Coccus praetermissus, Cook, 2017

Cook, Lyn G., 2017, A newly recognised species that has been confused with the global polyphagous pest scale insect, Coccus hesperidum Linnaeus (Hemiptera: Coccomorpha: Coccidae), Zootaxa 4320 (3), pp. 571-591 : 585-586

Coccus praetermissus sp. n. Lin & Tanaka

( Fig. 3 )

urn:lsid:zoobank.org:act:68DA1396-37BF-4C1A-8126-562AE4CC1BFC

Material examined. Holotype. Adult female (ID: YPL00716). Australia: Queensland, Shelburne, Bramwell Junction, -12.09° S, 142.56° E, on Mangifera indica (Anacardiaceae) , 12.vii.2013, D. Pearce and L. Benson (ANIC: 1/1 female). GenBank accession numbers: 18S: MF594280 ; 28S: MF594316 ; COI: MF579677 ; EF-1α: MF594369 ; wingless: MF579618 .

Paratype. Adult female (ID: YPL00465). Malaysia: Kuala Lumpur, on Ixora chinensis (Rubiaceae) , 13.xii.2010, Y.-P. Lin (ANIC: 1/1 female). GenBank accession numbers: 18S: MF594278 ; 28S: MF594314 ; COI: MF579675 ; EF-1α: MF594367 ; wingless: MF579616 .

Paratype. Adult female (ID: YPL00732). Thailand: Ranong, on Rhizophora mucronata (Rhizophoraceae) , iv.2003, J. Offenberg (ANIC: 1/1 female). GenBank accession numbers: 18S: MF594281 ; 28S: MF594317 ; COI: MF579678 ; EF-1α: MF594370 ; wingless: MF579619 .

The three specimens from Taiwan, which are morphologically similar to Coccus praetermissus sp. n. but for which morphological measurements are not included in the species description, are as follows:

Adult female (ID: YPL00122). Taiwan: Suao Port, Suao, Yilan County, on Ficus irisana (Moraceae) , 7.ii.2009, Y.-P. Lin (ANIC: 1/1 female). GenBank accession numbers: 18S: MF594276 ; 28S: MF594312 ; COI: MF579673 ; EF-1α: MF594365 ; wingless: MF579614 .

Adult female (ID: YPL00291-1). Taiwan: Kenting National Park, Hengchuen, Pingtung County, on Calophyllum inophyllum (Clusiaceae) , 24.viii.2009, Y.-P. Lin (ANIC: 1/1 female). GenBank accession numbers: 18S: MF594277 ; 28S: MF594313 ; COI: MF579674 ; EF-1α: MF594366 ; wingless: MF579615 .

Adult female (ID: YPL00496). Taiwan: Chiayi City, on Podocarpus costalis (Podocarpaceae) , 24.viii.2009, Y.- P. Lin (ANIC: 1/1 female). GenBank accession numbers: 18S: MF594279 ; 28S: MF594315 ; COI: MF579676 ; EF- 1α: MF594368 ; wingless: MF579617 .

Other specimens examined that are considered to be Coccus praetermissus sp. n. are listed in Table 4.

Diagnosis. Adult females of Coccus praetermissus sp. n. can be identified by the following combination of morphological character states; (i) dorsal setae with blunt, rounded apices; (ii) dorsal tubular ducts, if present, situated around submarginal areas; (iii) anal plates together quadrate, with anterior margin subequal in length to posterior margin; (iv) antennae each with 7 segments; (v) ventral tubular ducts present on medial area near mesocoxae; (vi) each leg with a weak tibio-tarsal sclerosis. The only character of adult females that can be used to differentiate C. praetermissus sp. n. from C. hesperidum s. s. is the shape of the dorsal setae.

DNA sequence-based diagnoses (fixed differences between C. praetermissus sp. n. and C. hesperidum s. s., mapped to the GenBank reference sequence listed) are as follows:

18S: Reference sequence: Coccus hesperidum s. s. (ID: YPL00377): GenBank accession number: JX566904 . No fixed difference existed.

28S: Reference sequence: Coccus hesperidum s. s. (ID: YPL00377): GenBank accession number: JX627326 . Site# 120 (C), 141 (C), 165 (C), 180 (A), 186 (G), 201 (C), 593 (C).

COI: Reference sequence: Coccus hesperidum s. s. (ID: YPL00377): GenBank accession number: JX843723 . Site# 10 (T), 12 (A), 18 (T), 41 (G), 51 (C), 66 (A), 69 (C), 72 (C), 75–76 (CC), 79 (C), 87 (C), 99 (A), 105 (A), 108 (C), 114 (C), 133 (T), 135 (A), 138 (C), 147 (A), 151 (G), 165 (A), 174 (A), 186 (T), 213–214 (AC), 216 (T), 229 (C), 249 (C), 279 (A), 282 (T), 300–301 (AA), 309 (C), 318 (C), 324 (A), 327–328 (TT), 330 (A), 334 (T), 339 (T), 343 (C), 369 (C), 381 (A), 399 (T), 411–412 (TA), 415 (A), 427 (C), 432 (T), 447 (C), 456 (T), 460 (T), 477 (T), 480 (T), 489 (T), 507 (C), 513 (G), 516 (C), 528 (T), 537 (C), 543 (C), 561 (T), 579 (T).

EF-1α: Reference sequence: Coccus hesperidum (ID: YPL00377): GenBank accession number: MF594326 . Site# 18 (C), 99 (G), 105 (G), 114 (T), 121 (T), 160 (G), 162–166 (-), 184 (T), 199 (G), 241 (T), 298 (T), 326 (T), 334 (G), 355 (T), 391 (G), 394 (C), 427 (C), 443 (A), 453 (A), 456–457 (CC), 462 (T), 464–467 (ATTG), 471 (A), 477 (C), 492 (G), 498 (G), 503 (T).

wingless: Reference sequence: Coccus hesperidum (ID: YPL00377): GenBank accession number: MF579635 . Site# 174 (T), 192 (C), 207 (A), 306 (G).

