Tanyscelis tripocula Hardy & Gullan

Hardy, Nate B. & Gullan, Penny J., 2010, Australian gall-inducing scale insects on Eucalyptus: revision of Opisthoscelis Schrader (Coccoidea, Eriococcidae) and descriptions of a new genus and nine new species, ZooKeys 58, pp. 1-74 : 36-39

Tanyscelis tripocula Hardy & Gullan sp. n. Figs 3f21

Gall

(Fig. 3f). Female. On leaf. Gall circular, 3-4 mm diameter, almost level with leaf surface on orifice side, a slightly raised bump on opposite leaf surface; opening round to elongate, surrounded by raised ring of tissue, usually opening on adaxial (upper) surface of leaf. Gall tissue green but highly glaucous due to white waxy exudation on Eucalyptus cephalocarpa ; gall not glaucous and becoming brown with age on Eucalyptus aromophloia .

Male. On leaf, usually opening on adaxial surface. Similar to galls of females; gall surface glaucous if on Eucalyptus cephalocarpa but gall tissue red, appearing purplish due to white wax covering.

Adult female

(Fig. 21) (n = 16). Body outline circular, abdomen tapered and curved dorsad in mature females, vulva and anal opening topologically dorsal, length 1.2-2.4 mm, greatest width 1.1-2.2 mm. Eyes each 28-48 µm wide, on dorsal margin. Antennal segmentation poor, each antenna appearing 3-segmented, 60-240 mm long. Frontal lobes each 170-340 µm long, 115-290 µm wide. Tentorial box 170-350 mm long. Labium 80-130 mm long, 85-120 mm wide. Pump chamber 18-23 µm long, 25-28 µm wide. Spiracles 80-175 mm long, 40-90 mm wide across atrium. Fore and mid legs small stumps, some segmentation apparent, 50-110 µm long. Hind leg with coxa 285-340 µm long, trochanter + femur 420-490 µm long, tibia slightly curved, outer margin concave, 305-410 µm long, tarsus 160-230 µm long; translucent pores dense on both surfaces of hind tarsus, tibia and all but proximal end of femur; trochanter with 2 campaniform sensilla on each side; femur-tibia articulation functional; claw and digitules present but reduced. Anal opening 8-25 µm wide, an irregular slit on dorsal body surface, surrounded by rugose sclerotic plate 40-73 µm wide; a few setae may be associated with plate, but without pores.

Dorsum. With medial sclerotic shield composed of crowded nodules separated by deep fissures, with a larger deep invagination at posteromedial margin of each thoracic segment. Derm outside of shield membranous, densely beset with minute nodules. Dorsal setae flagellate, 8-50 mm long, in a transverse row across each abdominal segment, scattered over head and thorax. Macrotubular ducts absent. Microtubular ducts absent. Quinquelocular pores 7-9 µm in diameter, restricted to abdominal segment VIII and lateral areas of VII.

Venter. Mature female with venter expanded relative to dorsum, so ventral body margin appears topologically dorsal. Oral lobes membranous. Setae flagellate, 8-100 mm long, a scant few on abdomen, anterior to mid legs, and along margin. Macrotubular ducts absent. Quinquelocular pores similar to those on dorsum, reasonably numerous in a band radiating from each spiracle to body margin, also a few in transverse band on each of abdominal segments V–VIII.

Material examined.

Holotype (here designated): AUSTRALIA: Victoria: 1 adult female (1.35 mm long, 1.17 mm wide): ex flat, circular gall on leaf, Eucalyptus cephalocarpa , Macclesfield, Kirkpatrick’s Road, ca 300 m W of Short Road, -37.87°; 145.47°, 8 Feb., 2005, PJG and NBH, NH78 (ANIC).

Paratypes: AUSTRALIA: Victoria: 7 adult females, 4 second-instar female, 10 adult males, 2 pupal males: same data as holotype (ANIC); 5 adult females: ex galls, Eucalyptus cephalocarpa , Macclesfield, Kirkpatrick Road, 17 July, 1976, PJG (ANIC); 7 adult females: ex galls, Eucalyptus cephalocarpa , Macclesfield, Kirkpatrick Road, 17 Oct., 1977, M. Hill (ANIC except 1 adult female BMNH, 1 adult female NMV, 1 adult female USNM); 2 adult females (1 parasitised), 3 second-instar females, 1 first-instar nymph: ex leaf gall, Eucalyptus cepahalocarpa , Cranbourne, Royal Botanic Gardens Cranbourne, -38.14°; 145.28°, 9 Feb., 2005, PJG (ANIC).

Additional material:

AUSTRALIA: Victoria: 9 adult females: ex leaf gall, Eucalyptus aromaphloia , Grampians, Victoria Valley, 400 m NW of Beehive Track, ca 1 km along Beehive Track from Serra Road, 17 Nov., 1976, PJG (ANIC); 6 adult females: ex leaf galls, Eucalyptus aromaphloia , Grampians Nat. Park, Victoria Valley, Glenelg River Road, W of Moora Moora Reservoir, -37.23°; 142.41°, 6 Feb., 2005, PJG and NBH, NH31, NH78 (ANIC).

Comments.

Adult females of Tanyscelis tripocula can be recognised easily by possessing a dorsal shield composed of sclerotic nodules separated by deep fissures and having a deep invagination at the posteromedial margin of each thoracic segment. Also distinctive are (1) the manner in which the posterior abdominal segments are directed dorsally in mature females (not in young adult females); (2) the shape of the anal opening, which is an irregular slit in a rugose sclerotic plate; and (3) the complete absence of tubular ducts. The phylogenetic position of Tanyscelis tripocula , as sister to all other species of Tanyscelis based on DNA data (NBH, unpublished data),is not well supported.

Galls of females on Eucalyptus cephalocarpa are smaller, flatter and glaucous compared with those on Eucalyptus aromaphloia . The adult females from galls on Eucalyptus cephalocarpa are smaller and less sclerotised than the females from Eucalyptus aromaphloia , but this may be an age effect. The type series has been restricted to specimens from Eucalyptus cephalocarpa because of the above slight differences.

Adult males were observed by PJG emerging from their galls on Eucalyptus cephalocarpa in early February 1979. They emerged head first from the gall opening, which was plugged by male’s first-instar exuviae until gall maturity. The males were capable of short jumps of 1-3 cm either forwards or backwards, as well as weak flight. Adult females also may bear their first-instar exuviae on their dorsum.

Etymology.

The species name is derived from the Latin word poculum, meaning cup and tres or tri- mean three. It refers to the three deep invaginations along the dorsal midline. It is a noun in apposition.