Pseudaulacaspis pyrrosiae, Hodgson, Chris J. & Łagowska, Bozena, 2011

Hodgson, Chris J. & Łagowska, Bozena, 2011, New scale insect (Hemiptera: Sternorrhyncha: Coccoidea) records from Fiji: three new species, records of several new invasive species and an updated checklist of Coccoidea, Zootaxa 2766, pp. 1-29 : 12-15

Pseudaulacaspis pyrrosiae sp. n.

( Fig. 4 )

Material examined. Holotype female: Fiji, Viti Levu, Suva, Thurston Gardens, on Pyrrosia adnescens (Polipodiaceae) , 14.vii.2009, C.J. Hodgson ( BMNH): 1/3adff (holotype arrowed, middle specimen, good).

Paratype females: remaining specimens on holotype slide plus 1/1adf (poor) + several exuviae; as previous but collected 24.vii.2009 ( BMNH): 1/4adff + 3 exuviae

Other material: Fiji, Viti Levu, Savura Forest Reserve, on maidenhair fern, 15.vii.2009, C.J. Hodgson #96 ( BMNH): 1/ 1pupa, 1st & 2nd exuviae; as previous, on Pteris sp., 24.vii.2009, C.J. Hodgson #51 ( BMNH): 1/2adff + 2 exuviae; Taveuni, Bouma, on maidenhair fern, 22.vii.2009, C.J. Hodgson #92 ( BMNH): 2/6adff + prepupa. ( BMNH; USDA). Also: Fiji, Suva, Adiantum fern, no date, F.P. Jepson No 46 ( BMNH): 1/7adff + 4 pread females (good – originally identified as Chionaspis dubia Maskell ); and Viti Levu, Nausori, maidenhair fern, 9.ix.1955, B.A. O’Connor 1363 ( BMNH, CIE 3691/14526): 3/4adff (fair to good).

Adult female

(Numerical data in brackets refers to the material collected by Jepson and O’Connor on maidenhair ferns).

Unmounted material. Scales collected from leaves of host plant. Scale test rather translucent when fresh but becoming whitish to silvery when dry, with exuviae at one end. Slide mounted specimens small, about 0.7–1.2 mm long; body elongate; pygidium rounded to slightly V-shaped; anterior margin of head mainly rounded; lateral lobes of free pygidial segments moderately produced; body membranous apart from pygidium.

Mounted material. Pygidium with medium lobes well developed, zygotic and with a pair of setae medially; each lobe with inner margin much longer than outer margin, forming a deep notch; inner margin serrated; posterior projection somewhat variable but usually slightly longer than 2nd lobes. Second lobes well developed, inner lobule much larger than outer lobule; 3rd lobes represented by serrations along the body margin. Gland spines large, arranged singly on pygidial segments V–VIII but with 1–4 (2–5) on segment IV, 2–4 (2–5) on III, usually 1 (1–5) on II and 0 (0–2) on I; anterior spines smallest; absent more anteriorly. Dorsum with large two-barred ducts about as wide as long, with totals (marginal + submarginal) of 2–6 (4–7) on segment V, 2–6 (2–7) on IV, 2–4 (4–6) on III and generally 0 but occasionally up to 3 (1–3) on II; plus 1–3 (1–2) submedial ducts on V, 1 or 2 (2 or 3) on IV, 0– 2 (0–3) on III and 0 on II. Smaller two-barred ducts, each about half size of larger ducts, present submarginally on segment III and each segment to mesothorax inclusive, as follows: mesothorax 4–7 (2–6), metathorax 3–5 (4–7), abdominal segment I 2–6 (3–5), II 3–6 (2–4), III 1–3 (1 or 2), IV 0. Microducts sparse, perhaps only present submedially on meso- and metathorax. Submarginal boss present on abdominal segment I. Anal opening situated towards base of pygidium.

Ventral surface with quinquelocular perivulvar pores in 5 elongate groups (posterio-lateral groups 11–19 (12– 22); medio-lateral groups 7–13 (12–19) and anterior group 3–7 (4–7) pores). Microducts present submarginally on abdominal segments III–VII and submedially on segments II and I and on each thoracic segment. Small two-barred ducts present submarginally on segment I and metathorax. Antennae each with 1 long seta. Anterior spiracles each with a group of 10–20 (10–17) trilocular pores; posterior spiracles without a group of pores.

Comment. Initially, it was thought that this species was P. coluisuvae Williams & Watson , but it differs in a few significant characters, namely (character-states for P. coluisuvae in brackets): (i) 2-barred ducts absent on head (present); (ii) margins of median lobes clearly serrated (poorly serrated); (iii) smaller anterior gland spines extend only to abdominal segment II (to the mesothorax); and (iv) each anterior spiracle with a group of more than 10 loculate pores (6–9). P. py r ro s ia e appears to be quite widespread on epiphytic ferns in Viti Levu. On both Pyrrossia and the other fern species, it was generally scattered and hard to detect, even though the test was translucent whitish. P. p y r ro s i a e is the same species as that listed by Lever (1945a) as P. dubia (Maskell) , which was collected on the fern Adiantum sp. and later listed as Phenacaspis dubia by Hinckley (1965). However, P. d u b i a is currently only known from New Zealand and differs from P. p y r ro s i a e in having (i) a group of gland spines near the anterior spiracles, and (ii) a group of trilocular pores by the posterior spiracles. Williams & Watson (1988a, p.17) also commented that the species were different.

Name derivation: this species is named after one of its host plants, Pyrrosia adnescens , an epiphytic fern belonging to the Polypodiaceae .

Key to adult female Pseudaulacaspis sp. known from Fiji (modified after Williams & Watson, 1988a).

1. Body turbinate, less than twice as long as wide. Each gland spine on pygidium with 2 or 3 microducts..................................................................................................... P. pentagona (Targioni)

- Body elongate, usually fusiform, more than twice as long as wide. Each gland spine on pygidium with 1 microduct........ 2

2. Submedium dorsal 2-barred ducts present on segment VI on pygidium. Head and prothorax often expanded laterally.......................................................................................... P. cockerelli (Cooley)

- Submedium dorsal 2-barred ducts absent from segment VI on pygidium. Head and prothorax gradually narrowing towards apex................................................................................................ 3

3. Smaller dorsal 2-barred ducts present as far forward as mesothorax..............................................4

- Smaller dorsal 2-barred ducts absent from mesothorax........................................................ 5

4. Single 2-barred ducts present on lateral angles of head plus a single duct on midline on head. Small gland spines present as far forwards as metathorax...................................................... P. coluisuvae Williams & Watson.

- Two-barred ducts absent from head. Small gland spines only extending as far forward as abdominal segment II................................................................................................... P. pyrrosiae sp. n.

5. Median lobes prominent, not forming a deep notch at apex of pygidium. Submarginal groups of 2-barred ducts on segment III numbering 3–5................................................................ P. samoana (Doane & Ferris)

- Median lobes forming a deep notch at apex of pygidium. Submarginal groups of 2–barred ducts on segment III numbering 1 or 2............................................................................ P. leveri Williams & Watson

Figures

FIGURE 4. Adult female Pseudaulacaspis pyrrosiae Hodgson & Łagowska, sp. n. Where A = small dorsal 2 - barred ducts; B = large dorsal 2 - barred ducts; C = dorsal view of posterior end of pygidium; D = ventral view of posterior end of pygidium; E = gland spine; F = variation in shape of median lobes; G = ventral microduct; H = ventral small 2 - barred duct; J = anterior spiracle, and K = antenna.