Lasiacantha Stål, 1873 (Drake & Ruhoff, 1961)

Cassis, Gerasimos & Symonds, Celia, 2011, Systematics, biogeography and host plant associations of the lace bug genus Lasiacantha Stål in Australia (Insecta: Hemiptera: Heteroptera: Tingidae) 2818, Zootaxa 2818 (1), pp. 1-63 : 14-15

Genus Lasiacantha Stål, 1873

Tingis (Lasiacantha) Stål 1873: 130 (gen. nov.)

Lasiacantha: Stål 1874: 56 (raised to genus level); Lethierry and Severin 1896: 18 (catalogue); Horvath 1906: 14, 59 (key); Drake 1953: 92; Drake and Ruhoff 1960: 63; Drake and Ruhoff 1965: 253 (catalogue); Péricart 1982: 358 (description); Péricart 1983: 268 (description; Mediterranean); Cassis and Gross 1995: 419 (Australian catalogue)

Monanthia (Lasiacantha) : Puton 1886: 33 (new subgenus arrangement)

Jannaeus Distant 1909: 118 (gen. nov.; type species Jannaeus cuneatus ); Drake and Ruhoff 1960: 69 (new synonymy); Drake and Ruhoff 1965: 253 (synonymy)

Myrmecotingis Hacker 1928: 182 (gen. nov.; type species Myrmecotingis leai Hacker 1928 , by monotypy); Drake and Ruhoff 1960: 69 (synonymy)

Type species. Tingis (Lasiacantha) hedenborgii Stål, 1873 , by subsequent designation by Oshanin 1912: 44.

Remarks. The genus Lasiacantha was first described as a subgenus of Tingis Fabricius 1803 by Stål (1873) for the Mediterranean species, Lasiacantha hedenborgii ( Stål 1873) , and has an extensive nomenclatorial history. Lasiacantha was also placed as a subgenus in Monanthia Le Peletier and Serville by Puton (1886). However, it has usually been treated at generic rank. Drake and Ruhoff (1965) catalogued the world fauna recognising 21 species, from the Eastern Hemisphere. Subsequent to this catalogue, a further 18 species have been described, three from southern India ( Livingstone & Bai 2005); one species from Laos ( Guilbert 2007); one species from Java ( Stusak 1978); two species from central Asia ( Hoberlandt 1977, Nonnaizab 1985), subsequently synonymised by Golub (1988) into one species ( Golub 1988); one species from Europe ( Stusak 1971); and 11 new African species (Göllner- Scheiding 2005, Duarte-Rodrigues 1990, 1987a, 1987b, 1981a, 1981b). Two previously described African species were synonymised with others ( Göllner-Scheiding 2005), resulting in 19 species currently recognised from Africa ( Göllner-Scheiding 2005). The majority of species are found in the Afrotropical region (including South Africa and Madagascar) and the western Palearctic (see also Péricart 1983), with only three species known from the Oriental regions of the Palearctic, five from the Indomalayan region and none documented from Oceania.

With a wide range of morphological variation across the species described worldwide, the monophyly of this genus requires examination.

To date, three species from Australia have been known ( Cassis & Gross 1995).

Hacker (1928) erected a new genus, Myrmecotingis , for an enigmatic, short winged species from Western Australia ( M. leai Hacker 1928 ), which Hacker (1929) subsequently transferred to Lasiacantha , resulting in a new generic synonymy. Drake (1955) described new Australian species belonging to Lasiacantha ( L. discordis Drake 1955 ) and Furcilliger ( F. compta Drake 1942 , was subsequently transferred to Lasiacantha (Drake & Ruhoff 1961)) , and herein is removed from Lasiacantha (see below)). Additionally, Drake (1947) described Tingis aemula , which herein is transferred into Lasiacantha (see below).

Lasiacantha compta ( Drake, 1942) , is designated herein as incertae sedis, because it lacks the revised diagnostic characters for Lasiacantha . In particular, characters that place this species outside Lasiacantha are: paranota infolded and adpressed; lateral pronotal carinae medially convergent and truncate; collum with thick collar covering posterior margin of head to eyes and extending to the bucculae, collum weakly elevated posterior to the collum (as opposed to the strongly elevated collum from the anterior pronotal margin in Lasiacantha ); and, sutural area of macropters with very small, numerous areolae, up to 10 areolae wide as opposed to Lasiacantha with large areolae in sutural area, maximally 6 areolae wide). We have refrained from treating this species any further in this work, pending a more thorough examination of genus-group boundaries in Australian lace bugs, but here remove it from Lasiacantha .

In our previous work on the genus Inoma Hacker, 1927 ( Cassis & Symonds 2008), we discussed in detail, the characters of generic importance in discriminating Inoma from Lasiacantha ; in so doing, we recognised a putatively close relationship between these taxa. Our studies in this work have resulted in minor modifications of our genus-group discriminating characters, resulting in the following character definition for Lasiacantha based on Australian taxa only: 1) dorsum with extensive distribution of either elongate woolly setae and/or elongate hairlike setae, often with hooked apex, most dense on pronotum and discoidal area; 2) lateral margins of pronotum and hemelytra, and cubital and R+M veins of hemelytra, always with setiferous tubercles; 3) head with five (mostly) elongate spines, with medial spine either undivided or bifurcate; 4) pronotal collum enlarged, either subtriangular of columnar, mostly vertically oriented, sometimes anteriorly projected; 5) pronotal paranota enlarged, free and not recurved, projected laterally to dorsolaterally, biseriate to quadriseriate, expanded medially, with lateral margins strongly rounded, semicircular; 6) pronotum tricarinate, all carinae continuous, medial and lateral carinae strongly elevated; 7) medial pronotal carinae usually more elevated and often biseriate medially, and always higher than lateral carinae; 8) lateral carinae subparallel, usually uniseriate, rarely biseriate, sometimes a little sinuate posteriorly, not strongly convergent towards midline, never subcontiguous with medial carinae; 9) macropters with costal area moderately expanded, areolae greater in area than areolae of discoidal area, but subequal to areolae in sutural area; 10) costal area biseriate or triseriate in macropters, and uniseriate in brachypters; 11) metathoracic glands closed, external efferent system not apparent, and, 12) male endosoma lacking any basal endosomal sclerites.

