Subfam. Xyletininae.
Hadrotinus procerus sp. n. (Fig. 1). General view. Beetle nearly black. Pronotal anterior margin reddish. Antennae greyish-yellow. Fore and middle tibiae and tarsi light brown. Pubescence light grey, bristly, suberect. Body 2.5 times as long as wide (Fig. 1, 1). Head. Eyes round, large, convex, slightly notched against antennae, separated by about 1.2 vertical diameter of an eye. Antennae serrate; 3rd and 4th segment nearly cup-shaped, next segments strongly transverse, triangular (last segments are lost) (Fig. 1, 2). Last segment of maxillary palpus is almost triangular, with emarginate apex (Fig. 1, 3). Pronotum with full side margin, 1.4 times as wide as long; anterior angles nearly rectangular, not reflexed down to the lower side of the head, posterior angles obtuse, rounded, sides bulging above posterior angles (Fig. 1, 4). Disc with longitudinal low carina in basal half, and with slight constriction anteriorly (Fig. 1, 1). Surface with very fine, dense granulation. Elytra 1.9 times as long as wide and 2.6 times as long as pronotum; elytral ends truncate. All surface with deep striae; each stria consists of large, coarse punctures (Fig. 1, 5). On the disc the punctures merge through the row into continuous grooves. Near-sutural stria consists of small, rarefied punctures beginning from the middle of the disc to the top. Interstriae strongly convex, being as wide as the width of striae on elytral disc. Every other interstriae is convex on sides. Punctures arranged in disorder on the elytral apex. Lateral margins emarginate for hind legs. Metasternum is sloping forwards. On basal margin there is a triangular convex process in the middle for separating the middle coxae. Distal half of metasternum with longitudinal groove in the centre (Fig. 1, 6). Legs. Anterior coxae elongated, strongly projected backwards, their apices touching. Middle coxae narrowly separated by metasternal process. Tibiae with groove to put in the tarsi. Anterior tarsi are 0.6 times as long as their tibiae. First tarsimere is the longest, twice as long as the second one, the fifth tarsimere is about as long as the second one (Fig. 1, 7). Length 3.5 mm. Argentina. H. procerus differs from H. striatus White, 1973 by longer body (body 2.1–2.2 times as long as wide in H. striatus) and truncate elytral ends. The new species differs from H. wagneri (Pic, 1915) by the colour of body (H. wagneri is brick-red (Pic, 1915)) and by truncate elytral ends.
Lasioderma solarii sp. n. (Fig. 2). General view. Body elongated-oval. Beetle bicoloured; elytra yellow, pronotum and head brown. Pubescence pale-yellow, homogenous, rather long, a little suberect. Body about 1.6 times as long as wide (Fig. 2, 1). Head. Eyes round, convex, without cut or notch, separated by two vertical diameters of an eye. Antennae serrate. Pronotum 1.56 times as wide as long, with full side margin. Anterior angles are very acute, not reflexed down to the lower side of the head; posterior angles slightly expressed (Fig. 2, 2). Pubescence indistinctly parted to two sides (Fig. 2, 3). Punctation on disc is very fine, obsoletely dual (Fig. 2, 4). Elytra 1.3 times as long as wide and 2.1 times as long as pronotum. Surface without any striae. Shoulder-knobs present. Elytral side margin feebly emarginate for hind legs. Surface with fine, obsolete dual punctation (Fig. 2, 5). Legs. Hind legs are lost. Fore tibiae not dilated to apex. Tarsi are very thin (Fig. 2, 6). Abdomen. First suture is single, curved backwards; the rest sutures are duplex, straight. Length 2.05 mm. Salvador. The new species differs from widely distributed Lasioderma serricorne (Fabricius, 1792) mainly by anterior tibiae not dilated to apex; from L. gracilipes Toskina, 1993 from Paraguay by shorter body and brownish-yellow colour; from L. tucomaniense sp. n. from Argentina by short pronotum.
Lasioderma tucomaniense sp. n. (Fig. 3). General view. Beetle dark rufous. Pubescence homogenous, small, yellowish, suberect. Body 1.56 times as long as wide (Fig. 3, 1). Head. Eyes small, round, without notch, convex, separated by about 2.5 diameters of an eye. Antennae strongly serrate, middle segments transverse, with concave apical margin and very slightly convex lateral margin. Pronotum 1.4 times as wide as long. Anterior angles acute, posterior angles absent (Fig. 3, 2). Pubescence parted to two sides on apical two-third of pronotal surface (Fig. 3, 3). Pronotum evenly convex, without bulgings. Punctation small, dense on the disc (Fig. 3, 4). Scutellum triangular. Elytra 1.2 times as long as wide and 1.8 times as long as pronotum. Surface with small and dense punctures (Fig. 3, 5), which are twice as large as punctures on pronotum. Legs. Fore tibiae slightly widening to apices (Fig. 3, 6). Abdomen. 2nd–4th abdominal sternites with rare and bristling hairs along distal margins which look like denticulate. Length 2.5 mm. Argentina. The new species differs from L. serricorne (Fabricius, 1792) by pubescence pattern on pronotum, by strongly serrate antennomeres, by slightly extended fore tibiae. L. tucomaniense differs from L. gracilipes Toskina, 1993 by short body, by suberect pubescence, by colour. The new species differs from L. solarii sp. n. by shorter pronotum, by not dilated fore tibiae, by dark rufous colour.
