Acropygorthezia williamsi LaPolla & Miller, 2008

Lapolla, John S., Burwell, Chris, Brady, Seán G. & Miller, Douglass R., 2008, A new ortheziid (Hemiptera: Coccoidea) from Australia associated with Acropyga myops Forel (Hymenoptera: Formicidae) and a key to Australian Ortheziidae, Zootaxa 1946, pp. 55-68 : 58-66

Acropygorthezia williamsi LaPolla & Miller , n. sp.

Field Appearance. In alcohol . Specimens egg or bean-shaped; white; without wax; legs and mouthparts yellowish brown; antennae short and stub like; anal ring darker than legs, yellowish brown, located dorsally near center of abdomen; vulva large, located near posteroventral end of abdomen, some specimens with vulva stretching laterally across body; dorsal and ventral segmentation often visible.

Mounted adult female ( Fig. 1) (based on 10 specimens). Holotype adult female 0.99 mm long (paratypes 1.23–1.71 mm); holotype 0.76 mm wide (paratypes 0.93–1.25 mm). Antennae 2-segmented, holotype 60 µm long (paratypes 55–77 µm); apical segment with 2 enlarged setae, 2 filamentous setae, and 1 basiconic sensillum; basal segment without setae (paratypes sometimes with 1 seta).

Venter. Labium truncate apically, holotype with medial and apical segments combined 125 µm long (paratypes 127–156 µm), basal segment with 1 pair of setae, medial segment with1 pair, apical segment with 6 pairs (paratypes 5–6 pairs). Legs elongate, hind leg of holotype about 460 µm long (paratypes 593–642 µm), hind trochanter+femur of holotype 180 µm long (paratypes 169–224 µm), tibia+tarsus of holotype 204 µm long (paratypes 237–274 µm); claw of holotype 63 µm long (paratypes 61–77 µm), legs with rows of conspicuous setae, some of setae on outer margin of trochanter+femur and tibia+tarsus apically capitate. Spines on body of 2 sizes: longer spines in medial areas surrounding legs, less dense than marginal spines; shorter spines unusually abundant in submarginal and marginal areas. Setae of 2 types: filamentous setae scattered in small numbers over surface, dome-shaped setae scattered over surface but most abundant on submargin and margin. Quadrilocular pores protruding from derm, of 2 sizes; larger size in medial areas between legs, smaller size in marginal areas. Small sclerotized pores present in marginal areas.

Dorsum. Spines, 10–15 µm long, unusually abundant over surface, present everywhere except in intersegmental areas and in anal area. Setae present in small numbers along body margin and in segmental rows, longest about 20 µm long. Quadrilocular pores of small size only, arranged in 3 pairs of longitudinal lines (lateral, mediolateral, and medial). Small sclerotized pores scattered over surface. Anal ring without obvious opening. Abdominal spiracles inconspicuous, 7 pairs in submarginal areas from segments I to VII, with sclerotized vestibule.

Mounted third-instar nymph (based on 1 specimen). Same as adult female except as follows. Body 1.29 mm long; 0.87 mm wide. Antennae 60 µm long.

Venter. Labium with medial and apical segments 135 µm long. Hind leg 545 µm long, hind trochanter+femur 190 µm long, tibia+tarsus 240 µm long; claw 65 µm long.

Mounted second-instar nymph (based on 6 specimens). Same as adult female except as follows. Body 0.78–1.10 mm long; 0.65–93 mm wide. Antennae 40–50 µm long.

Venter. Labium with medial and apical segments 130–135 µm long. Hind leg 440–505 µm long, hind trochanter+femur 175–185 µm long, tibia+tarsus 215–230 µm long; claw 55–62 µm long.

Notes: For differences between third and second-instar nymphs see discussion below.

Mounted first-instar nymph ( Fig. 2) (based on 9 specimens). Body 0.64–0.93 mm long; 0.51–0.76 mm wide. Antennae 2-segmented, 46–48 µm long; apical segment with 2 enlarged setae, and 1 filamentous seta; basal segment without setae.

