Eriococcus korthalsellae Henderson

Henderson, Rosa C., Sultan, Amir & Robertson, Alastair W., 2010, Scale insect fauna (Hemiptera: Sternorrhyncha: Coccoidea) of New Zealand’s pygmy mistletoes (Korthalsella: Viscaceae) with description of three new species: Leucaspis albotecta, L. trilobata (Diaspididae) and Eriococcus korthalsellae (Eriococcidae), Zootaxa 2644, pp. 1-24 : 15-20

Eriococcus korthalsellae Henderson sp. nov.

Figs 8–11

Unmounted material: The felt cover of the adult female appeared resinous and brown. Nymphs had a marginal fringe of quite broad wax filaments.

Adult female ( Fig. 8 ), measurements taken from 7 specimens.

Body shape elongate-oval, 0.69–1.07 mm long, 0.35–0.75 mm wide; derm membranous except for anal lobes. Eyespots present. Marginal setae robust, conical with rounded tips, 10–15 μm long, with 2 setae on each side of each abdominal segment and then forming a line on thorax to head. Antennae 6-segmented, 112– 120 μm long, 3rd segment longest; fleshy setae: 1 each on segments IV and V, 3 on VI. Labium 50–55 μm long with 5 pairs of setae. Anal lobes large, broadly triangular, 110–120 μm long and 67–75 μm wide, with dorsal base margin distinctly curved; with a prominence on inner apex and apical seta offset on outer angle; strongly sclerotised with robust papillae over all dorsal surface and on outer submargin of ventral surface, remaining ventral surface smooth; anal lobe setae lengths: anterior inner margin seta 15–20 μm, posterior inner margin seta 20–23 μm, lateral margin seta 12–17 μm; ventral surface seta 20–23 μm, apical seta 70–75 μm; suranal seta 30–42 μm long; outer dorsal seta and inner margin setae curved and blunt tipped; ventral seta and suranal seta straight and sharply pointed. Anal ring cellular, ventral, with 4 pairs of anal ring setae. Legs well developed; metathoracic leg with translucent pores about size of 5-locular pores, distributed over one half of dorsal surface of coxa and with a few on distal femur; metathoracic coxa not much larger than coxae of other legs, metathoracic leg lengths: coxa 30–37 μm, trochanter + femur 77–87 μm, tibia + tarsus 90–107 μm, claw 17– 20 μm, denticle present.

Dorsum. Dorsal setae of 2 sizes: (i) larger robust setae slightly smaller than and similar to marginal setae, distributed in a median band 1–4 setae wide from mesothorax to mid-abdomen; (ii) minute truncate setae about 4 μm long distributed as submedian pairs on last abdominal segments, in a submarginal line on abdomen, and with a few additional setae on thorax. With 2 kinds of tubular ducts: (i) largest a macrotubular duct 20–23 μm long, with fairly symmetrical cup and moderately thick ductule leading to a large gland, distributed in a broad submarginal band, scattered medially and submedially on thorax, head and abdomen; (ii) microduct, half length of macrotubular duct at 10–12 μm long, comprised of a slender outer ductule and a dark vestibule at its base with a proximal filament leading to a minute gland; a microduct associated with and opening near the base of each large robust seta, and scattered over dorsum; also with several microducts on dorsal surface of each anal lobe.

Venter. Submedian abdominal setae flagellate, of various sizes; with a line of small pointed straight setae on submargin, each seta about 10 μm long; with 3 pairs of interantennal setae. Macrotubular ducts and microducts absent. Disc pores 5-locular, small, 3–4 μm in diameter, distributed in a line between each anal lobe and posterior spiracle, with 3 to 4 pores near each spiracle, and a few scattered over head and near mouthparts. Mesothoracic spiracles 25-32 μm long including the muscle plate (apodeme), 10 μm wide across peritreme; metathoracic spiracles 25– 30 μm long, 7–10 μm wide across peritreme. Vulva present on abdominal segment VI–VII.

Comments. This new species is closest to Eriococcus myrsinae Hoy but can be separated by the following diagnostic features: (i) the shape of the anal lobes, which are broadly triangular with a distinctly curved dorsal basal margin and with a ratio width to length about 1:1.2 (more elongate-tapering and dorsal margin nearly straight transversely in E. myrsinae with width to length ratio about 1: 1.5); (ii) anal lobes more papillate and rugose than on E. myrsinae ; (iii) possession of a denticle on the claw (absent in E. myrsinae ); and (iv) a microduct associated with each robust seta (not so associated in E. myrsinae ). Other diagnostic features are the presence of translucent pores on the metacoxae and metafemora; the robust dorsal surface setae forming a longitudinal median band; and minute truncate dorsal setae. The adult female of Eriococcus parsonsiae Henderson (Henderson 2006) was described as having papillate and rugose anal lobes, but in that species the lobes are elongate; in addition, the robust marginal setae on E. parsonsiae are pointed rather than conical, ventral disc pores are numerous and widespread especially over abdomen, translucent pores are absent from metathoracic femora, and the medium-sized duct described below for the 2nd-instar male nymph of E. korthalsellae is present on both dorsum and venter of the adult female E. parsonsiae (absent on adult female E. korthalsellae ).

