Phaeocoris Jakovlev, 1887

Gapon, D. A. & Baena, M., 2005, On the status, synonymy and tribal position of Phaeocoris Jakovlev, 1887 (Heteroptera: Pentatomidae), Zoosystematica Rossica (China) 14 (1), pp. 61-68 : 62-67

Genus Phaeocoris Jakovlev, 1887 , gen. dist.

Phaeocoris Jakovlev, 1887: 306 . Type species by monotypy: Phaeocoris semenowi Jakovlev, 1887 (= Aelia elliptica Herrich-Schaeffer, 1840 ).

Timuria Horváth, 1903a: 402 (syn. Horváth, 1903b: 555).

Type species by monotypy: Timuria melanocera Horváth, 1903 (= Aelia elliptica Herrich-Schaeffer, 1840 ).

Tancreisca Jensen-Haarup, 1937: 169 (syn. Kiritshenko, 1952: 154). Type species by original designation: Tancreisca breddini Jensen-Haarup, 1937 (= Aelia elliptica Herrich-Schaeffer, 1840 ).

Lodosia Ahmad & Önder in Ahmad et al., 1996: 256, syn. n. Type species by original designation: Lodosia gonocoxa Ahmad & Önder, 1996 (= Aelia elliptica Herrich-Schaeffer, 1840 ).

Status and synonymy of Phaeocoris . Herrich-Schaeffer (1840) described Aelia elliptica from “Siberia”. Stål (1865) considered this type locality erroneous and placed the species in the African genus Dymantis Stål, 1861 as a junior synonym of D. planus (Fabricius, 1803) . Jakovlev (1887) described Phaeocoris for a new species Ph. semenowi from Altai; this name proved to be a junior synonym of Aelia elliptica . Phaeocoris was considered a separate genus until Kerzhner (1972) synonymized it with Dymantis Stål, 1861 on the basis of similar habitus.

Our observations show that Phaeocoris and Dymantis are not congeneric. Phaeocoris differs from Dymantis in the following external characters. The head is subtriangular in Phaeocoris , whereas it is elliptical in Dymantis . Antennal segments of Phaeocoris are thicker than those of Dymantis . The rostrum of Phaeocoris is slenderer, with segment 1 not reaching prosternum and segments 1 and 2 each shorter than segments 3 and 4 combined; in Dymantis , rostral segment 1 reaches or surpasses the fore margin of prosternum, segments 1 and 2 each are longer than segments 3 and 4 combined. Laminate edges of the head, pronotum and hemelytra are blunt in Phaeocoris and very sharp in Dymantis . The white longitudinal band on the head, pronotum and scutellum is narrower in Phaeocoris as compared to Dymantis . Fore femur of Dymantis bears a row of small, but distinct setiferous tubercles; in Phaeocoris , these tubercles are a few and hardly discernible. The posterior corners of connexival segments bear a small tooth in Dymantis , as distinct from Phaeocoris . The pygophore of Phaeocoris is without median projection as distinct from Dymantis . Even more essential differences are found in the structure of the male and female internal ectodermal genitalia (see the description below and the Table).

Lodosia , judging from the original description, does not differ from Phaeocoris , and, in our opinion, even their type species are synonymous.

Male genitalia of Phaeocoris . Paramere ( Fig. 1) with very wide basal plate and long stalk. Basal process of paramere small, pointed at apex, curved toward midline of body, bearing several short setae. Apex of paramere hypophysis bell-shaped; the edge of this bell on internal surface of paramere with a process tapering to apex. Membrane connecting the paramere to the wall of pygophore with a sclerite (lateral plate).

Apices of basal plates of phallobase short, less than half as long as theca ( Fig. 6). Dorsal edge of the phallobase bridge convex, angulate. Ventral processes of phallobase long and pointed at apex. Dorsal connectives rather long. Capitate processes with minute pedicels and narrowed dorsoventrally plates. Theca C-shaped, with almost parallel lateral edges. Apical part of theca rather long, not clearly delimited from basal part. Thecal base with paired membranous ventral swellings. Conjunctiva with paired ventrolateral lobes directed laterad ( Figs 9-10); their pointed apices bent towards each other. Apex of conjunctiva looking like a low dome. Dorsal processes absent. Medial plates of penis formed by short, adjoining longitudinal bands and wide apical processes parallel to vesica (lying in parasagittal planes of aedeagus). Vesica short, slightly extending beyond edges of apical processes.

Female genitalia of Phaeocoris ( Fig. 13). Base of gynatrial cone with paired large dilations of ring sclerites directed caudad. Ring sclerite very small. Spermatheca begins from gynatrial cone by a thin and moderately long duct. This duct transforms to very long membranous dilation not subdivided into two parts. Inside this dilation, there is a sclerotized invaginated funnel enveloping a thin duct, which, at some distance, opens in the spermathecal reservoir (bulb). Reservoir without diverticula.

Tribal position of Phaeocoris . The tribal position of the genus is a matter of controversy. Kirkaldy (1909) catalogued Phaeocoris in the broadly conceived tribe Pentatomini , but its synonym Timuria , in the tribe Sciocorini , in which it was placed by Horváth (1903). Dymantis , with which Phaeocoris was synonymized by Kerzhner (1972), belongs to Myrocheini , and Ahmad et al. (1996) placed Lodosia in Myrocheini .

Pentatominae with laminate sides of pronotum and a longitudinal furrow on mesosternum are subdivided into 3 tribes: Sciocorini , Myrocheini and Caystrini. Both characters mentioned are present in Phaeocoris . We did not find reliable external characters to separate these groups.

As shown in the Table, the structure of the male and female genitalia of Phaeocoris does not fit any of the 3 tribes. Most characters of this genus are plesiomorphic, shared with many groups of Pentatominae (position of the conjunctive at rest; shape of theca; structure of medial plates, lobes and apex of conjunctiva; absence of sclerotized plates on ventral side of conjunctiva; not divided swollen part of spermathecal duct); some characters are autapomorphic (e.g. structure of paramere). Unfortunately, our knowledge of Pentatominae genitalia is fragmentary, not sufficient for ultimate conclusions.

As temporary decision, we propose to retain Phaeocoris in Myrocheini , to which this genus is similar in external appearance. It is not improbable that Phaeocoris was among the ancestors of Myrocheini , but this cannot be confirmed currently.

Host plants. Specimens of Ph. ellipticus were collected mostly on the ground and under stones. A few specimens were collected from Poaceae , particularly Stipa . Much probably the bugs feed on fallen grains.

Species included. The genus includes two species.