Carabus bipustulatus Fabricius, 1792: 161

Number of described Western Hemisphere species: 16

Stable, although several recently collected undescribed species need to be treated. Adelphotaxon: not determined.

Members of this genus occur in the Antillean sub-region of the Neotropical Region, Amazon Basin of Perú, the Holarctic Region, Afrotropical Region, in the Cape sub-region, and on the island of Madagascar (Ball 1959), Oriental Region eastward to Java, and the Australian Region, including New Guinea and eastern Australia (Darlington 1968: 15).

Wet and moist areas including shaded margins of vernal pools in deciduous forests, open margins of alkaline lakes, secondary floodplains of river banks, at eutrophic marshes, pond and lakes, in disturbed places such as gravel pits, vacant lots, pastures, and cultivated fields (e.g., barley).

(Ball (1959, 1992), Jeannel (1942), Larochelle and Larivière (2003).

(modified from Ball 1959).— With character states of subtribe Licinina (Ball 1992: 347, in key), and the following: Length not exceeding 10 mm, body glabrous, except for certain constant setae mentioned below; mandibles thick, either right or left mandible with deep transverse notch in dorsal surface, notch preceded proximally by a prominent boss; tibial spurs finely serrulate; antennomeres 3–11 densely setose.

Head (Fig. 2) with two supraorbital setigerous punctures per eye, frontal impressions usually shallow, basin-like. Clypeus (cl) markedly and slightly asymmetrically emarginate, not divided into two portions by the emargination, deflected ventrally, forming an angle of somewhat less than 90 degrees with the front, bearing a single long seta on each side, each of which originates in a broad approximately triangular pit. Eyes prominent. Antenna with complex variety of sense organs beginning on antennomere 3 (a3). Labrum (lb) about 2/3 as wide as clypeus, deeply bilobed, cleft anteriorly almost extended to base, with three setae on each lobe. Mandibles very short and obtuse, terebra markedly reduced, apparently edentate; either right or left mandible deeply notched (mn), preceded by a prominent swelling, or boss (mb). Maxillary palpi long and slender, palpomere 4 (mp4) fusiform, slightly broader than palpomeres 1–3, narrowly truncate apically. Labial palpus with palpomere 2 bisetose; palpomere 3 (lp3) securiform, distal margin obliquely truncate.

Prothorax. Pronotum (Fig. 1) wider than head, more or less cordate, a pair of setigerous punctures on each side, one of the pair at posterior lateral angle, the other just inside lateral margin about half way between base and apex; narrowly margined laterally, hind angles obtuse, slightly to markedly rounded. Proepisternum with microsculpture mesh pattern longitudinal; microlines fine, transverse on remaining lateral and ventral thoracic sclerites. Prosternum with apex of intercoxal process feebly margined, asetose.

Pterothorax. Metepisternum elongate, the outer margin about 1.5 times greater in length than the anterior margin, posterior margin about 0.75 times anterior margin.

Elytra. Oblong, wider than pronotum at widest point, apical margin entire or very slightly sinuous, interneurs fine, parascutellar interneur (Fig. 3A, pss) long, joined or not to apical portion of interneur 1; intervals flat to slightly convex with two discal punctures on interval 3, adherent to interneur 2. Lateral marginal (umbilical) series of 15–18 setae, concentrated and narrowly spaced in anterior and posterior thirds, with few widely spaced setae medially.

Hind wings. Macropterous or brachypterous. Venation not studied.

Legs. Slender; tibial spurs very finely serrulate; posterior tarsi very slender, dorsal face dull and medially feebly sulcate; anterior tarsi of male (Fig. 3B–C) with tarsomeres 1–3 markedly or slightly dilated, with extensive or limited patch of adhesive articulo-setae ventrally (Fig. 3C) (also, see Stork 1980: 195, 290, for detailed description of adhesive setae of Badister bipustutulatus (Fabricius))

Abdominal sterna. Surfaces with very fine, transverse microlines, very close together, surface quite iridescent. Abdominal sternum VII with two setigerous punctures on posterior margin in male, four in female, apical margin more rounded in the male, more truncate in the female.

Pygidial glands as in Fig. 4, showing a short efferent duct(ed), a large gland reservoir(gldr), a long narrow collecting canal (cc), and basal lobe of efferent duct (edbl).

Male genitalia (Fig. 5A-C). Median lobe moderately arched in typical subgenus, straighter in subgenus Baudia, (see Figs 134–155 in Ball 1959); basal bulb somewhat reflexed, sides not emarginate, dorsally mostly membranous, with two or three long sclerotized strips.

Ovipositor and female reproductive organs (Fig. 6A–D). Gonocoxite 2 (gc 2)falcate, base (b) about as long as blade (bl), latter relatively short, pointed distally; margins with several ensiform setae; with or without short preapical nematiform setae. Reproductive organs standard for Carabidae, with bursa copulatrix, common oviduct, spermatheca, and spermathecal glands (for details, see this topic below, in description of Badister amazonus, n. sp.).