2nd-instar female ( Fig. 9), measurements taken from 3 specimens.

Body shape elongate-oval, length 0.57–0.58 mm, width 0.34–0.36 mm. Derm membranous apart from sclerotised anal lobes. Eyespots present on margin of head. Marginal setae very slightly larger than dorsal setae, 10–17 μm long. Labium 42 μm long, with 5 pairs of setae. Antennae 90–105 μm long, with 6 segments, segment III longest; setal distribution as for adult female. Anal lobes 55–62 μm long and 37–42 μm wide; lightly sclerotised, not rugose or papillate except for isolated patch at base of each lobe; with 3 or 4 [2 in Fig.] microducts on dorsal surface of each lobe; anal lobe setae lengths: anterior inner margin seta 10–12 μm, posterior inner margin seta 12–15 μm, lateral margin seta 10–12 μm; ventral surface seta 17 μm, apical seta on outer angle, 55–65 μm; suranal seta 17–22 μm long; outer dorsal seta and inner margin setae slightly curved and blunt tipped; ventral seta and suranal seta sharply pointed. Anal ring cellular, ventral, with 3 pairs of setae. Legs well developed; all coxae similar in size; metathoracic leg lengths: coxa 22–25 μm, trochanter + femur 70 μm, tibia + tarsus 87–29 μm, claw 15 μm, denticle present.

Dorsum. Dorsal robust setae distributed as 5 pairs in a longitudinal median band from prothorax to abdomen II, then diminishing in size to 4 pairs of minute truncate setae to segment VI. Microducts as for adult female. Macrotubular ducts absent.

Venter. Ventral abdominal setae flagellate submedially and in a line of 8 small pointed setae each side on submargin to mesothorax. Disc pores 5-locular, distributed in a line between metathoracic spiracle and near to anal lobe on each side, with 1 pore by each spiracle and several scattered on thorax. Mesothoracic and metathoracic spiracles each about 12 μm long and 7.5 μm wide across peritreme. Macrotubular ducts and microducts absent.

Comments. Generally smaller than adult female; lacking vulva, macrotubular ducts, and translucent pores on metathoracic legs; anal lobes sclerotised but not strongly papillate.

2nd-instar male ( Fig. 10 ), measurements taken from 3 specimens.

Body shape elongate-oval, length 0.58–0.67 mm, width 0.32–0.41 mm. Derm membranous apart from anal lobes. Eye spots present on margin of head. Marginal setae very slightly larger than dorsal setae, 10–17 μm long. Labium 37–45 μm long, with 5 pairs of setae. Antennae 102–120 μm long, with 6 segments, segment III longest with pseudosegment apparent at about mid point; setal distribution as for adult female. Anal lobes 55–62 μm long and 37–42 μm wide; lightly sclerotised, not rugose or papillate except for isolated patch at base of each lobe; with 2 or 3 microducts on dorsal surface of each lobe; anal lobe setae lengths: anterior and posterior inner margin setae each 15–17 μm, lateral margin seta 12–15 μm; ventral surface seta 17–20 μm, apical seta on outer angle, 60–62 μm; suranal seta 22–35 μm long; outer dorsal seta and inner margin setae slightly curved and blunt tipped; ventral seta and suranal seta sharply pointed. Anal ring cellular, ventral, with 3 pairs of setae. Legs well developed; all coxae similar in size; metathoracic leg lengths: coxa 35–40 μm, trochanter + femur 92–95 μm, tibia + tarsus 115–120 μm, claw 17–20 μm, denticle present.

Dorsum. Dorsal robust setae distributed as 0–7 pairs in a longitudinal median band from prothorax to abdoman II, then minute truncate setae continue the line to segment VI, and also form a submarginal line each side of body. Microducts as for adult female. With 2 kinds of macrotubular ducts: (i) similar to macrotubular ducts of adult female except shorter, 12–15 μm long, moderately numerous throughout dorsum; (ii) smaller sized duct 7–10 μm long, similar in length to microduct but nearly as wide as large macrotubular duct, with cup roundly-oval in dorsal view with a pointed lip on one side leading to a short filament without a visible gland; these ducts few, distributed submarginally with 1 on each side of each abdominal segment and similarly on thorax and head.

