Malaxa acutipennis Melichar, 1914

Bartlett, Charles R. & Kennedy, Ashley C., 2018, A review of New World Malaxa (Hemiptera: Fulgoroidea: Delphacidae), Zootaxa 4441 (3), pp. 511-528 : 514-516

Malaxa acutipennis Melichar, 1914

( Figures 1–6 )

Type locality. Luzon , Laguna, Los Baños.

Amended Diagnosis. Color. Body color generally stramineous, thorax and abdomen darker in lateral compartments. Structure. Body length female 3.96 mm (3.81–4.10 mm, n=3; males dissected and not available for

measurement). Head including eyes narrower than pronotum (in dorsal view; Fig. 1 ), with vertex projecting slightly in front of eyes, narrowing distally, vertex length subequal to width at base. Submedian carinae distinct, uniting before fastigium, median carinae obscure. Frons long, parallel-sided, widest just before frontoclypeal suture (width of frons dorsally and at frontoclypeal suture equal; Fig. 4 ); l:w ratio 3.6–4.5:1. Rostrum just reaching mesothoracic trochanters. Antennae long and cylindrical except groove on front ventral portion of segment I; long, reaching or surpassing apex of clypeus ( Fig. 4 ), but not exceeding apex of mesothorax; antennal segment II about 2x length I (ratio I:II 0.43–0.46: 1). Pronotum length at midline nearly equal to length of vertex; all carinae (lateral and median) attaining hind margin. Mesonotum longer in middle line than vertex and pronotum together (1.41– 1.82: 1). Tegmina much longer than abdomen, clear with fuscous veins; apex of forewing distinctly pointed, leading margin arced so that wing width greatest near midlength ( Figs 2 , 35 ). Nodus just preceding midlength; Sc+RP separated from MP at basal cell, fork of SC+RA from RP near nodal line; Cu fork just past midlength of clavus; PCu+1A joined in basal third of clavus. Spinulation of hind leg 5-6-4 ( Fig. 3 ); calcar large and thick, concave on inner surface, without teeth along the hind margin, with an apical tooth. Pygofer roughly quadrate in lateral view, slightly longer ventrally than dorsally ( Fig. 5 ). Ventral margin of pygofer opening simple. Gonostyli forceps-like, with simple, acutely-pointed apex. Aedeagus strongly downcurved and divided into four spine-like projections. Anal segment of male short, ring-like, without process.

Remarks. Several differences can be observed between Malaxa acutipennis and the Chinese species in that genus. The most salient of these are that M. acutipennis has an apically pointed forewing (rounded in all other Malaxa ) with the leading margin arced (giving the wing a spatulate appearance; parallel-sided in all other Malaxa ); the more elongate pronotum with the carinae clearly reaching the hind margin (most other Malaxa with a relatively shorter pronotum with lateral carinae not reaching); and the genitalia with a simple ventral margin of the pygofer opening (vs. having projections on the opening of the pygofer); and the simple anal tube (most Chinese Malaxa bear a single, large, asymmetrical projection on the anal tube). Also, it appears that in Malaxa acutipennis , the frons is widest just above the frontoclypeal margin and the first antennal segment is longitudinally grooved on the ventral portion of the front. We did not examine other non-Chinese Malaxa outside of M. acutipennis (i.e., M. javanensis Muir , M. nigra Muir , and M. obtusipennis Muir ); however, Malaxa javanensis (see Muir 1919: 532, figure 3 [from Indonesia: Java]), has a large asymmetrical process on the anal tube and an acuminate midventral process on the opening of the pygofer. Malaxa nigra [ Philippine Islands; Luzon], was described by Muir as having a midventral process on the pygofer and a large spine on the left side of the anal tube. Malaxa obtusipennis [ Malaysia: Sabah] was described from 3 females, and so the features of the male terminalia are not available for consideration. Given our observations, it is reasonable to question the monophyly of Malaxa in the Old World, but at this time it is not clear whether the observed differences represent a sequence of autapomorphies for M. acutipennis , or alternatively that the genus-composition of Old World Malaxa requires reconsideration. However, our purpose was to contrast Malaxa from the Old World to those from the Neotropics. As presented below, we find that the Neotropical Malaxa differ from those in the Old World in a number of respects, and have here segregated them into two new genera.

Specimens examined ( Malaxa ). Malaxa acutipennis Melichar, 1914 : Philippines, Laguna, Mt. Makiling, Luzon, Baker [no date provided] (USNM; 3 females, 2 males).

Malaxa fusca Yang & Yang, 1986 : Taiwan, Nantou, Sin Shan forest road, 1 km W jct rt 66, 700 m, 23 54’39”N, 120 53’2”E, 11 June 2004, C. H. Dietrich, 07-1, vacuum ( INHS; 3 females).

Malaxa sp. : Thailand, Phetchabun P[rovince], Pha hong Cave , 17.vi.1997, C. W. & L. B. O’Brien (1 female, UDCC).

Figures

FIGURES 1–6. Malaxa acutipennis (Luzon, Philippines; female, except 5); 1, habitus dorsal view; 2, habitus lateral view; 3, hind tarsus, calcar and apex of tibia (ventral view); 4, face, frontal view; 5, male terminalia, left lateral view; 6, specimen label.

FIGURES 35–37. Forewing, line art, leading margin ventrad; 35, Malaxa acutipennis; 36, Lamaxa occidentalis; 37, Xalama microstyla.