Revision of Poliaspis (Hemiptera, Coccoidea, Diaspididae), with descriptions of 8 new species from Australia

Abstract Eight new Australian species of Poliaspis are described and illustrated: Poliaspis alluvia sp. n., Poliaspis araucariae sp. n., Poliaspis ceraflora sp. n., Poliaspis naamba sp. n., Poliaspis nalbo sp. n., Poliaspis narungga sp. n., Poliaspis ozothamnae sp. n., and Poliaspis waibenensis sp. n. Two described species are transferred into Poliaspis and are redescribed and illustrated: Lineaspis callitris (Laing) originally described by Laing as a species of Poliaspis, is transferred back into Poliaspis as Poliaspis callitris Laing, comb. rev., and Leonardaspis wilga (Leonardi) is transferred to Poliaspis as Poliaspis wilga (Leonardi), comb. n. Descriptions and illustrations are also provided for six of the fourteen previously-named Poliaspis species, including five from Australia: Poliaspis attenuata Brimblecombe, Poliaspis elongata Brimblecombe, Poliaspis exocarpi Maskell, Poliaspis nitens Fuller, and Poliaspis syringae Laing. Both Poliaspis cycadis Comstock and Poliaspis gaultheriae Green become junior synonyms of Poliaspis media Maskell. The species not treated here are Poliaspis intermedia Fuller (the location of the types is unknown and Fuller’s description is inadequate), Poliaspis casuarinicola Lindinger (missing types), Poliaspis incisa Takagi and de Faveri (recently, and well described in Takagi and de Faveri 2011), and the six New Zealand species recently revised by Henderson (2011). In addition, Laingaspis lanigera (Laing), the adult female of which has 8 clusters of perivulvar pores – as in Poliaspis species – is redescribed and illustrated. Lectotypes are designated for Laingaspis lanigera, Poliaspis callitris, Poliaspis exocarpi, Poliaspis media, and Poliaspis wilga. A key is provided to the species of Poliaspis, excluding Poliaspis casuarinicola and Poliaspis intermedia butincluding Poliaspis incisa and the New Zealand species: Poliaspis chathamica Henderson, Poliaspis floccosa Henderson, Poliaspis lactea (Maskell), Poliaspis media Maskell, Poliaspis raouliae Henderson and Poliaspis salicornicola Henderson.


introduction
Many armored scale insects (Diaspididae) are pests, and armored scales are disproportionately common in invasive faunas. About 2,500 species of armored scale insects have been described, and ten percent of these (250 spp.) are known to occur in Australia (http://scalenet.info/country_taxon/Australia/Diaspididae/). Maskell (1880) erected the genus Poliaspis by monotypy for P. media, a New Zealand species having eight groups of perivulvar pores occurring on the ventromedial surfaces of abdominal segments 6 and 5. Fourteen additional species sharing that distinction were described and added to Poliaspis by Maskell and other authors (Comstock 1883;Maskell 1892;Fuller 1897Fuller , 1899Lidgett 1898;Brimblecombe 1959;Henderson 2011). Seven described species of Poliaspis are from Australia. The Australian Plant Pest Database, integrating specimen data from several Australian insect collections, contains 398 sample records for Poliaspis species. Only 25% of these are identified to species. Amongst the unidentified material in the Australian National Insect Collection, and the Queensland Primary Industries Insect Collection, eight undescribed Poliaspis species were recognized.
Here, these eight new species of Poliaspis as well as six of the fourteen previouslynamed species are described and illustrated. We transfer two described species into Poliaspis and redescribe and illustrate these. We also redescribe and illustrate Laingaspis lanigera (Laing), the adult female of which has a similar distribution of perivulvar pores, but differs substantially in another key morphological feature. A key to the species of Poliaspis is provided, excluding P. casuarinicola and P. intermedia, but including Poliaspis incisa Takagi & De Faveri, recently described from Northern Queensland on mangroves (Takagi and De Faveri 2011).

