Monomalpha Emeljanov, 2000

Löcker, Birgit, 2020, Revision of the Australian planthopper genus Monomalpha Emeljanov with the description of the new genus Latissima (Hemiptera: Auchenorrhyncha Fulgoromorpha: Cixiidae: Cixiini), Zootaxa 4858 (3), pp. 375-393 : 377-379

Genus Monomalpha Emeljanov, 2000

Monomalpha Emeljanov, 2000: 14 .

Type species: Monomalpha gratiosa Emeljanov, 2000 , by original designation.

Morphology. Body length: ♂ 4.3–4.8 mm; ♀ 4.2–5.5 mm.

Head: Vertex about as long as wide or slightly wider than long with the exception of M. stenocara (1.4 x longer than wide); vertex divided into apical and subapical compartment by subapical carina; apical carina deeply u-shaped. Apical transverse carina merged with raised (in relief) area ventrally of apical transverse carina on top of head. Frons invisible in dorsal view. Frons about as long as wide or longer than wide. Maximum width of frons no more than twice apical width (only in M. stenocara about twice apical width); position of maximum width distinctly dorsad of centre of frontoclypeal suture. Median carina of frons complete. Lateral carinae of frons slightly elevated, foliaceous, slightly to moderately extending laterally, concealing base of antennae. Median ocellus of frons absent. Rostrum surpassing hind coxae and reaching or just not reaching hind femura. Subapical segment of rostrum less than twice as long as apical segment.

Thorax: Pronotum with median carina moderately to well developed; pronotum about the same length in middle as laterally; submedian carinae running parallel to eyes. Mesonotum with well-developed lateral carinae; median carina well developed near anterior margin, evanescent near posterior margin. Forewings moderately tectiform; surpassing tip of abdomen; widest around apex of clavus; concavity at costal border absent; no tubercles in cells at apex of wing, only along veins; tubercles in pterostigma scattered; ScP+R+M forming a very long common stem distad of basal cell; fork of ScP+RA and RP distinctly basad (far away) of fork CuA1 and CuA2; fork of CuA1 and CuA 2 in apical half of forewing; icu, where it inserts at CuP, distinctly distad of apex of clavus; RA apically unforked; MP3+4 unforked; nodus of y-vein more or less central within clavus. Hind leg: tibia with 6 apical spines (grouped in two groups with a small to large gap in between, or grouped without distinct gap), outermost spine the largest followed by two shorter spines that appear retracted (forming a second row), innermost three spines on same row as outermost spine, with middle spine of the three slightly shorter than the others; 1 st tarsomere with 7 apical teeth and no platellae; 2 nd tarsomere 6–7 apical teeth and no platellae but with up to 3 very fine setae (= subapical setae).

Male genitalia: Phallotheca very wide at base, narrow in middle section; with 2–4 spines of varying length, some of which can be bifurcate; bifurcate ventral process absent ( M. fletcheri and M. stenocara ) or rudimentary ( M. gratiosa ).

Female genitalia: Segment IX truncate, with rounded edges, with a concave disc bearing a slightly to moderately elevated dividing wall running from ovipositor to anal tube, waxplate absent. Ovipositor very long, sabreshaped, slightly curved upwards, protruding much further than anal style ( Fig. 1 ). Anal tube in M. gratiosa very short, widening towards apex, in M. fletcheri slightly longer, slightly widening or same width throughout. Anal style long (as long or longer than dorsal length of anal tube), slightly to much longer (up to twice as long) than remainder of 11 th segment.

Diagnosis: Monomalpha is endemic to Australia and can be distinguished from all other Australian Cixiidae by the following combination of characters: apex of head with two transverse carinae; apical transverse carina of vertex deeply u-shaped ( Figs 3E , 4D , 7D ); apical transverse carina merged with raised (in relief) area ventrally of apical transverse carina ( Figs 4C , 5D ); forewings with tubercles only along veins (not within cells in apical third of wing); median carina of frons unforked ( Fig. 4C ); frons without median ocellus; second hind tarsomere without platellae, but with three or fewer very fine setae ( Figs 3F , 6E ); fork of CuA1 and CuA 2 in apical half of forewing ( Figs 3A , 5A, 5B ).

Remarks. The original description of the genus ( Emeljanov 2000) mentions the following characters: second hind tarsomere with the four inner teeth bearing thin subapical setae; forewing with M [MP according to Bourgoin et al. 2015 terminology] five-pointed, with 3 MA branches [MP1+2 according to Bourgoin et al. 2015 terminology] or only two-pointed (in the type species); short stalk ScRM [stalk ScP+R+M according to Bourgoin et al. 2015 terminology] present. Examination of the holotype, paratypes (those that were available for examination) and other material examined, revealed only up to 3 subapical setae (= very fine setae) on the second tarsomere and only up to 3 MP branches (MP1+2 bifurcate or unforked, MP3+4 unforked) and compared to most Cixiidae ScP+R+M forms a rather long stem in Monomalpha .

Distribution. Australia (Qld, NSW including Lord Howe Island).

Figures

FIGURE 1: Female genitalia: A Monomalpha gratiosa; B–F Monomalpha fletcheri.

FIGURE 3. Monomalpha fletcheri: A–B habitus (A holotype); C–E head and thorax; F hind tarsi; G hind tibia.

FIGURE 4. Monomalpha gratiosa: A habitus; B–D head and thorax.

FIGURE 5. Monomalpha gratiosa (holotype). A habitus dorsal; B habitus lateral; C–E head and thorax; F hind tibiae and tarsi. Photos courtesy of Dr Olívia Evangelista (ANIC). Used with permission.

FIGURE 6. Monomalpha stenocara (holotype): A habitus; B–D head and thorax; E hind tarsi.

FIGURE 7. Latissima isleyensis (holotype): A habitus; B–D head and thorax; E hind tibia and tarsi.