Oacoccus nothofagi, Williams, 2007

Williams, D. J., 2007, Scale insects of the families Asterolecaniidae and Eriococcidae (Hemiptera: Coccoidea) in New Caledonia, Journal of Natural History 41 (21 - 24), pp. 1343-1366: 1348-1350

publication ID

http://doi.org/ 10.1080/00222930701425498

persistent identifier


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scientific name

Oacoccus nothofagi

sp. nov.

Oacoccus nothofagi   sp. nov.

( Figure 1 View Figure 1 )


External appearance covered in a thin greyish waxy scale with raised brownish centre, resembling scale cover of many Diaspididae   but without exuviae; on twigs and woody petioles.

Adult female on microscope slide almost circular, 1.40–1.55 mm long, 1.30–1.45 mm wide, posterior end with a cleft, forming apparent anal lobes; base of cleft dorsally with an oval to semicircular sclerotized area, plate-like, 165–190 Mm wide, 120–125 Mm long, entire, except divided at posterior edge to almost half its length by a narrow parallel cleft about 55 Mm long, forming a pair of true anal lobes each with a stiff apical seta 20–35 Mm long, inner end of cleft rounded enclosing anal ring. Anal ring cellular, 15–17 Mm in diameter composed of two outer semicircular plates joined at anterior edge by a narrow rim, with six setae, each 30–40 Mm long, reaching nearly to anal lobes. Dorsal body margin with a continuous series of finger-like extensions, inwardly projected, 60–110 Mm long, each swollen at base on margin and usually with a single microduct about 25–35 Mm long, 1.0 Mm wide, between each pair, opening on margin. Antennae normally six-segmented, 110–120 Mm long, segments 2–6 all about same width, segment 3 longest; all segments with a few short flagellate setae about 10 Mm long, except on terminal segment where some about 20 Mm long; also a single seta at apex about 40 Mm long. Last two segments also with fleshy setae about 10 Mm long. Legs well developed but small and slender; mesothoracic and metathoracic legs situated well posterior on lower half of body; hind coxa 25–30 Mm long, hind trochanter + femur 80–87Mm long, hind tibia + tarsus 70–75 Mm long. Claw about 10 Mm long without a denticle but with two disparate knobbed digitules, one much more expanded apically than other. Distal trochanteral seta about 25 Mm long; translucent pores absent from hind coxa; hind tarsus with two outer and two inner short setae each about 10 Mm long. Ratio of hind tibia + tarsus to hind trochanter + femur 0.80–0.88. Ratio of lengths of hind tibia to hind tarsus 0.50–0.55. Mouthparts situated about one-quarter distance of body from anterior head margin. Labium 30–35Mm long, apparently two-segmented with four short setae at apex. Clypeolabral shield longer than labium; pharynx noticeably long and easily visible when stained. Spiracles each about 30 Mm long, metathoracic spiracles situated on posterior half of body about one-quarter distance from apex of abdomen.

Dorsum without apparent segmentation, with minute setae, each scarcely 5.0 Mm long, a few present on sclerotized area and on medial areas of dorsum, others sparse around submargins.

Ventral surface with abdomen displaced towards posterior end of body, segmented in medial area with a few short setae each about 10 Mm long. Other setae about 35–40 Mm long, present between antennal bases. Remainder of body without setae and ducts but with minute quinquelocular pores, each about 2.0 Mm in diameter, on abdominal segment VIII and extending in two oblique rows to areas around metathoracic spiracles.

First-instar nymph

Description. Described from embryos only. Body broadly oval with poorly developed anal lobes each with an apical seta about 20 Mm long. Anal ring situated at base of anal lobes, cellular, about 12.5 Mm in diameter, almost U-shaped, consisting of two outer sclerotized plate-like areas joined anteriorly by a narrow rim; with six setae each about 25 Mm long surpassing anal lobes in length. Dorsal surface of body with a continuous series of fingerlike processes extending inwards. A single microduct present between each pair of processes, opening on margin as in adult female. Dorsal surface with submarginal setae, each minute and stiff, and with a submedial series of similar setae. Ventral surface with minute quinquelocular pores extending anteriorly from near base of anal lobes in two oblique rows to metathoracic spiracles as in adult female. Antennae six-segmented. Legs normal; claw slender, apparently without a denticle.

Material examined

Holotype: adult ♀, New Caledonia, Mt Do , 1000 m, on twigs and woody petioles of Nothofagus codonandra   , 22 October 1978 (coll. J. S. Dugdale), No. 23 ( NZAC)   . Paratypes: New Caledonia, same data as holotype, one adult ♀ ( NZAC)   , two adult ♀♀ ( BMNH)   , one adult ♀ ( USNM)   , one adult ♀ ( IANC)   .


The name is based on the name of the plant genus Nothofagus   in the Latin genitive meaning of or from.


New Zealand Arthropod Collection


Smithsonian Institution, National Museum of Natural History