Methods
Depositories are abbreviated as follows: ASCU, Agricultural Scientific Collections Unit, Orange Agricultural Institute, New South Wales; BMNH, the Natural History Museum, London, UK; NZAC, New Zealand Arthropod Collection, Auckland, NZ; QDPI, Queensland Primary Industries and Fisheries, Brisbane, Queensland, Australia; QMBA, Queensland Museum, Brisbane.
Measurements were made using the measurement tools in NIS-Elements BR 3.00, SPI (Build 455). For species with ≤ 10 specimens, measurements were taken from all specimens; for those with >10 specimens, 10 specimens were measured, chosen to represent the range of host plants and geographic localities present in the sample. The morphological terms for Diaspididae follow those of Miller and Davidson (2005). To make a clear distinction between the gland spines occurring on the pygidial margin, and the gland spines / tubercles occurring in submarginal areas anterior of the pygidium, all gland spines / tubercles anterior of the pygidium are referred to as gland tubercles. Because scale insects are bilaterally symmetrical, only one side of the body is described unless discussing features on the midline. For example, the number of anterolateral perivulvar pores given is that on one side of the body (not the sum of both sides), but the number of anteromedial pores is the total found in the cluster of pores extending across the midline (rather than dividing that number by 2). Species descriptions inherit and override attributes from the generic description, which can be thought of as an abstract base class as per the recommendations of Cook et al. (2010).
Following the convention for scale insects, each figure displays the dorsal body surface on the left side of the page, and the ventral body surface on the right. Enlargements of diagnostic features are located around the margin of each main figure. Geographic coordinates are provided for each collection location (with a few exceptions). If this information was not part of the original collection data (most cases), approximated coordinates are provided in square brackets. We estimated coordinates via the Google Geocoding API (http://code.google.com/apis/ maps/documentation/geocoding/), automating requests via a Python script (available from NBH by request). Description. Scale cover. Round to elongate-oval, white, flocculent wax sometimes present, exuvia terminal (after Henderson 2011).
Slide-mounted adult female. Body outline variable: linear, turbinate, pyriform, fusiform or oval, prepygidial abdominal margin weakly incised between segments to strongly lobed. Margin of pygidium rounded; incised between median lobes in some species, not incised in others. Two pairs of lobes in all species except Poliaspis wilga comb. n. (only medial pair) and some New Zealand species (3 rd lobe represented by three pointed projections); median lobes zygotic (except in P. ceraflora), parallel or divergent, apex variable -rounded or pointed; pair of setae between median lobes in most species; second lobes bi-lobed or undivided; basal scleroses present or absent. Simple gland spines present; most species with 1 gland spine on each side of each pygidial segment (other than segment 8), but gland spines may be absent on segment 7 (in area adjacent to lateral margin of medial lobe, e.g. P. ozothamnae sp. n.), or absent from pygidial segment 5 (P. ceraflora sp. n., P. callitris comb. rev.), or 2-6 may be present on each side of segments 5 and 6 (P. ozothamnae; P. nalbo sp. n.); length of gland spines variable, from about as long as median lobes to > 5 × length of median lobes. Anus in anterior third of pygidium; opening round. Trilocular pores in cluster near each anterior spiracle, some species also with pores near posterior spiracles. Antenna with 1 or 2 fleshy setae. Perivulvar pores quinquelocular, in 8 groups; 5 groups on abdominal segment 6, and 3 groups on abdominal segment 5. Dorsal ducts 2-barred; ducts on pygidial margin larger than medial ducts in most species; distribution of enlarged marginal ducts: 1 between median and second lobes; 1-2 on segment 6, laterad of second lobes; 2 on segment 5; dorsal ducts (other than those on margin) decreasing in size anteriorly; absent from abdominal segment 7; discrete submarginal and submedial rows of ducts present on any of abdominal segments 2-6: 1-10 submedial ducts present on abdominal segment 6, 4-12 submarginal and 4-15 submedial ducts present on segment 5. Some species with dorsal boss present on submargin of each of abdominal segments 1 and 3. Small ducts similar to dorsal ducts present on ventral submargin. Ventral gland tubercles in marginal / submarginal clusters on thoracic and pre-pygidial abdominal segments. Microducts present on venter, at least along abdominal submargin.
Comments. Nearly all other armored scale insect species have perivulvar pores in no more than 5 clusters, and restricted to abdominal segment 7. Species of Leucaspis Signoret and Lopholeucaspis Balachowsky are exceptions to this generalization; more than 5 clusters of multilocular pores may be present on the abdomen, but the extra pores occur on the submargin of abdominal segments 6 and 5. More pertinent exceptions are species in the African genera Rolaspis Hall, Tecaspis Hall, and Dentachionaspis MacGillivray, which have extra perivulvar pores, which occur in the same places as in Poliaspis (Hall 1946;Munting 1965Munting , 1967. Described African species with extra groups of perivulvar pores invariably have marginal macroducts with elongate ductules. This feature is enough of a reason for us to refrain from taking any nomenclatural action at this time. Description, n=1. Slide-mounted holotype female 952 μm long, body outline pyriform, thoracic and abdominal lobes weakly produced. Pygidium with 2 pairs of lobes; median lobes divergent, with dentate apex; margin between lobes incised to a variable degree; second lobe bi-lobed, each lobule with basal sclerosis, more strongly developed on medial lobule. Gland spines 24-38 μm long, 2-3 × length  of median lobes, 1 gland spine on margin of each pygidial segment; pair of setae between median lobes. Dorsal ducts smaller than marginal ducts present in rows; 8 submedial ducts present on segment 6; ca. 9 submarginal and ca. 10 submedial ducts on segment 5; ducts also present on segment 2. Perivulvar pores numerous: ca. 12 posteromedial, ca. 20 posterolateral, ca. 40 posterior, ca. 12 anteromedial, and ca. 5 anterolateral. Trilocular pores in cluster of 7-8 near anterior spiracle; 4 near posterior spiracle. Microducts few to numerous on dorsum of head, scattered anterior to anterior spiracles and mesad of gland tubercles on thorax and abdomen, few or absent on median abdomen. Antenna with 2 fleshy setae.