Our examination in this work has broadened our understanding of generic limits and morphology space for a group of genera in the Tinginae , which includes a component of the putatively paraphyletic genus Tingis , Inoma , Lasiacantha , and another Australian endemic genus Caloloma Drake and Bruner. Our observations of the diagnostic character systems in these genera are summarised in Table 5, and we conclude they are diagnosable, although our examination of extralimital taxa is limited. Our observations here result in modification of our previous diagnoses of Lasiacantha and Inoma ( Cassis & Symonds 2008) , such that the following characters are not discontinuous, and also occur in some species of Lasiacantha : 1) strongly keeled pronotal collum, but when present is more elevated in Lasiacantha ; and 2) setiferous tubercles present on the keel and anterior margin of collum, only sometimes present, but always present in Inoma .

Particular diagnostic characters distinguishing the Australian species of Lasiacantha from Inoma are: 1) expanded, rounded, semicircular paranota, at least two areolae wide in macropters and brachypters; 2) highly elevated, enlarged collum; 3) medial carina always higher than lateral carinae, and 4) dorsal vestiture more greatly elongate, both woolly and hairlike setal types.

Additionally, interesting morphological differences of fifth instar larvae of Australian Lasiacantha have been found compared to Inoma and are as follows: 1) elongate to greatly elongate cephalic spines, a forked medial spine, and an elongate dorsal branch on occipital spines; 2) simple marginal processes, rather than the somewhat branched and/or setiferous processes in Inoma ; 3) dorsal surface with sparse distribution of simple cuticular outgrowths, rather than dense distribution of (predominantly) stellate cuticular outgrowths found in Inoma ; 4) rounded, expanded pronotal margins, whereas in Inoma the lateral margins of the pronotum are linear and unexpanded; and 5) the partially formed conelike collum, whereas in Inoma larvae the collum area is flat and unformed.

Our phylogenetic analysis above, recognised three clades within the Australian Lasiacantha ( Fig. 1 ). These three species groups can be recognised by the following diagnoses:

Clade 1 (node 4) (spp. incl. L. discordis , L. serraseta and L. vittata ): macropterous; AI and AII minor setiferous tubercles in singular rows; major setiferous tubercles short, terminal seta shorter than half length of tuberculate base; dark brown costal band; pronotum and hemelytra with moderately elongate, slightly thickened and wavy hairlike setae; vestiture sparse on hemelytra; head with flattened, scalelike setae; abdominal venter with adpressed, flattened, short, scalelike setae; medial cephalic spine straight; column subtriangular and vertically projected; keel of collum and pronotal carinae with major setiferous tubercles.

Clade 2 (node 7) (spp. incl. L. gingera , L. graminicola , L. kosciuszko , L. leai and L. windorah ): brachypterous; AI sometimes elongate; minor setiferous tubercles on AI and AII in multiple rows; major setiferous tubercles short to moderate length, terminal seta equal length to mostly longer than tuberculate base, sometimes greatly elongate; dorsum with dense distribution of moderately elongate hairlike setae only (rarely woolly setae, only in L. windorah ); head with woolly setae; abdominal venter with porrect, straight, moderately elongate hairlike setae; medial cephalic spine straight; collum columnar and anteriorly projected; and, surface of collum and pronotal carinae with major setiferous tubercles.

Clade 3 (node 10) (spp. incl. L. aureolus , L. darwini , L. dysmikos , L. ephemera , L. eremophila , L. inaquosa , L. luritja , L. nipha , L. pilbara and L. quilpie ): macropterous; AI and AII minor setiferous tubercles in singular rows; major setiferous tubercles short to moderate length, terminal seta shorter than tuberculate base, sometimes less than half length of base; pronotum with two setal types (mostly), being woolly setae on disc and hairlike setae on carinae, collum and paranota (rarely also woolly); head with woolly setae; abdominal venter with adpressed, flattened, short, scalelike setae; medial cephalic spine forked; column columnar and vertically projected; and, keel of collum and pronotal carinae rarely with major setiferous tubercles.

Figures

FIGURE 1. Implied weights phylogeny for Australian Lasiacantha Stål, 1873, with nodes numbered (refer to Table 3 for character state changes at nodes), bootstrap values are given as branch supports, and biogeographic area and host plant mapped next to the species name. Map of areas of endemism, redrawn from Crisp et al. (1995). Abbreviations for biogeographic areas as follows: ED = Eastern Desert; EQ = Eastern Queensland; MM = Macleay-McPherson; P = Pilbara; SE = Southeast New South Wales; SW = Southwest Western Australia; TAS = Tasmania; and, WD = Western Desert.