Venter. Ventral abdominal setae flagellate submedially and in a line of 8 medium size (longer than on 2nd-instar female), pointed setae each side on submargin to mesothorax. Disc pores 5-locular, distributed in a line from each metathoracic spiracle to near each anal lobe, and 1–3 pores by each spiracle plus several scattered on thorax. Mesothoracic and metathoracic spiracles each about 12 μm long and 7.5 μm wide across peritreme. Macrotubular ducts and microducts absent.

Comments. Similar to 2nd-instar female nymph except for presence of 2 kinds of dorsal tubular ducts, and with antennae and various body setae slightly longer, and ventral disc pores more numerous. Note phenotypic variation in number of dorsal robust setae in median band: the highest value was from the type series collection, Turangi, North Island, while the lowest value was from the Banks Peninsula, South Island collection.

1st-instar nymph ( Fig. 11), measurements taken from 5 specimens.

Body shape elongate-oval, length 0.38–0.47 mm, width 0.21–0.29 mm. Derm membranous. Eyespots present on margin of head. Marginal setae 12–17 μm long, more elongate and pointed than marginal setae on other instars, with 1 seta on each

side of each abdominal segment, and becoming a line anteriorly, with several additional setae submarginally on head. Antennae 77-95 μm long with 6 segments, segment III just a little longer than other segments, with 1 fleshy seta on each of segments IV–VI.

Labium: 32–37 μm long, with 5 pairs of setae. Anal lobes small, 22–25 μm long, 22–30 μm wide, with rounded apex, very lightly sclerotised; anal lobe setae lengths: anterior inner margin seta 10–12 μm, posterior inner margin seta 15–17 μm, lateral margin seta 10–12 μm; ventral surface seta 25–30 μm, apical seta, 70–87 μm; suranal seta 17–20 μm long; outer dorsal seta and inner margin setae not slightly curved or blunt tipped; ventral seta and suranal seta flagellate. Anal ring cellular, ventral at base of lobes, with 6 setae.

Legs well developed; all coxae similar in size; metathoracic leg lengths: coxa 20–22 μm, trochanter + femur 57–62 μm, tibia + tarsus 72–77 μm, claw 15 μm, denticle present. Dorsum. Dorsal setae all minute truncate setae about 4 μm long, distributed as submedian pairs and in a submarginal line each side of body. Microducts present near each marginal seta on abdomen, less numerous anteriorly, with a few scattered on thorax. Macrotubular ducts absent.

Venter. Ventral abdominal setae flagellate, and with a few small pointed setae on submargin. Disc pores 5-locular, distributed in a line from each metathoracic spiracle to near each anal lobe, with 1 pore by each spiracle. Mesothoracic and metathoracic spiracles each about 15–17 μm long and 5 μm wide across peritreme. Macrotubular ducts and microducts absent.

Comments. As for 2nd-instar female, except shape of robust marginal setae more pointed than conical, robust setae absent from dorsum, microducts and quinquelocular pores much less frequent.

Material examined: HOLOTYPE: Female, here designated. NEW ZEALAND, TO, Turangi, Motuoapa, 19 March 2009, A. Sultan, Korthalsella salicornioides parasitic on Leptospermum scoparium , #09-073b [1]: 1 F. Barcode NZAC 02008385.

Paratypes: as for holotype: #073a, c-i [8]: 9 F, 3 f2nd, 2 m 2nd, 5 1st.

Other material examined. BP, Rotorua, Whakarewarewa Geothermal Reserve, 10 Apr 2010, A. Sultan, Korthalsella salicornioides , #10-056 [1]: 1 m 2nd; WA, Gladstone, Longbush Road, Mangahuia Stream Bush, 26 Feb 2010, A. Sultan, Korthalsella lindsayi , #10-047a–b [2]: 3 F (1 mature + 3 young), 1 f2nd, 2 m 2nd; MC, Banks Peninsula, Otanerito Bay, 4 Jan 2010, A. Sultan, Korthalsella lindsayi , #10-006 [1]: 5 m 2nd, 1 1st; MK, Lake Tekapo, small island near Motuariki Island, 9 Jan 2010, A. Sultan, Korthalsella lindsayi , #10- 002a–c [3]: 5 F (4 mature + 1 young), 5 m 2nd.

Etymology: named after the host plant genus, Korthalsella .

Figures

FIGURE 8. Eriococcus korthalsellae Henderson sp. nov., adult female.

FIGURE 10. Eriococcus korthalsellae Henderson sp. nov., 2 nd-instar male nymph.