Key to species of
Comments. The relatively large number (ca 8) of submedial ducts on abdominal segment 6, as well as the large number of perivulvar pores (ca 90) can be used to distinguish P. alluvia from other species of Poliaspis.

Poliaspis araucariae
Comments. The one or two submedial ducts on abdominal segment 6, in addition to the absence of setae between the median lobes (also absent in P. callitris, and P. nitens) can be used to distinguish P. araucariae from other species of Poliaspis.
Comments. Adult females of P. attenuata are most similar to those of P. elongata Brimblecombe. Both have elongate, linear bodies. P. attenuata females can be distinguished on the basis of the longer-than wide, divergent median lobes (wider than long in P. elongata, with rounded apices).

Poliaspis ceraflora
Comments. This is the only species of Poliaspis with non-zygotic median lobes. The two pairs of minute gland spines are also distinctive, although P. callitris Laing shares the character of possessing only two pairs of small gland spines.
Etymology. The species name is derived from the Latin words for wax (cera) and flower (floris), in reference to the common name, wax flower, of the host plant genus Chamelaucium.
Comments. P. exocarpi is far and away the most polyphagous and wide spread species of Poliaspis in Australia. There is also a considerable amount of morphological variation present among samples (e.g. the number of submedial ducts on dorsum of abdominal segment 6). The relatively small size of the median lobes (smaller than or equal in size to second lobes) and the relatively long size of the gland spines (up to 43 μm, about 5 × length of medial lobes) are also diagnostic.
Comments. The type material of P. cycadis is morphologically inseparable from P. media. Both species were discovered at about the same time (1880s) and at first the host differences (cycads versus wide host range) and geographic disjunction of North America and New Zealand presented a conundrum. Examination of the type material of P. gaultheriae, previously synonymized with P. cycadis by Balachowsky (1954), revealed it to be conspecific, but the only recorded host of P. gaultheriae was Gaultheria depressa, an endemic New Zealand plant that had been transported from NZ to Scotland. Thus the logical connection to P. media as the senior synonym became more credible. A further point is that specimens identified as P. cycadis collected on Cycas revoluta from Kew Gardens, UK, 1887, Coll. J.W. Douglas, are misidentifications of a mixture of Poliaspis syringae Laing and Furchadaspis zamiae (Morgan). We suggest that various collections of Poliaspis species on cycads may be chance populations on these host plants.
Comments. P. naamba is very similar to P. waibenensis sp. n. P. naamba adult females can be distinguished from those of P. waibenensis by (1) lacking a strong duct spur between the medial and second lobes (present in P. waibenensis); (2) having pores associated with the posterior spiracles (lacking in P. waibenensis); and (3) with prepygidial margin of abdomen only weakly lobed (strongly lobed in P. waibenensis). The two species also have different host associations, with P. naamba almost always collected from Melaleuca species, and P. waibenensis from mangrove plants.
Etymology. The species name is taken from the Aborignal word naamba used in reference to red bottlebrush Melaleuca viminalis. This species has been most often found associated with Melaleuca species.
Comments. In contrast to many other Australian species of Poliaspis, which are very similar to one another, P. nalbo is very distinctive. It can be easily recognized by (1) the large, rounded, parallel median lobes; (2) the extra gland spines on the margin of abdominal segments 5 and 6; (3) the cluster of gland tubercles present on the ventral surface of the head (also present in P. narungga); (4) the absence of microducts from the dorsal surface of the head.
Etymology. The species name is taken from the name of one of the aboriginal groups that originally populated the type locality Maleny, the Nalbo people.
