Acanthococcus dennoi Miller and Miller

Miller, Douglass R. & Stocks, Ian C., 2022, New genera and species of felt scales (Hemiptera: Coccomorpha: Eriococcidae), with descriptions of new species and immature instars of described species, Zootaxa 5221 (1), pp. 1-213 : 17

Acanthococcus dennoi Miller and Miller rev. comb.

Acanthococcus dennoi Miller and Miller 1993: 27 .

Eriococcus dennoi (Miller & Miller) ; Miller and Gimpel 1999: 213 (change of combination).

Specimens examined: material not reported previously: UNITED STATES: Georgia: Bryan Co.: no specific locality, IX-17-1974, on Spartina patens, R.J. Beshear (2 first-instar nymphs on 2 slides) USNM . South Carolina: Charleston Co.: Isle of Palms , IX-15-1963, on Spartina sp. grass, J.T. Rogers (37 first-instar nymphs on 1 slides) USNM.

Etymology: The species epithet “ dennoi ” was named in honor of the late Robert F. Denno, Department of Entomology, University of Maryland, USA, who collected this and many other interesting scale insects.

First-instar nymph ( Fig. 5 )

Description: Slide-mounted specimens 0.5–0.7 mm long, 0.2–0.3 mm wide. Body pear-shaped, with protruding anal lobes. Anal lobes apically rounded; each lobe dorsally with 3 apically acute enlarged setae, posteromedial seta largest, lateral seta smallest, microtubular ducts absent; each lobe ventrally with 3 flagellate setae including suranal seta and anal-lobe seta.

Dorsum without flagellate setae. Enlarged setae arranged in 3 pairs of longitudinal lines (medial, mediolateral and sublateral), in transverse rows from head to segment VII; of 2 sizes: larger setae on head and anal lobes with acute apices; smaller size over remainder of surface with acute apices; largest enlarged setae 16–19 μm long, largest seta on head 14–18 μm long; largest small-sized setae 7–8 μm long; with 8 setae on segment IV. Microtubular ducts each about 3 μm long, forming 1 pair of irregular longitudinal lines on mediolateral area of head, thorax and abdomen. Macrotubular ducts, cruciform pores, and multilocular pores absent. Microtrichia present on abdomen.

Anal ring ventral or apical, with 3 setae on each side of ring, suranal setae flagellate. Anal tube without sclerotization, with anal flap.

Venter with setae flagellate, longest seta on segment II approximately 13 μm long, on segment VII about 11 μm; longest anal-lobe seta 130 μm long. Enlarged setae absent. Macrotubular ducts and microtubular ducts absent. Multilocular pores of 3 kinds: 9-locular pores, if present, located near spiracles; 7-locular pores most abundant on thorax; 5-locular pores most abundant on abdomen. Cruciform pores restricted to thorax, with 2 or 3 pores along each thoracic body margin. Legs without pores; each femur with 5 setae, 3 distal and 2 proximal; each tibia with 4 setae; hind tibia/tarsus 0.7–0.8. Claw without denticle near tip. Antennae each 6-segmented, about 95 μm long. Without frontal lobe. Preantennal pore present. Microtrichia present on abdomen, absent from coxae.

Notes: The description is based on 29 specimens from two localities. Of the seven Acanthococcus species treated in this publication, the first-instar nymph of Ac. dennoi is most similar to the first-instar nymph of Ac. pennyae in having four setae on each hind tibia, five setae on each hind femur, and dorsomedial enlarged setae usually about same size as lateral setae. They differ as follows (character states in brackets are of Ac. dennoi ): the predominant multilocular pore on the ventral abdomen with 3 loculi (5 loculi); cruciform pores absent (present).

Figures

FIGURE 5. Acanthococcus dennoi Miller and Miller 1993, first-instar nymph, Richmond Hill State Park, Bryan Co., Georgia, USA, September 17, 1974, on Spartina patens. R.J. Beshear. A=enlarged seta; D=5-locular pore; F=microtubular duct; H=cruciform pore.