5-6 on segment III, 4-5 on segment IV, 3-6 on segment V. Lateral macroducts few, 5-7 in total, present between abdominal II and III, of which, 2-3 on segment II, 3-4 on segment III, smaller than dorsal ducts present on abdominal and pygidium. Ventral microducts scattered on pygidium, few. Anal opening small, in holotype posterior margin of anal opening is situated 155 µm from base of L1. Perivulvar pores in five groups, 13-16 in the median group, 30-35 in each of the anteriolateral and 29-30 in each of the posteriolateral groups.
Remarks. This species is very similar to A. maesae (Takagi, 1970) in body shape. But differs in having (character-states on A. maesae in brackets): (i) posterior spiracle without trilocular pores (posterior spiracle with trilocular pores); (ii) dorsal macroducts absent from submedial region of abdominal segment VI (present); (iii) dorsal macroducts absent from submedial region of abdominal segment II (present).

Key to adult female Aulacaspis Cockerell from China
(The descriptions of three species, A. aceris Takahashi With