Xystosomus nigripalpis Erwin 1973, new species
Creators: name: Erwin, Terry L.
Publisher: name: Zenodo
Year: 1973
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Xystosomus
Xystosomus nigripalpis

description: 3. <i>Xystosomus nigripalpis,</i> <b>new species</b> TYPE-LOCALITY.— <i>Barro</i> Colorado Island, Canal Zone, Panama. UASM, 2; USNM, <b>11.</b> <i>DESCRIPTION</i>.—Form: As in <i>X.</i> gruti except elytra slightly more convex. Easily distinguished by the piceous palpi, the nearly black integument of the dorsal surface, and the highly convex lateral intervals of the elytra. Color: Head and body nigropiceous; pronotum and elytra strongly iridescent; appendages partially infuscated; antennae and tarsi testaceous; palpi <b>except</b> apical article almost black. <i>Head: Frontal</i> furrows moderately impressed; eyes large and prominent. Pronotum (Figure 8): <i>Transverse</i> (W/ <b>L, x</b> 1.56; range, 1.47-1.65; 10 specimens); hind angles slightly obtuse, sides anterior to angles straight; side margins narrowly explanate basally, beaded anteriorly. <i>Elytra:</i> Striae 1-8 of each elytron well impressed and punctulate to apical third, shallowly impressed and nonpunctulate in area of recurrent groove, lateral four striae more deeply impressed and more coarsely punctulate than discal striae, especially near base; lateral intervals convex to at least <i>middle</i>, flattened gradually to apical third, discal <i>intervals</i> less convex, at least in apical two-thirds; side margins broadly explanate; humeral projection moderately developed, well rounded; chaetotaxy as in X. gruti; plica small, evident externally. <i>Microsculpture: As</i> in <i>X. gruti.</i> <i>Secondary sexual</i> characters: <i>Male</i> genitalia <i>characteristic</i> of the group (<i>Figure</i> 25). Female genitalia characteristic of the species group. Size: <i>Ten</i> specimens: length, 3.3-3.9 mm; width, 1.5-1.8 mm. NATURAL <i>HISTORY</i>.— <i>The</i> type series was collected in and on deep litter at the crown of a fallen tree in the humid, tropical, semideciduous forest of Barro Colorado Island, Panama. The individuals were very active in sunlight (sparse as it was in this part of the forest) and shade, commonly running over undisturbed leaves and twigs. Most specimens were found in the deep leaf litter where the leaves were wilted but not decomposed. <b>Our</b> method of raking and reraking the leaves knocked most specimens to the soil, but close observation showed the beetles to be among the leaves <i>off</i> the soil. No specimens were teneral. All of these beetles were collected alive and taken to Washington for behavior studies and breeding purposes, the results of which will be published separately. (See also <i>X</i>. <i>gruti</i> <i>,</i> under Behavior.) I have observed captive specimens in flight. <i>LOCALITY RECORDS</i> (Figure 69).—I have seen 23 specimens from the following locality: CENTRAL <i>AMERICA</i>: PANAMA: Canal Zone, Barro Colorado Island.
description: Published as part of <i>Erwin, Terry L., 1973, Studies of the subtribe Tachyina (Coleoptera: Carabidae: Bembidiini), Part I: A revision of the Neotropical genus Xystosomus Schaum, pp. 1-39 in Smithsonian Contributions to Zoology 140</i> on pages 9-10, DOI: 10.5479/si.00810282.140, http://zenodo.org/record/3828531