Pariaconus dorsostriatus Percy

Percy, Diana M., 2017, Making the most of your host: the Metrosideros-feeding psyllids (Hemiptera, Psylloidea) of the Hawaiian Islands, ZooKeys 649, pp. 1-163 : 41

Pariaconus dorsostriatus Percy sp. n. Figures 17, 47 A–J

Adult colour.

Variable, usually bicoloured with orange-brown, cream or yellow to greenish-yellow thorax and abdomen, and a dark dorsal stripe from the head extending part or all the length of the body. Fore wing fuscous, especially around anal margin.

Adult structure.

Fore wing apex bluntly acute to rounded; dispersed spinules present in all cells, but reduced or absent in cell r1; setae on margins and veins short to minute (Fig. 17 A–B). Antennae short (av. length 0.63; ratio AL:HW av. 1.23); genal processes short (ratio VL:GP av. 3.87); short setae on vertex, minute on thorax; distal proboscis segment short (av. length 0.07); hind tibia longer than head width (ratio HW:HT av. 0.91) (Fig. 17 C–I). Male terminalia (Fig. 17 J–N, Q–R): paramere length subequal to proctiger (ratio MP:PL av. 1.01), broad at base, not sinusoidal, tapering evenly to small apical hook appearing flat topped from lateral aspect; distal aedeagus segment shorter than paramere (ratio PL:AEL av. 1.23), base rounded and slightly inflated, apex triangular not developed into a hook (ratio AEL:AELH av. 2.19). Female terminalia (Fig. 17 O–P, V–W): proctiger short, subequal to subgenital plate, usually depressed medially (ratio FP:FSP av. 0.93), anal ring short (ratio FP:RL av. 2.65), apex bluntly acute; subgenital plate with slight medial bulge ventrally, apex bluntly acute; ovipositor apex with no or very reduced serrations above, two reduced serrations below, valvulae dorsalis not strongly convex dorsally.

Egg.

Unpigmented, narrowly oval, marginally sinusoidal, entire surface with interrupted striations, medium-short pedicel positioned 1/4 length from base, tail short (Fig. 17 S–U).

Immature.

Colour and structure: Pale cream, yellow to green. 5th instar: Broadly ovoid and ventro-dorsally flattened wing buds only slightly protruding and distinct humeral lobes (Fig. 47 A–B, J). Tarsi with small reduced claws. Circumanal ring wide (CPW:RW av. 4.24), and more or less straight, with a single row of uninterrupted elongate cells (Fig. 47A). Chaetotaxy: 5th instar: Continuous marginal ring of blunt, weakly bisected sectasetae (Fig. 47C). Dorsal surface rugose and either without setae or with scattered minute simple setae. 1st instar (Fig. 47I): Margin with broadly fan-shaped sectasetae (9 pairs anterior margin of head, 1 pair postocular, 1 pair on each wing bud, 12 pairs abdominal); by the 2nd instar there is a continuous marginal ring of sectasetae (Fig. 47H).

Host plant notes.

Apparently prefers glabrous morphotypes, with pit galls mostly on the lower leaf surface, occasionally on the upper leaf surface.

Island.

Hawaii.

Distribution notes.

Appears to be widespread; collected from four regions that group into distinct clusters in the DNA analysis: (a) Puu Makaala, (b) Alili plus Kau, (c) Humuula (Hamakua Coast), and (d) the Kohala region (Fig. 3).

Biology.

Immatures make pit galls, typically on the lower leaf surface that are initially shallow, becoming deeper with older instars (Fig. 47 D–G).

Etymology.

Named for the dark dorsal stripe that is frequently present in this species and signifies its affiliation with the bicoloratus group (adjective in the nominative singular).

Comments.

One of the largest species in the bicoloratus group. Two forms are recognized (Fig. 17): form kohalensis (based on the type is found in the Kohala region, with broader, shorter paramere, and shorter genae) (Fig. 17 J–N), and form communis (more common and widespread, has a more slender, longer paramere, e.g. Fig. 17 Q–R [with more round apex in Kau/Alili] and more well developed genae).

Type material.

Holotype male (slide mounted, BMNH). See Table 2 for details of type and other material examined for this study.