In addition to the features presented in the generic diagnosis and description above, all of the Western Hemisphere species of the typical subgenus have the right mandible deeply notched (Fig. 2, mn), and a row of setae on each latero-ventral margin of tarsomere 5. Another useful attribute in distinguishing the subgenera is the relative length of the hind tarsi. In adults of Badister and Trimorphus, the posterior tarsi are more than 3/4 the length of the hind tibiae; in Baudia, the hind tarsi are perceptibly relatively shorter.

(Western Hemisphere).—The known range of this subgenus includes Amazonian Perú in South America, Middle American countries of Costa Rica, Honduras, Belize and México, and the North American countries of USA and Canada.

(Modified from Ball 1959)

Perú, Loreto, 1.0 km SW boca del Rio Samiria, Vigilante Post 1, 130m, “04°40.5'S, 074°18.9'W" 31 August 1991 (T.L. Erwin & M.G. Pogue)(NMNH: ADP051824, male).

The epithet “amazonus” is a singular Latinized masculine noun in apposition, based on the name of the area in which these beetles were found.

Amazon Fast-walking Beetle.

With the attributes of the subgenus Badister, as described by Ball (1959) and as noted above, and large-sized for the genus (mean SBL more than 6.1 mm for both males and females of Badister amazonus; mean SBL less than 5.9 mm for males and females of all other Western Hemisphere species samples). Adults with black head and elytra, the elytron with flavotestaceous base, sutural interneur, lateral margin, and epipleuron, and shiny throughout; prothorax and venter flavotestaceous; appendages testaceous. Microsculpture mesh pattern of head and pronotum isodiametric, surface luster somewhat dull; of elytron, very finely etched transverse lines, surface shiny iridescent. Labial palpomere 3 (Fig. 2, lp3) swollen and triangulate (distal margin obliquely truncate) with a very small pointed knob at apex. Pronotum with lateral margin moderately explanate in anterior half, broadly so posteriorly. Male tarsomeres 1–3 (Fig. 3B, 3C) slightly widened, with rows of adhesive vestiture on ventral surface narrow, confined to anterior half).

(Fig. 1, 2, 3A–C, 4, 5A–C, 6A–D, 7). Size: Moderately large for the subgenus; ABL = 6.2–7.9mm, SBL = 5.36–6.73mm, EW (maximum width) 2.55–3.43mm, LP = 0.97–1.22mm, WP = 1.71–1.91 mm, LE = 3.86–4.84mm. Color: See Diagnosis above. Luster: See Diagnosis above. Head (Fig. 2): clypeus (cl) medially depressed, unisetose laterally, no clear demarcation from frons. Frons markedly depressed, apically with depression extended to eye carina, posteriorly somewhat concave with slight swellings medially raised to occiput; occiput shallowly domed; neck broad. Eye moderately convex; gena short and flat. Antennae and mouthparts typical for genus (see above for details) .

Prothorax. Pronotum (Fig. 1, 2) markedly broad, about twice as long as head (mean LP/LH: 1.683 for males , 1.846 for females), cordiform, margin narrowly explanate with seta at anterior third; base deeply and bilaterally depressed; hind angle slightly obtusely produced and setose; moderately broader than long (mean W/L: 1.71 for males, 1.91 for females); surface medially smooth, slightly rugose laterally medial to explanation.

Pterothorax. Normal for genus.

Elytra. Elytron about same width as head across eyes (mean WH/WE: 0.998 for both sexes), moderately convex, intervals moderately convex and slightly more so laterally, interval 3 bisetose with each setigerous puncture adherent to interneur 2.

Hind wings. Macropterous.

Legs. (Fig. 1). Overall, normal for subgenus. Male front tarsus (Fig. 3B, 3C) with tarsomeres 1–3 slightly dilated and each ventrally (Fig. 3C) with 2–4 rows of white articulo-setae.

Abdominal sterna with normal setation for genus.

Male genitalia (Fig. 5A–5C). Median lobe (ml) with basal lobe (bl) about half length of shaft (sh), basal opening (bo) large. Shaft slender, curved ventrally, dorsally membranous (om) except for two long sclerotized strips (ss) extended from basal lobe to ostial opening (oo); in ventral aspect tapered toward rather broadly rounded apex, preapically with prominent preapical ridge (par), in lateral aspect, ridge a prominently projected point. Parameres (lp, rp)broad, apices subtruncate left paramere (lp) longer than right paramere (rp) about three quarters length of shaft (measured in left lateral aspect). Internal sac with apical ring of rather densely distributed microtrichia, without preapical spines.

