Stevekenia nothocestri, Percy, Diana M., 2017

Percy, Diana M., 2017, A new endemic psyllid genus, Stevekenia gen. nov. (Hemiptera: Psylloidea, Triozidae), from the Hawaiian Islands with two new and rare species on threatened host plants in the endemic genus Nothocestrum (Solanaceae), Zootaxa 4286 (3), pp. 370-380 : 373

Stevekenia nothocestri sp. nov.

( Figs. 1A–G ; 2A–H,N,P–Q; 3A–C,F,H–L,O–P)

Adult colour. General body colour mid-brown, yellow-green on abdomen; with darker brown markings on thorax, abdomen and legs. Fore wing membrane with a brown patch on the anal margin of cell cu2 and a fuscous cloud around clavus.

Adult structure as for generic description with the following species specific characters: Long setae densely distributed on ventral fore wing margin, two clusters of marginal radular spines present in cell m2, and radular spine clusters broader, cell m2 considerably larger than cell cu1 (ratio HM:HCU> 2), veins Cu1 and R subequal in length ( Fig. 1A,C–D ). Hind wing short, length> 2 mm, and> 0.5 fore wing length ( Fig. 1B ). Long setae on head, thorax, legs and sternites of female abdomen ( Figs. 1E,G and 3 L). Head with the two small anterior vertex extensions more convergent ( Fig. 2A ). Antennae with multiple rhinaria situated within small disks apically on antennal segment 4 (2–3 rhinaria), single or multiple on segment 6 (1–2 rhinaria) ( Fig. 2E–F ), and single rhinarium on each of segments 8, 9, the length of longest seta on the terminal segment subequal to length of segment 9. Hind tibia with large genual spine basally and markedly stalked apical spurs (1+2) with the pair of spurs conjoined at the base ( Fig. 2 N,P–Q). Male subgenital plate angled posteriorly in lateral view, paramere with a more extended anteriorly directed apex, distal aedeagus segment notably constricted medially with apical head large, bluntly acute, and> 0.5 length of distal segment ( Fig. 3A–C ,F). Female subgenital plate with medial bulge ventrally, and bluntly acute, almost truncate apically ( Fig. 3 H–I,L).

Egg. Long pedicel> 0.5 length of egg, and irregularly clustered cellular outgrowths, thickened tail also with cellular outgrowths ( Fig. 3 O–P).

Adult measurements (mm) and ratios. (1 male, 2 female) WL: 4.18–4.82; WW: 1.68–2.00; HW: 0.64–0.70; AL: 2.68–2.92; PB: 0.12; WL:WW: 2.41–2.52; WL:RsL: 2.89–3.07; CUR: 1.21–1.43; MR: 0.53–0.54; HM:HCU: 2.56–2.64; HW:VW: 1.77; VL:VW: 0.17–0.23; AL:HW: 4.20–4.39; HW:HT: 0.76–0.85; HT:HF: 1.35–1.42. Male terminalia: MP: 0.32; PL: 0.22; AEL: 0.20; PL:HW: 0.34; MP:PL: 1.48; PL:AEL: 1.08; AEL:AELH: 1.56; PL:SH: 0.90. Female terminalia: FP: 0.67–0.70; FSP: 0.41–0.42; RL: 0.21–0.22; OVH: 0.10–0.11; EL: 0.24–0.35; EW: 0.10–0.11; FP:RL: 3.11–3.23; FP:HW: 1.00; FP:SP: 1.62–1.71; EL:EW: 2.50–3.14.

Immature. Unknown.

Host plant. Nothocestrum longifolium .

Distribution. This species is endemic to Oahu and is only known from the Waianae Mountains, but the host plant is found on all the major Hawaiian Islands.

Etymology. Named for the association with the host, the endemic Hawaiian genus Nothocestrum (noun in the genitive case).

Comment. This species is most readily differentiated from S. aiea by the absence of the band of pigmentation across the basal 3rd of the wing, the larger size of cell m2 relative to cell cu1, the hind tibia with a large genual spine basally and pair of conjoined apical spurs, the shape of the paramere and aedeagus, and the shape of the female subgenital plate.

Type material. Holotype male (slide mounted), southern Waianae Mnts. , Oahu, USA, ex Nothocestrum longifolium , 22 May 2002, “364-02” D. Percy leg. ( BMNH) . Paratypes (slide mounted), 2f, as for holotype (BMNH).

Gene sequences. GenBank KY971541 ( COI), KY971543 (cytB).

Figures

FIGURE 1. A – G Stevekenia nothocestri, H – L Stevekenia aiea. A—fore wing; B—hind wing; C—detail of fore wing cell m 2 indicating position of two clusters of marginal radular spines, inset illustrates disbursed distribution of spines; D—detail of long setae on fore wing ventral margin and veins; E—dorsum of thorax; F—female habitus (cluster of eggs in abdomen); Ghead and thorax; H—fore wing (male); I—fore wing (female); J—hind wing (female); K—detail of fore wing cells m 1 and m 2 indicating position of single clusters of marginal radular spines towards posterior in each cell, inset illustrates narrow distribution of spines; L—detail of long setae on fore wing ventral margin and veins.

FIGURE 2. A – H, N, P – Q Stevekenia nothocestri, I – M, O, R Stevekenia aiea. A—head (dorsal view above, ventral view below) indicating position of posterior eye rim extensions (outlined), lateral ocelli, and anterior vertex extensions (in dorsal view) and position of medial ocellus below vertex extensions (in ventral view); B—head (dorso-anterior view) indicating short vertex with anterior vertex extensions; C—head (ventro-anterior view); D—head (lateral view) indicating position of posterior eye rim extension; E—single disk rhinarium on antennal segment 6 (illustration inset); F—multiple disk rhinaria on antennal segment 4; G—head and antenna; H—proboscis; I—head (dorsal view above, ventral view below) indicating position of posterior eye rim extensions, lateral ocelli, and anterior vertex extensions (in dorsal view) and position of medial ocellus below vertex extensions (in ventral view); J—detail of diverging anterior vertex extensions; K—head and antenna; L—proboscis; M, N—hind leg; O, P—genual spine at base of hind tibia; Q—apical tibial spurs and tarsi; R—detail of pair of apical tibial spurs not conjoined basally; S—detail of hind tarsal claws and arolium.

FIGURE 3. A – C, F, H – L, O – P Stevekenia nothocestri, D – E, G, M – N, Q Stevekenia aiea. A—male terminalia; B—sperm pump with comparative size of paramere; C—aedeagus; D—male terminalia; E—aedeagus; F, G—paramere (external surface); H—female terminalia; I—female subgenital plate (ventral view); J—female proctiger (dorsal view); K detail of dorsum of female proctiger indicating position of raised pores flanking anal ring; L female abdomen (with eggs) indicating long setae on sternites; M—female terminalia (with egg) indicating position of raised pore flanking anal ring, inset illustration of anal ring shape and circumanal pores; N—ovipositor; O – Q—eggs indicating pedicel, tail, plug-like structure, and surface cellular outgrowths (illustrated).