Venter. Labium 3 segmented, with apex slightly rounded or truncate, medial and apical segments 109–126 µm long, basal segment with 1 pair of setae, medial segment with1 pair, apical segment with 6 pairs. Legs elongate, hind leg 426–437 µm long, hind trochanter+femur 140–160 µm long, tibia+tarsus 170–210 µm long; claw 56–60 µm long, legs with rows of conspicuous setae, some of setae on outer margin of trochanter+femur and tibia+tarsus apically capitate. Spines of 2 sizes: longer spines in medial areas surrounding legs, less dense than marginal spines; shorter spines unusually abundant in submarginal and marginal areas. Setae of 2 types: filamentous setae scattered in small numbers over surface, dome-shaped setae scattered over surface but most abundant on submargin and margin. Quadrilocular pores protruding from derm, of 1 size; present in medial areas between legs and in marginal areas. Small sclerotized pores apparently absent.

Dorsum. Spines unusually abundant over surface, present everywhere except in intersegmental areas and in anal area, 12–18 µm long. Setae, longest 7–15 µm long, present in small numbers along body margin and in segmental rows. Quadrilocular pores scattered over surface of abdomen. Small sclerotized pores apparently absent. Anal ring without obvious opening. Abdominal spiracles apparently absent.

Notes: Characteristics of the first instar of this species that are atypical of other scale insects are: the presence of numerous spines, reduced antennae, an anal ring that is located in the middle of dorsum that lacks setae and pores, and fused tibia and tarsus.

Mounted adult male ( Fig. 3) (based on 3 specimens). Body 1.10–1.16 mm long; 0.95–0.98 mm wide. Antennae 2-segmented 112–120 µm long; apical segment with 2 enlarged setae, 10–12 filamentous setae, and with or without basiconic sensillum; basal segment without setae.

Venter. Mouthparts reduced and non-functional. Legs elongate; hind leg 688–701 µm long; hind trochanter+femur 258–260 µm long; tibia+tarsus 303–304 µm long; claw 47–49 µm long; legs with rows of conspicuous setae, some of setae on outer margin of trochanter+femur and tibia+tarsus apically capitate. Spines of 2 sizes: longer spines in medial areas surrounding legs, less dense than marginal spines; shorter spines unusually abundant in submarginal and marginal areas. Setae of 2 types: filamentous setae scattered in small numbers over surface, dome-shaped setae scattered over surface but most abundant on submargin and margin. Quadrilocular or discoidal pores present near thoracic spiracles. Small sized pores present near posterior margin of abdomen. Penial sheath hinged near posterior apex of abdomen, ventral part of penial sheath 497–532 µm long; 176–179 wide µm long (measured at widest point at base); aedeagus 785–857 µm long; aedeagus annulated except towards base where it appears more heavily sclerotized.

Dorsum. Spines unusually abundant over surface, present everywhere except in intersegmental areas and in anal area, 6–10 µm long. Setae present in small numbers along body margin and in segmental rows, longest about 21 µm long. Quadrilocular pores absent. Small sclerotized pores and small clear pore present posteriorly. Anal ring well developed but without pores, setae, or obvious opening. Abdominal spiracles inconspicuous, 6 pairs in submarginal areas from segments I to VI, with sclerotized vestibule. Penial sheath not visible from dorsum.

Notes: The genital structure is quite unusual in that it is strictly ventral and is hinged near the base of the abdomen so that it does not protrude posteriorly. Another characteristic that is atypical of male scales is that the anal ring appears to be well developed and the anus may be functional.

Mounted pupal male ( Fig. 4) (based on 2 specimens). Body 1.07 and 1.20 mm long; 0.88 and 0.89 mm wide. Antennae 2-segmented, about 75 µm long; apical segment with 2 enlarged setae, 2–4 filamentous setae, and 0–1 basiconic sensillum; basal segment with or without 1 seta.

Venter. Mouthparts reduced and non-functional. Legs elongate, hind leg 556 and 557 µm long, hind trochanter+femur 174 and 210 µm long, tibia+tarsus 243 and 269 µm long; claw about 51 µm long, legs with rows of conspicuous setae, all appear apically acute. Spines of 2 sizes: longer spines in medial areas surrounding legs, less dense than marginal spines; shorter spines unusually abundant in submarginal and marginal areas. Setae of 2 types: filamentous setae scattered in small numbers over surface, dome-shaped setae scattered over surface but most abundant on submargin and margin. Quadrilocular pores and small sclerotized pores apparently absent. Genital area primarily ventral, with triangular ventral lobe and apically acute penial sheath; ventral lobe 118 and 131 µm long, about 132 µm long; penial sheath 165 and 170 µm long, about 178 µm wide.

