Acaricoris robertae, Heiss, Ernst & Poinar, George O., 2012

Heiss, Ernst & Poinar, George O., 2012, The first Carventinae species in Miocene Dominican Amber (Hemiptera: Heteroptera: Aradidae), Zootaxa 3268, pp. 47-54 : 51-52

Acaricoris robertae n. sp. Heiss & Poinar

(Photo 5, 6, 8)

Holotype: Male apterous specimen in an oval piece of yellowish-brownish amber from the Dominican Republic (23x15 x 6mm); dorsal and ventral side plainly visible, legs and antennae are complete. It is designated as holotype and deposited in the collection of G.O.Poinar ( CGPC) no. HE-4-64.

Diagnosis. Small apterous taxon that seems closest to Acaricoris haitiensis Kormilev, 1968 from Haiti, the western part of the same island (Hispaniola) and of which only the single holotype is known. The new species is distinguished from the latter species by longer and thinner antenniferous lobes and different outlines of the pro-, meso-, and metanotum.

Description. Holotype male, apterous, of blackish coloration, surface finely granular and partly covered by a thin ochraceous incrustation obscuring body structures.

Head. Wider than long (35/32); clypeus ridge-like, elevated with a dorsal preapical tubercle; genae flattened, longer than clypeus, apex rounded leaving a cleft at middle; antenniferous lobes long and slender, diverging anteriorly, apices blunt; antennae 1.43x as long as width of head (50/35), segment I longest and thickest, II shortest and thinner tapering toward base, III second longest but thinner and with a distinct basal pedicel, IV fusiform with pilose apex; length of antennal segments I/II/III/IV = 15/10/14 /11; eyes globose protruding; vertex medially raised and carinate, flanked by 2(1+1) ovate depressions laterally; postocular lobes not reaching outer margin of eyes and separated by a notch, then strongly converging posteriorly to a constricted collar, the latter with ill-defined transverse carina; rostrum arising from a slit-like opening, shorter than head, rostral groove wide with carinate lateral borders.

Thorax. Pronotum. Subrectangular, nearly 4x as wide as long at middle (58/15), lateral margins slightly concave, converging anteriorly, anterolateral angles rounded, anterior margin nearly straight; posterior margin sinuate at middle for the reception of a triangular lobe protruding from pronotum across meso- and metanotum and fused mtg I+II this widening posteriorly; this lobe is not clearly separated laterally from thoracic plates and moderately elevated at midline.

Mesonotum. Wider than pronotum, lateral lobes roundish, expanded and raised, a transverse suture on both sides of median lobe separates it from metanotum.

Metanotum. Fused to mtg I+II, anterolateral margins wider than mesonotum converging anteriorly, posterolateral margin delimited by posteriorly converging suture separating fused deltg II+III; lateral lobes of disk raised, their surface granulate.

Abdomen. Tergal plate raised along midline, highest on mtg IV; lateral margins subparallel on deltg II+III, then posteriorly converging, deltg VII triangularly produced; deltg III–VII separated by distinct sutures; pygophore pyriform constricted posteriorly, ptg VIII small and rounded shorter than pygophore.

Venter. Pro-, meso-, and metasternum fused to each other and posteriorly to sternites II+III; sternites III–VII separated by transverse sutures; spiracles II+III seemingly ventral, IV–VIII lateral and visible from above.

Legs. Long and slender, femora cylindrical fused to trochanters, tibiae straight, tarsi bisegmented, claws with pulvilli.

Measurements. Length 3.95mm; width of abdomen across metanotum 1.87mm, across tergite III 1.8mm, across tergite V 1.77mm.

Etymology. It is a particular pleasure to dedicate this new species to Mrs. Roberta Poinar recognizing her strong scientific interest in biological inclusions in Amber and her publications in this field. She also first illustrated this specimen in the wonderful book “The Amber Forest” (p.65 and photo 82) ( Poinar & Poinar, 1999).

Discussion. This new species shares all characters indicated in the key to genera of American Carventinae by Usinger & Matsuda, 1959: 103–104 (e.g., rostral atrium closed, eyes not stalked, postocular lobes without a projecting tubercle, male sternite VII without a glabrous pair of tubercles) leading to Acaricoris Harris & Drake, 1944 and separating this genus from the similar genera Eretmocoris, Aglaocoris, Rhysocoris, and Kolpodaptera.

However, as three of the seven species assigned to date to Acaricoris ( Kormilev & Froeschner, 1987; Heiss 2008) were described from single specimens, mostly without illustrations and sometimes with contradictory descriptions, it is difficult to recognize these taxa. This genus needs a revision based on type material.

Therefore whereas A. robertae n.sp. is at present tentatively assigned to Acaricoris , it may represent another genus.