Subfam. Dorcatominae.
Astichticus gen. n. (Fig. 4). General view. Beetles are elongated-oval (Fig. 4, 1). Elytra with two lateral striae. Pubescence appressed. Head. Eyes of medium size, convex, without notch. Antennae 11-segmented, with 3-segmented loose club; 2nd and 3rd segment oblong, 4th–8th segments transverse, uniform, 9th–11th segments oblong (Fig. 4, 2). Last segment of maxillary palp looks like a spatula with a truncated top. Pronotum slightly convex, without bulgings and gibbosity, with full side margin. Anterior angles almost rectangular. Posterior angles are distinct, rounded. Pronotal basal margin is as broad as elytra. Elytra with two lateral striae (Fig. 4, 3). Disc without striae and with rows of small punctures. Shoulders well developed. Lateral margins emarginate for hind legs. Distal margin of mesosternum and basal margin of metasternum form valleculae for middle femora. Metasternum with middle groove, which widens forward to basal margin. The middle is bulging above each hind coxa (Fig. 4, 4). Basal margin of metasternum without fungiform process or “fork”. Legs. Pro-, meso-, and metacoxae separated. Tibiae in section square. Tarsi short. Fore tarsi are 0.5 times as long as their tibiae (Fig. 4, 6). Claws short, simple. Abdominal sternites merged: sutures single and reduced in the middle. First sternite with excavations for hind legs and this sternite is the shortest; the 5th sternite is the longest. Aedeagus is of complex shape. Side processes without bundles of hairs (Fig. 4, 7). The new genus is the most related to the genus Stichtoptychus, and differs from the latter by the absence of striae on elytral disc, by bulgings on metasternum, by merged abdominal sternits, and by the form of aedeagus.
Astichticus bordoni sp. n., type species (Fig. 4). General view. Beetles black-brown. Antennae: 1st segment is very dark, 2nd segment is light, the remaining segments are dark brown; tarsi brown. Pubescence brown, appressed; hairs very short and arranged in a ring pattern. Body 1.8 times as long as wide (Fig. 4, 1). Head. Eyes round, separated by 1.5 diameters of an eye. Antennae: first segment is large, falciform, 2nd and 3rd segment oblong, 4 to 8 segments transverse, 9–11 segments oblong (Fig. 4, 2). Pronotum 1.5 times as wide as long; anterior angles a little reflexed down to the lower side of the head, posterior angles obtuse, rounded (Fig. 4, 3). Surface with small, sparse punctation. Elytra 1.3(♀)–1.4(♂) times as long as wide and 2.20(♀)–2.25(♂) times as long as pronotum. Lateral striae: the lower one reaches elytral basal margin, the upper one reaches only the level of shoulder (Fig. 4, 3). Elytral disc with rows of small, shallow, sparse punctures not forming striae. Metasternum: distal margin bulging above each hind coxa. The median groove widens forward to basal margin (Fig. 4, 4). Convex parts with clear uniform punctation in which punctures are separated by 1–1.5–2 diameters of a puncture (Fig. 4, 5). Legs. Tarsi short; first segment is the longest; 2nd, 3rd, and 4th segment short; the 5th segment is longer than the 2nd one (Fig. 4, 6). Aedeagus in Fig. 4.7. Length 2.95–3.30 mm. Venezuela.
Metapetalium klepikovae sp. n. (Fig. 5). General view. Beetles elongated, nearly cylindrical; black-brown or black; antennae and mouth palpae yellow, tibiae and tarsi brown. Pubescence fine, dark grey, not dense, a little suberect. Body 2.1*–2.3 times as long as wide (Fig. 5, 1). Head. Frons convex. Eyes round, slightly convex, without notch or cut, separated by 1.1(♂)–2.0(♀) vertical diameters of an eye. Antennae 9-segmented, with 3-segmented club (Fig. 5, 2). Last segments of maxillary palpae with deeply notched top (Fig. 5, 3). Pronotum 1.4*–1.5 times as wide as long, convex, bulging above obtuse posterior angles, without gibbosity; anterior angles acute. Anterior margin thickened and strongly suberect (Fig. 5. 4). Sides rounded when viewed from above. Surface with dense punctation on disc (Fig. 5. 5). Scutellum triangular. Elytra 1.4–1.6* times as long as wide and 2.0–2.3 times as long as pronotum. Shoulder-knobs present. Sides with two lateral striae of large punctures. Interstria strongly convex between these striae. Pubescence arranged in narrow, unclear, longitudinal strips of hairs on weakly convex places, because of what elytra look like slightly striped (Fig. 5. 1). Metasternum with short groove in the middle of distal margin. Basal margin with fungiform process; the latter with flattened apical margin (Fig. 5. 6). Abdomen. The second sternite is the longest, and the forth sternite is the shortest (Fig. 5. 7). All ventral surface is covered with very dense, homogenous punctation (Fig. 5, 8). Length 1.6*–1.75 mm. Nicaragua, Guatemala. The new species differs from African species of Metapetalium by the form of pronotum – without gibbosity.
All holotypes and paratypes are deposited in the collection of the Museo civico di storia naturale di Genova.