Acanthococcus coccineus (Cockerell)

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 : 15-17

Acanthococcus coccineus (Cockerell) rev. comb.

Eriococcus coccineus Cockerell 1894a: 204 .

Eriococcus coccineus lutescens Cockerell 1894a: 204 (junior synonym discovered by Ferris 1955: 116).

Eriococcus saboteneus Kuwana and Tanaka 1922: 215‒221 (junior synonym discovered by Kozár et al. 2013: 432).

Nidularia coccinea (Cockerell) ; Lindinger 1933a: 108 (change of combination requiring emendation of specific epithet for agreement in gender).

Acanthococcus coccineus (Cockerell) ; Miller and Miller 1992: 19–22 (change of combination).

Rhizococcus coccineus (Cockerell) ; Kozár 2009: 106 (change of combination).

Acanthococcus coccineus (Cockerell) ; Hodgson and Miller 2010: 99–100 (revived combination; previously published).

Rhizococcus coccineus (Cockerell) ; Kozár, Kaydan, Konczné Benedicty and Szita 2013: 432 (revived combination; previously published).

Specimens examined: UNITED STATES: Maryland: Prince Georges Co.: Beltsville, in greenhouse, VI-3-1977, on Mammillaria sp. , J. Tassone (6 first-instar nymphs on 2 slides) USNM. New York: Bronx County, The Bronx, VIII-31-1944, on Mammillaria sp. and Harrisia sp. , G. Rau (42 first-instar nymphs on 1 slide) USNM. Texas: El Paso Co.: El Paso, IV-29-1925, on cactus, T.A. Arnold (42 first-instar nymphs on 1 slide) USNM; El Paso, X-12-1926, on Neomammillaria sp. , T.A. Arnold (27 first-instar nymphs on 1 slide) USNM.

Etymology: The species epithet “ coccineus ” is formed from the Latin word “ coccineus ” meaning “scarlet” or “red like a berry” and probably refers to the red color of this species under certain circumstances.

Notes: Based on the synonymy given above, it is clear that generic assignments of species within the Eriococcidae are sometimes confused. Kozár et al. (2013) distinguished adult females of Acanthococcus species from adult females of Rhizococcus species as follows (character states of Acanthococcus are in brackets): hind tibiae each with five setae (four) and microtubular ducts short (long). Koteja (1974) also indicated that Acathococcus (=Acanthococcini) differs from Rhizococcus (= Rhizococcus group), with the former having eight pairs of setae on the labium while the latter has nine. Examination of these character states in the publication by Kozár et al. (2013) shows considerable incongruence. For example (the generic character state is given in brackets), R. brevenniae ( Goux 1993) has eight pairs of labial setae (nine), Ac. altaicus Matesova 1967 (= Ac. spiraeae Borchsenius 1949 ) has nine pairs (eight), Ac. isacanthus Danzig 1975 has nine pairs (eight), R. heteroacanthus ( Balachowsky 1927) has four tibial setae (five), Ac. latialis ( Leonardi 1907) has five tibial setae (four), and there is some overlap in the microtubular duct lengths. We here consider these character states to be useful in species-level diagnoses, but, until more detailed analyses can be undertaken on the classification of eriococcid genera, we are reinstating the assignment of this species to the widespread genus Acanthococcus .

First-instar nymph ( Fig. 4 )

Description: Slide-mounted specimens about 0.5 mm long, 0.2–0.3 mm wide. Body slightly pear-shaped, with protruding anal lobes. Anal lobes narrow, apically acute, lightly sclerotized; each lobe dorsally with 3 enlarged setae (anteromedial seta normally shortest, posteromedial and lateral setae equal, sometime all setae about equal), 1 microtubular duct, 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 lateral) in transverse rows from head to segment VII; enlarged setae of 2 sizes: larger size present along body margin, with 1 on margin of each abdominal segment, more numerous on head and thorax; smaller size in medial and mediolateral areas; largest enlarged setae 15–18 μm long; largest small-sized setae 5–6 μm; longest lateral seta 3–4 times longer than longest medial seta; lateral setae straight or slightly curved, conical, with acute to slightly rounded apices; medial setae straight, cylindrical, with blunt or rounded apices, cylindrical setae increasing in size anteriorly; setal rings thin; segment IV with 6 setae. Macrotubular ducts absent. Microtubular ducts with area farthest from dermal orifice sclerotized and divided into 2 parts, apical portion rounded and about ½ length of remaining sclerotized portion; total sclerotized area longer than unsclerotized area; dermal orifice unsclerotized. Microtubular ducts on abdomen associated with mediolateral pairs of enlarged setae, forming 1 pair of longitudinal lines; on thorax and head, microtubular ducts associated with medial or mediolateral and lateral pairs of enlarged setae, forming 2 pairs of longitudinal lines. Multilocular and cruciform pores absent. Microtrichia present on segments II to VII. With numerous nodules on medial areas of thorax and head.

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

Venter with longest flagellate seta on segment II 7–9 μm long, on segment VII 22–30 μm; longest anal-lobe seta 144–160 μm long. Enlarged setae on lateral margins from head to segment VII, ranging from conical anteriorly to cylindrical posteriorly. Macrotubular ducts absent. Microtubular ducts absent. Multilocular pores of 3 or 4 kinds: 5-locular pores and 4-locular pores normally present near spiracles; 7-locular pores usually absent, sometimes on thorax; 3-locular pores most numerous, present elsewhere; with 1 pore on each side of head, 1 near medial areas of mid- and hind coxae, and 1 pore on each side of any or all of segments II to VII, forming 1 pair of mediolateral longitudinal lines. Cruciform pores absent. Legs with each tibia with 5 setae, 1 seta in middle; each femur with 4 setae including 1 proximal seta; hind tibia/tarsus 0.7–0.8. Antennae each 6-segmented, 128–135 μm long. Frontal lobes absent. Preantennal pore present. Microtrichia in medial areas of metathorax to segment VIII, absent from coxae.

Notes: The description is based on 131 specimens from four localities. The first-instar nymph of Ac. coccineus is most similar to the first-instar nymph of Ac. arenosus by the dorsal medial and mediolateral enlarged setae noticeably smaller than the lateral enlarged setae, the predominant multilocular pores with 3 loculi, and the ventrolateral enlarged setae increasing in size anteriorly. The species differ as follows (character states in brackets are of Ac. coccineus ): dorsomedial and mediolateral enlarged setae conical (predominantly cylindrical); each femur with five setae (each femur with four setae).

Figures

FIGURE 4. Acanthococcus coccineus (Cockerell 1894), first-instar nymph, The Bronx, Bronx County, New York, USA, August 31, 1944, on Mammillaria sp. and Harrisia sp., G. Rau. A=enlarged seta; C=7-locular pore; E=3-locular pore; F=microtubular duct; H=cruciform pore; J=antenna; L=claw; N=flagellate seta.