Pedicellicoccus marginatus, Vea & Grimaldi, 2015

Vea, Isabelle M. & Grimaldi, David A., 2015, Diverse new scale insects (Hemiptera: Coccoidea) in amber from the Cretaceous and Eocene with a phylogenetic framework for fossil Coccoidea, American Museum Novitates 2015 (3823), pp. 1-80 : 47-51

Pedicellicoccus marginatus , new species

Figures 15B–C , 17

TYPE LOCALITY: Myanmar: Kachin: near Tanai Village . Albian-Cenomanian boundary .

TYPE: Holotype AMNH Bu-458 alate male; Myanmar, Kachin, Tanai Village, on Ledo Road, 105 km NW Myitkyna), Leeward Capitol Corp coll., deposited in the American Museum of Natural History.

ETYMOLOGY: The epithet is from the Latin marginatus , meaning “marginated,” and refers to the flat apical margin of the wing.

DIAGNOSIS: As for genus.

DESCRIPTION: Body minute, total length 520 μm, largest width at mesothorax, 165 μm. Head (fig. 17A): Subrotund, 135 μm wide. Ocular sclerites well developed, each with at least 5 pairs of simple eyes (probably 6, but most dorsal eyes not visible because of specimen orientation). Ocelli not observed on specimen but probably present. Antenna (fig. 17A): 9-segmented, each with an extremely enlarged pedicel; total length 195–200 μm; lengths of segments (in μm) scape ca. 20; pedicel 55–60 long, with reticulations and numerous short spinose setae; segments III to IX ca. 20, with hairlike setae. Apical segment slightly narrower, with 4 capitate setae and 2 large, curved bristles. Thorax: Head and thorax separated by a slight neck constriction. Prothorax membranous. Ridges on prothorax not visible. Mesothorax dorsally: prescutum suboval, scutum hidden by wings, scutellum suboval (rounded anterior margin) with an apparent median ridge (fig. 17B), ca. 40 μm long, 50 μm wide; mesopostnotum slightly longer than scutellum. Ventrally: basisternum 55 μm

long, 100 μm wide, with a basisternal median ridge; setae not observed. Wings (fig. 17C): Forewings very broad and rounded distally, base narrow, apical margin almost flat; ca. 500 μm long, 280 μm at widest section; subcostal ridge extending from base to more than 3/4 wing length. Cubital ridge present, point of origin unclear. Alar setae and sensoria absent, minute microtrichia present throughout wing surface. Alar lobe present. Hamulohalteres present, hamuli not detected. Legs (fig. 17D): Small, of subequal length, cuticular reticulations absent; prothoracic legs: coxa not visible; trochanter and femur, ca. 90 μm long, ca.18 μm wide, with hairlike setae; tibia: 80 μm long, 20 μm wide, setae not visible; tarsus 1-segmented, 40 μm long, 10 μm wide, setae not visible; claw small, digitules and denticles not observable. Abdomen: Elongate and narrow, almost parallel sided, tapering slightly distally (ca. 80 μm widest), 240 μm long (without genital segment ca. 195 μm). Segmentation easy to delineate. Abdominal pores not visible, pleural abdominal setae present, with a pair of longer setae on segment VIII, glandular pouches not detected. Genital segment (fig. 17E): Penial sheath triangular, of Pityococcus type (45 μm long, 22 μm wide at base), bifurcated apically. Aedeagus about same length as penial sheath. Eversible endophallus present.

Family Pseudococcidae Westwood, 1840

Williamsicoccus , new genus

TYPE SPECIES: Williamsicoccus megalops , n. sp., by present designation and monotypy.

OCCURRENCE: Lebanon, Central Lebanon, Hammana. Early Cretaceous.

ETYMOLOGY: The genus name is in tribute to Douglas Williams, for his tremendous contributions in scale insect systematics. Gender: masculine.

DIAGNOSIS: Body minute, head constriction weak, not distinctively separated from prothorax, each ocular sclerite with a dorsal and a ventral simple eye; ventral eyes meeting medially and larger than dorsal eyes; antennae with setae longer than segment width; basisternum with a median ridge; forewings elongate and thin with microtrichia; hamulohalteres long and thin, with one long hamulus; legs slender, each with one tibial spur; tarsus 2-segmented, tarsal digitule thinly clavate; claw digitules and denticles absent; abdominal segments VII and VIII with wax filaments, indicative of glandular pouches; penial sheath short.

SPECIES INCLUDED: W. megalops , n. sp.

COMMENTS: Williamsicoccus is a neococcoid genus (it possesses two pairs of simple eyes) and was classified here within the family Pseudococcidae because of the presence of wax filaments extending from the lateral sides of abdominal segments VII and VIII, indicative of the presence of glandular pouches. Glandular pouches on both abdominal segments are found in the Phenacoccinae ( Pseudococcidae ), such as in Ceroputo ( Afifi, 1968) and Phenacoccus . However, the wing shape and relative size of the ventral and dorsal eyes of Williamsicoccus differ from Ceroputo ; Williamsicoccus has a very narrow wing and has very large ventral eyes. Williamsicoccus also differs from Gilderius , n. gen., described as new below, by the latter having the dorsal and ventral eyes subequal in size and not meeting medially; the wing is particularly narrow in Williamsicoccus but round in Gilderius ; the penial sheath is longer and the antennal setae are short in Gilderius . The phylogenetic analysis failed to retrieve Williamsicoccus as included within or related to the family Pseudococcidae (as well as any relationship with Ceroputo , which was sampled in the analysis). However, our analysis found Gilderius and Williamsicoccus to be sister genera, together a sister group to Antonina , a Pseudococcidae genus. This clade was found related to Recent families including Diaspididae , Cerococcidae , Aclerdidae , and Kerriidae . This is probably due to the large amount of missing data for this taxon, so further character coding is required to resolve the relationships of this genus. For now, we consider Williamsicoccus in the family Pseudococcidae , and as such it is the oldest known fossil mealybug. (See Discussion section for Pennygullania .)

Figures

FIGURE 15. Photomicrographs of (A) lateral view of Magnilens glaesaria, n. sp., holotype AMNH Bu-1418. (B) Dorsal and (C) ventral views of Pedicellicoccus marginatus, n. sp., holotype AMNH Bu-458.

FIGURE 17. Details of Pedicellicoccus marginatus, n. sp. (A) Ventral view of head. (B) Dorsal view of mesothorax. (C) Wing. (D) Foreleg. (E) Posterior abdominal and genital segments.