Description. Adult female ( Fig. 3 ): description based on three specimens, each on a separate slide, the holotype (YPL00716) in good condition and two paratypes (YPL00465 and YPL00732) in fair condition.

Slide-mounted material. Body elongate oval, 3.0– 3.8 mm long, 1.5–3.0 mm wide, margin with a shallow indentation at each stigmatic cleft; anal cleft 1/5–1/7 body length.

Dorsum. Derm membranous throughout when young. Dermal areolations well developed in old females, indicating slight sclerotisation. Dorsal setae frequent throughout, relatively short and with blunt apices, each 5–10 µm long, 1–1.5µ wide on shaft with a well-developed basal socket. Preopercular pores small, 3–4 µm in diameter, barely sclerotised, present in diffuse group of 4–17 pores anterior to anal plates. Dorsal tubular ducts each with a thin outer ductule, shallow cup-shaped invagination, and fine inner ductule with a small terminal gland, found only on submarginal areas of abdomen. Dorsal microducts relatively evenly and sparsely distributed throughout dorsum. Dorsal tubercles present submarginally, each tubercle simple; with 1 pair on head, 0 or 1 pair between stigmatic clefts, 0 or 1 pair on abdomen. Anal plates together quadrate, with anterior margin 90–105 µm and posterior margin 93–108 µm long; each plate with well-developed supporting bar and 4 fine apical setae; length of plates 130–203 µm; maximum width of single plate 70–87 µm. Ano-genital fold with 2 or 3 pairs of setae along anterior margin and 2 or 3 pairs laterally. Anal ring bearing 6 setae. Eye spot present on margin.

Margin. Marginal setae spinose, each 12–51 µm long, with a well-developed basal socket and typically with a fimbriate apex but can appear pointed; 10–18 setae present on each side between stigmatic clefts; 38–45 setae on head between anterior stigmatic clefts of each side; 24–38 setae on each side of abdomen posterior to posterior stigmatic cleft. Stigmatic clefts shallow but indented, each cleft containing 3 stigmatic spines, median spine much the longest, 40–55 µm long, about 3–4 times as long as a lateral spine.

Venter. Derm entirely membranous. Pregenital disc-pores each with 9–11 loculi (mostly 10), present around genital opening and medio-lateral area of preceding two segments. Spiracular disc-pores each with 5 loculi, present between margin and each spiracle in band 1–3 pores wide; anterior bands each containing 13–33 pores, posterior bands each containing 16–41 pores. Ventral microducts relatively evenly and sparsely distributed throughout venter; 0 or 1 preantennal pores present near base of each antenna. Ventral tubular ducts of one type, each with long narrow outer ductule, fine inner ductule and well-developed terminal gland; present in medial area near mesocoxae in a group of 2 or 3. Ventral setae: with 3 pairs of long pregenital setae and 1–3 pairs of long setae between antennae; other setae short and fine. Spiracles each composed of a sclerotised, funnel-shaped outer peritreme, which leads through spiracular opening into tracheae; width of each peritreme: in anterior spiracle 30–45 µm, posterior 38–59 µm. Legs well developed, each with small tibio-tarsal articulation and small articulatory sclerosis; claw without denticle; both claw digitules rather broad and slightly shorter than thin tarsal digitules; trochanter + femur 148–191 µm, tibia 82–132 µm, and tarsus 67–100 µm. Antennae each with 7 segments; total length 230–357 µm. Labium approximately 71–118 µm wide, 135–165 µm long.

Etymology. The species epithet praetermissus is Latin for "overlooked", and refers to the specimens of this species having long been considered conspecific with Coccus hesperidum s. s.

Remarks. Coccus praetermissus sp. n. is morphologically very similar to C. hesperidum and it might be difficult to distinguish them if good slide mounts of adult females are not available. Therefore, we recommend that both morphological (having dorsal setae with blunt apices) and molecular (COI DNA) data should be used when an authoritative identification is required.

Among the examined slides labelled/identified as “ Coccus hesperidum ” deposited in the BMNH, there are five with a manuscript name from E.E. Green on the labels, “ Lecanium holosericeae ” (citation of this manuscript name here is not intended to be for nomenclatural purposes; it is not an available name). These specimens were collected in Darwin (Northern Territory, Australia) on Acacia holosericea by G.F. Hill on 3.xi.1915. They are morphologically indistinguishable from C. praetermissus sp. n., having dorsal setae with bluntly rounded apices (noted on one slide label in D.J. Williams’s handwriting as “cylindrical setae”). Dr D.J. Williams mounted some specimens from this sample in Green’s collection (seven slides) and identified them as C. hesperidum on 30.iii.1954. Green’s manuscript name was never published.

Figures

FIGURE 3. Adult female of Coccus praetermissus Lin & Tanaka, sp. n. ANT: antenna; AP: anal plate; DA: dorsal areolations; DMD: dorsal microduct; DS: dorsal seta; DT: dorsal tubercle; DTD: dorsal tubular duct; LG: leg; MP: multilocular pore; MS: marginal setae; PAP: preantennal pore; POP: preopercular pores; SP: spiracular pore; SSP: stigmatic spines; VMD: ventral microduct; VTD: ventral tubular duct. Scale bars: 200 µm for ANT, AP; 100 µm for DA, LG; 50 µm for SSP; 10 µm for other details.