Gilderius eukrinops, 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 : 54-55

Gilderius eukrinops , new species

Figures 18C–D , 20

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

TYPE: Holotype AMNH Bu-1594, alate male in a 3 × 4 × 1 yellow, transparent, polished amber piece with some debris; specimen is in good condition, but tilted and bent, the wings spread but hardly visible; accessible views are the ventral and dorsal surfaces of the abdomen and dorsum of the head. 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 comes from the Greek eukrines, meaning “well separated,” referring to the ventral eyes being far apart from each other, and a noun in apposition.

DIAGNOSIS: As for genus.

DESCRIPTION: Body small but robust, 840 μm long (body bent, true length probably nearer 900 μm), widest at mesothorax (ca. 300 μm wide). Head (fig. 20A): Round, ventrally protruding, ca. 210 μm wide, ca. 170 μm long. Ocular sclerites without setae, each with a dorsal and ventral simple eye; both dorsal and ventral eyes 30 μm wide, not meeting medially; with a pair of lateral ocelli (10 μm wide). Ventral or dorsal midcranial ridge not observed. Antenna (fig. 20B): 10-segmented, total length 510–530 μm; lengths of each segment (in μm): scape 40–50; pedicel 60–73; flagellar segments III to X all filiform, subequal in length; III 60; IV 45; V 50; VI 55; VII 60; VIII 45; IX 40; X55. Hairlike setae shorter than segment width (setae ca. 20 μm long). Segment X with one short bristle and four longer flagellate setae. Thorax: Head and thorax separated by a neck constriction. Prothorax membranous, ridges not observable. Prosternal structure not visible because of orientation of specimen. Mesothorax dorsally: prealare well developed; with an oval bulging prescutum (100 μm wide, 90 μm long); scutum without a membranous area; scutellum oval, almost as wide as scutum. Setae not detected. Ventrally: basisternum well developed, without a median ridge. Wings: Forewings of neococcoid type, base narrow and rounded distally, ca. 800 μm long, 400 μm wide; subcostal ridge extending from base of wing to a little more than 3/4 wing length. Cubital ridge present, starting at wing base; alar setae and sensoria absent, microtrichia present. Alar lobe present. Hamulohalteres narrow, ca. 30 μm long; each with one hamulus. Legs (fig. 20C): Long and slender, all subequal in length and shape, cuticular reticulations absent; foreleg: coxa 50 μm long; trochanter and femur, 210 μm long, 28 μm wide, with few, short hairlike setae; tibia: 155 μm long, 22 μm wide, with short hairlike setae, becoming more numerous and spinose distally; tarsus 1-segmented, 80 μm long and 20 μm wide, tarsal digitules undifferentiated; claw narrow, 10 μm long, almost straight; digitules and denticles not identified. Abdomen: Ca. 500 μm long, 210 μm widest (length without genital segment ca. 415 μm). Tergites and sternites well developed and segmentation easy to delineate. Abdominal setae not visible except for pleural setae on posteriormost segments. Tergite VII and VIII each with a pair of long setae on each side. Genital segment (fig. 20D): Penial sheath subtriangular (130 μm long, 65 μm at base). Aedeagus slender and pointed at the apex. Eversible endophallus absent.

Family Coccidae Fallén, 1814

Rosahendersonia , new genus

TYPE SPECIES: Rosahendersonia prisca , n. sp., by present designation and monotypy.

OCCURRENCE: Myanmar: Kachin: near Tanai village. Albian-Cenomanian boundary.

ETYMOLOGY: The genus name is in tribute to the Late Rosa C. Henderson (1942–2012), who has provided major contributions to the study of the fascinating scale insect fauna of New Zealand. Gender : feminine.

DIAGNOSIS: Body minute; antennae filiform, with capitate setae on apical segment; head with ocular sclerite bearing two pairs of simple eyes, dorsal eyes located anterolaterally, ventral eyes almost meeting posteriorly; ocelli present laterally; prescutum rectangular; scutum with a square membranous area medially, scutellum rectangular; basisternum without median ridge; hamulohalteres absent; penial sheath short and wide, parallel sided and apically tapered.

SPECIES INCLUDED: R. prisca , n. sp.

COMMENTS: This new genus is a definitive member of the family Coccidae based on the following combination of characters: two pairs of simple eyes, absence of hamulohalteres, presence of a square medial membranous area on the scutum, a rectangular scutellum, and a narrow neck constriction separating the head and thorax. The morphological phylogenetic analysis retrieved Rosahendersonia as sister genus to the Coccidae . When comparing this taxon to the Recent genera of Coccidae , the following combinations of characters did not allow attribution to any extant genus where adult males are known: number of eyes, absence of basisternal median ridge, absence of hamulohalteres, and the presence of ocelli. Additionally, the penial sheath is particularly short compared to extant Coccidae . This species is the first definitive occurrence of Coccidae in the Cretaceous and thus the oldest fossil of the family.

Figures

FIGURE 18. Photomicrographs of (A) dorsal and (B) ventral surfaces of Williamsicoccus megalops, n. sp., holotype 1582. (C) Dorsal and (D) ventral surfaces of Gilderius eukrinops, n. sp., holotype AMNH Bu-1594.

FIGURE 20. Details of Gilderius eukrinops, n. sp. (A) ventral view of head, (B) antenna, (C) leg, (D) dorsal view of penial sheath.