Female genitalia. (Fig. 6A–D). Ovipositor with broad laterotergite (lt) and two gonocoxites (gc 1, gc 2); gonocoxite 1 asetose; gonocoxite 2 falcate, base (b) large, broad, blade (bl) rather short, with two dorsal ensiform setae (des), and one ventral ensiform seta (ves), all ensiform setae short; without ventral preapical nematiform setae. Reproductive tract (Fig. 6A, 6B) proximally with short, broad bursa copulatrix (bc), continuous at its distal end with common oviduct (co) and long spermatheca (sp), latter coiled distally; villous canal (vc) extended from near base of spermatheca well up common oviduct; spermathecal gland (sg) bulbous; spermathecal gland duct (sgd) long, slender, attached to spermatheca at base of its coiled portion.

Markedly similar to homologous structures in Badister (Baudia) reflexus LeConte (Will 1998: 99, Fig. 8), which differ as follows: spermatheca with basal uncoiled portion more extensive; distal coiled portion short; spermathecal gland elongate digitiform.

Classification. Ball (1959: 194–195) arranged the species of subgenus Badister in two “complexes” characterized principally by features of the male genitalia and ovipositor gonocoxite 2. The combination of these features in Badister amazonus fits neither complex. Accordingly, we propose here the monobasic amazonus complex, characterized as follows: median lobe of male genitalia dorsally with two long sclerotized strips, internal sac without sclerotized plates or spines; gonocoxite 2 of ovipositor relatively broad basally, ensiform setae relatively short; nematiform setae absent. Additional diagnostic features are: male fore tarsomeres 1–3 (Fig. 3B) relatively slender, not much wider than tarsomeres 1–3 of middle and hind tarsi, fore tarsomere 1 longer than wide, ventral adhesive setae (Fig. 3C) concentrated in anterior half of each tarsomere.

Dispersal potential. These beetles are fully macropterous and are probably capable of flight; they are fast walkers. They also are climbers on grasses (Paspalum spp.).

Way of life. Adults are associated with water: in open grassy marshes, on beaches of black and white water rivers, and in forest swamps at the edges of standing black water ponds in leaf litter on grey clay soil (Kaolin). They are active at night and take cover in the day among grass stems and under flood debris. They are active in May and August–September; no teneral adults were encountered in these months.

Other specimens examined. Perú, Loreto, SW bank of Rio Ucayali, 90m, 4.2089°S, 73.3657°W, 2 September 1991, (T.L. Erwin)(NMNH: ADP051862, female); Pacaya-Samiria National Reserve, Rio Samiria, Cocha Shinguito, 90m, 5.1775°S, 74.6556°W, 21 May 1990 (T.L. Erwin)(NMNH: ADP093676, 128618, females); 1.0 km SW boca del Rio Samiria, Vigilante Post 1, 130m, "04°40.5'S, 074°18.9'W" 31 August 1991–1 November 1991 (G.E. Ball & D. Shpeley)(NMNH: ADP127151, female, 127149, male); 1.0 km SW boca del Rio Samiria, Vigilante Post 1, 130m, "04°40.5'S, 074°18.9'W" 31 August 1991 (T.L. Erwin & M.G. Pogue)(NMNH: ADP051697, 051603, 051336, 051721, 051672, 051743, 051693, 051698, 051722, 051694, 051724, 051692, 051670, 051717, 051718, 051723, 050590, 050589, 050605, 051696, 051720 females and ADP051824, 051630, 051719, 051713, 051826, 051691, 051695 males); 1.0 km SW boca del Rio Samiria, Vigilante Post 1, 130m, "04°40.5'S, 074°18.9'W" 31 August 1991 (T.L. Erwin)(NMNH: ADP051592, 051563, 051544, 051583, 051589, 051559, 051590, 051564, 051567, 051569, 051561, 051581, 051585, 051570, 051584, 051565, 051543 females and ADP051562, 051541, 051591, 051542, 051566, 051588, 051560, 051568 males).

Two males and 12 females at UASM with the following label data: /PERU Dpto. Loreto/ 1 km SW Boca del Rio/Samiria 04°40'29"S, 74°18'55"W 130m/marsh, treading/31.VIII.& 1.IX.91 30–91//T. L. ERWIN EXP./Res. Pacaya-Samiria/G.E. Ball & D. Shpeley/collectors 1991//.

Geographic distribution. (Fig. 7). This species is currently known from only three localities: two along the Río Samiria, and one along the Río Ucayali, Loreto Department, Perú.

Notes. We are not presenting an analysis of variation in body proportions because this species can be separated from all other members of the genus without resorting to such attributes. In regard to the location (latitude/longitude) above for “1.0 km SW del boca Rio Samiria, ” Google Earth allows us now to refine what is given on the labels. The actual site is 4.686779°S, 74.336711°W at an elevation of 101m. Also, the female specimen from the Río Ucayali was mistakenly labeled “Río Amazonas.” The river changes names in the vicinity of Iquitos, Perú.