A NEW SPECIES OF ORTHAEA , A NEOTROPICAL MYODOCHINE GENUS WITH AN UNUSUAL HABITAT ( HEMIPTERA : LYGAEIDAE : RHYPAROCHROMINAE ) *

The genus Orthaea, as described by Dallas (1852), was monotypic, with O. consuta the type species, and was treated by Sthl (1874) as a subgenus of Pamera (Say, 1832). In 1914, Van Duzee argued against the use of the generic name Pamera, which Say (1832) had merely employed in a faunal list with no type or original species given, and suggested Orthaea as the valid generic name for a growing assemblage of myodochine species. In his subsequent catalogue of Hemiptera (Van Duzee, 1917) Pamera Sthl (nec Say, 1832) 1874, Plociomerus A & S 1843, Gyndes Stl 1862, and Diplonotus Stl 1872 were listed as synonyms of Orthaea, which generally persisted as the name employed for the group in question until Barber (1939) synonymized it with Pachybrachius (Hahn, 1826). Harrington’s 1980 monograph of the tribe Myodochini recognized the large, catch-all genus Pachybrachius as polyphyletic, including several genera and representing separate lineages involving three of the four male genitalic types for the tribe. In that study (Harrington, 1980), the genus Orthaea, with genitalic Type IV, was resurrected from synonymy with Pachybrachius and noted to include the type species O. consuta and one other species, Orthaea procincta (Breddin) (1901). The present paper describes a new species, Orthaea alveusincola, and provides features to distinguish it and the other two known species from each other. Details of the habitat in which the type series was collected are provided since this genus apparently occupies a niche unique for members of the tribe Myodochini. All measurements in the following description are in millimeters and the Villalobos color chart (Palmer, 1962) has been used as a standard.


Psyche
[Vol. 93  Orthaea aiveusineola Harrington, new species (Figure 1)   Description.Head, anterior pronotal lobe including collar, and scutellum sooty black.Posterior pronotal lobe, background color of clavus and corium, and majority of hemelytral membrane blackish brown; posterior pronotal lobe subtly lighter, grading toward light chestnut on humeral angles.A pair of small maculae on either side of midline on anterior half of posterior pronotal lobe, anterior one- half of corial margin of clavus, adjacent base of corium, an elongate macula midlength along claval margin of corium, lateral corial mar- gin except for apical corial angle, an elongate macula running just inside and extending less than half the length membranal margin of corium (forming a V-shape with the line-like pale lateral corial mar- gin), and a small macula on hemelytral membrane adjacent to apical corial angle pale, between tawny and buffy yellow.A small diffuse area between cream ani pale gray marking the posterior margin of the hemelytral membrane medially.Antennal segment I, distal one- fourth of segment II, distal one-half of segment III, and extreme proximal portion and distal one-fourth of segment IV dark, fuscous tinged with chestnut.Femora of all three pairs of legs pale cream basally grading to between fuscous and tawny; the extent of the dark area greatest on the forelegs, covering almost three-fourths their length.Tibiae light tawny with distal ends fuscous.Tarsi with segments I and II light tawny and segment III darker.Abdomen laterally and ventrally dark chestnut, except pygophore dark tawny.
Legs, antennae, and labium smooth; antennae with short hairs and legs and labium with sparse elongate hairs.Meso-and metatibae also with bristles along full length.Head subshining with micro- rugosity and numerous short, recumbent, anteriorly directed hairs.
Pronotum pruinose and with fine recumbent hairs.Collar of ante- rior pronotal lobe and posterior pronotal lobe prominently punctate; punctures present but smaller, sparse and very shallow on anterior lobe.Scutellum pruinose, punctate, and clothed with fine hairs.Hemelytra subshining with sparse hairs emerging from punctures.Clavus with punctation in three regular rows plus an incom- plete fourth.Corium with a regular row of punctures along claval suture and another parallel row along cubitus; other claval puncta- tion randomly distributed.Abdomen ventrally and laterally sub- shining, clothed with numerous fine recumbent hairs.Head barely declivent anteriorly; somewhat prolonged in postoc- ular region, but not constricted to form a neck.Tylus not attaining midlength on antennal segment I. Vertex flattened, slightly depressed before ocelli.Ocelli behind hind margin of eyes.Eyes rounded.
Harrington and .1.A. Slater.In American Museum of Natural His- tory, New York.
Paratypes.7, 10, Same data as holotype.In American Museum of Natural History, New York; United States National Museum of Natural History, Washington; British Museum (Natural History), London and private collections of P. D. Ashlock, B. J. Harrington, and J. A. Slater.
Variation.Female specimens lack spines on the foretibia and mesofemur.They also have the anterior pronotal lobe smaller, less rounded, and in a plane lower than that of the posterior pronotal lobes.
Etymology.This species is named O.alveusincola, "river-bed dweller", for the surprising habitat in which the type series was collected.
Diagnosis.O. alveusincola, consuta, and procincta can be dis- tinguished from each other on the basis of their hemelytral color patterns.In alveusincola the lateral corial margin is narrowly pale complete to the subapical macula, which continues the pale area inward along the membranal margin in a characteristic V-shape.In both consuta and procincta the narrow pale area along the lateral corial margin extends posteriorly only about one-half to two-thirds the corial length stopping short of the pale subapical corial macula and that macula is broad and transverse, extending medially to the membranal margin instead of running at an angle as a stripe along the membranal margin.O. consuta lacks pale markings on the cla- vus, while both alveusincola and procincta have them, and O. con- suta also lacks the distinctive pair of orange maculae on either side of midline on the anterior one-half of the posterior pronotal lobe that are present in the other two species.O. consuta and procincta have the lateral margins of the posterior pronotal lobe broadly marked with orange, contrasting with the dark background; in alveusincola these margins are not so distinctly marked and only vaguely, if at all, lighter than the background.O. procincta lacks foretibial and mesofemoral spines in the males as well as females, while alveusincola and consuta males have rows of spines in both areas.
Habitat.The type series of O. alveusincola was collected among rocks in the partially dry bed of a mountain or highland stream (approximate elevation 750 m.) in Panama.The insects were most abundant in hollows and around rocks where seeds of an overhanging tree were concentrated.They ran rapidly, often entering the edges of trapped pools of water, and flew readily when pursued, indicating full macroptery consistent with the temporary nature of the habitat.Two series of O. procincta from Peru that were exam- ined in this study each also have labels reporting collection in asso- ciation with a rapid stream at high elevations (500 m. and 1600 m.).Psyche [Vol. 93  One generally would not anticipate finding rhyparochromine Lygaeidae closely associated with a stream, since their diet of seeds would be expected to either rot or germinate on moist ground.Yet a highland stream, which can by flash flooding wash and concentrate seeds and then dry rapidly, would provide a very suitable habitat with a rich concentration of a seed resource to be exploited.Members of the genus Orthaea have apparently adapted to capital- ize on this resource, since two of the three known species have been collected in such a habitat.
Currently, known distributions for the genus include O. consuta from British Guiana and Colombia, O. procincta from Ecuador, and O. alveusincola from Panama.As Orthaea is apparently a high- land genus in an unexpected habitat and thus not commonly col- lected, it is quite likely that additional new neotropical.speciesmay be found, having evolved as montane isolates.

SUMMARY
A new species, Orthaea alveusincola, from Panama is described.Diagnostic features are presented to distinguish it and the other two species in the genus, O. consuta Dallas and O. procineta  (Breddin).
The type locality is described and the unusual river-bed habitat of the genus is discussed.A full dorsal view illustration of the holotype of O. alveusincola is provided.