Comments. P. narungga is the only species of Poliaspis in which the adult females lack gland spines, but gland tubercles are numerous in submarginal areas of the abdomen and thorax, including a cluster anterior to the anterior spiracle. Also distinctive are (1) the lack of differentiation between marginal and dorsal ducts, and (2) the dorsal macroducts on the pygidium not being arranged into distinct submedial and submarginal clusters.
Etymology. The Narungga people were the inhabitants of the Yorke Peninsula prior to the arrival of Europeans.   2.7.1914, No. 178 G. Brittin Collection (NZAC).
Comments. Fuller (1897) described the median lobes of P. nitens as being very short and wide. That is unique among Poliaspis species and matches the material we have examined from ASCU, which was also collected from the same host and area. No setae were observed between the median lobes, but there appear to be a pair of empty setal sockets present and it is possible that the setae have broken off.
The adult female of P. nitens can be distinguished from other species of Poliaspis on the basis of the very short and broad median lobes. Three other species treated here have median lobes smaller than the second lobes: P. callitris, P. exocarpi and P. araucariae. In P. exocarpi and P. araucariae the body margin between median lobes is slightly incised, and in P. araucariae the median lobes are strongly divergent. In P. callitris the body margin is not clearly incised between the median lobes, but each medial lobe is longer than wide and has a pointed apex.  Description, n=10. Slide-mounted adult female 809-1256 μm long, body outline turbinate. Pygidium with 2 pairs of lobes; median lobes zygotic, parallel, closeset, lobes connected via narrow sclerosis, each lobe wider than long, apex obtuserounded and dentate; margin between lobes not incised; second lobe not bi-lobed, roughly pointed, apex notched in some specimens, close to medial lobe. Gland spines 8-17 μm long, about as long as median lobes, gland spine absent from margin of pygidial segment 7 (between medial and second lobes), 4-7 spines on margin of each of abdominal segments 5-6; pair of setae between median lobes. Marginal ducts: 1 on abdominal segment 7, 1 on segment 6, not differentiated from dorsal ducts on segment 5. Dorsal ducts present in clusters (i.e. several ducts across); ca. 5 submedial ducts present on segment 6; ca. 12 marginal-submarginal and ca. 12 submedial ducts on segment 5. Perivulvar pores: 3-6 posteromedial, 7-15 posterolateral, 10-18 posterior, 4-5 anteromedial, and 3-6 anterolateral. Trilocular pores in cluster of 7-16 near anterior spiracle; 2-8 near posterior spiracle. Microducts absent on dorsal surface of head, scattered on ventral surface of thorax and abdomen. Antenna with 1 fleshy seta. Gland tubercles absent from ventral surface of head anterior to anterior spiracle.
Comments. P. ozothamnae is distinguishable from other species of Poliaspis by having (1) the second lobe close set to medial lobe, without a gland spine near lateral edge of medial lobe; (2) only 2 differentiated marginal ducts; (3) the 2-8 pores near each posterior spiracle; and (4) having multiple gland spines on each pygidial segment other than 8.

Poliaspis syringae
Comments. P. syringae is most similar to P. naamba and P. waibenensis. Adult females of P. syringae can be distinguished from those by (1) median lobes much larger than second lobes (similar in size in P. naamba and P. waibenensis); and (2) second lobes without basal sclerosis (present in P. naamba and P. waibenensis). The specimens examined here are from Eremocitrus (or native citrus) and Capparis. The specimens from Capparis are larger than those from Eremocitrus (smallest from Capparis 1233 μm, largest from Eremocitrus 1056 μm), have more pores around the anterior spiracle (ca 18 vs ca. 6), and have slightly longer gland spines on the longer side of the range observed among samples from Eremocritus.
Comments. This species has the diagnostic distribution of perivulvar pores found among species of Poliaspis but differs in an important feature: namely, 1-barred ducts arranged in a dense marginal swath on the pygidial dorsum. 1-barred ducts and gland tubercles, which are also present in this species, is an unusual combination among armored scale insect species. Laingaspis laniger (Laing)