Dorsum. Spines unusually abundant over surface, present everywhere except in intersegmental areas, genital region, and anal area, about 5 µm long. Setae present in small numbers along body margin and in segmental rows, longest about 10 µm long. Quadrilocular and small sclerotized pores apparently absent. Anal ring without obvious opening. Abdominal spiracles inconspicuous, apparently with 6 pairs in submarginal areas from segments I to VI, with sclerotized vestibule.

Notes: Many features are difficult to see, especially the spiracles, pores, and segmentation. It is possible that quadrilocular pores are present, but are confused with broken setal bases, and that there is 1 more pair of spiracles. Characteristics of the pupa of this species that are atypical of those of other scale insects are the presence of well-developed legs and the anal structure.

Mounted prepupal male ( Fig. 5) (based on 2 specimens). Body 1.56 and 1.19 mm long; 0.92 and 0.95 mm wide. Antennae 2-segmented, 62 and 59 µm long; apical segment with 2 enlarged setae, 2–4 filamentous setae, and apparently without basiconic sensillum; basal segment with or without 1 seta.

Venter. Mouthparts reduced and non-functional. Legs elongate, hind leg 513 and 528 µm long, hind trochanter+femur 196 and 181 µm long, tibia+tarsus 251 and 236 µm long; claw 54 and 58 µm long, legs with rows of conspicuous setae, setae on outer margin of tibia slightly capitate. Spines of 2 sizes: longer spines in medial areas surrounding legs, less dense than marginal spines; shorter spines unusually abundant in submarginal and marginal areas. Setae of 2 types: filamentous setae scattered in small numbers over surface, domeshaped setae scattered over surface but most abundant on submargin and margin. Quadrilocular pores or discoidal pores located near thoracic spiracles; small sclerotized pores apparently absent. Genital area ventral, with central conical area and outer flat area with few sensilla on conical area.

Dorsum. Spines unusually abundant over surface, present everywhere except in intersegmental areas, genital region, and anal area, about 10 µm long. Setae present in small numbers along body margin and in segmental rows, longest about 10 µm long. Quadrilocular and small sclerotized pores apparently absent. Anal ring without obvious opening. Abdominal spiracles inconspicuous, apparently with 7 pairs in submarginal areas from segments I to VII, with sclerotized vestibule.

Notes: Many features are difficult to see, especially the abdominal spiracles, abdominal segmentation, and pores. Characteristics of the prepupa of this species that are atypical of those of other scale insects are the presence of well-developed legs and the anal structure.

Material examined. Holotype: Adult female mounted on slide with 3 paratype adult females; a map is given on the label of position of holotype on slide, AUSTRALIA, Queensland, Bulimba Creek, Carindale , Brisbane , 27° 30’ 02.09” S, 153° 06’ 32.09”E, patch of dry forest, under small log in nest of Acropyga myops , VIII-2006, C. Burwell, SGB1061 ( QMBA) . Paratypes: 19 adult females, 1 third-instar female, 4 secondinstar nymphs, 4 first-instar nymphs from same locality and date as holotype; also 3 first-instar nymphs , 4 adult males, 2 pupae, and 2 prepupae from same locality but collected 14-II-2008 ( ANIC, BMNH, QMBA, BME, USNM) ; 6 adult females, 2 second-instar nymphs, 2 first-instar nymphs from AUSTRALIA, Queensland, Chelsea Road Bushland Reserve, Ransome, Brisbane , 27° 29’ 01.4”S, 153° 10’ 54.1”E, VIII-2006, C. Burwell, SGB1063 ( ANIC, QMBA, USNM) .

Etymology. The generic name Acropygorthezia is a feminine noun and is a combination of the names of the attending ant, Acropyga , and the scale suffix Orthezia . The species epithet is given to honor Dr. Douglas J. Williams (Natural History Museum, London), for his numerous contributions to the systematics of mealybugs associated with ants. His works serve as the foundation of our knowledge on the mealybug aspects of the fascinating interactions between pseudococcids and ants.