Lytta (Poreospasta) cochimi Pinto, 2022

Pinto, John D. & Clark, William H., 2022, New Records of Meloidae (Coleoptera) from the Baja California Peninsula, with Description of a New Species of Lytta Fabricius, The Coleopterists Bulletin 76 (1), pp. 45-53 : 49-51

Lytta (Poreospasta) cochimi Pinto , new species zoobank.org/ urn:lsid:zoobank.org:act:8D7DAC71-C96D-4D6A-B6E6-E4F9E23DEB7C ( Figs. 1, 2 , 5–11 )

Description. Black except with a large orange frontal macula at center of head capsule; macula occupying ca. 0.4 greatest head width. Surface dull to slightly lustrous; head smooth (♀) to slightly corrugate (♂); pronotum slightly corrugate with subtle, largely transverse wrinkles at central area of disc; elytra rugulose. Head distinctly to obsolescently punctate; pronotum sparsely, obsolescently punctate. Venter, legs, underside of head, and mouthparts with moderately long black pubescence; pronotum subglabrous; elytra with short, black pubescence confined to lateral and apical margins. Fully winged; elytra complete. Length 9 (♂)– 12 mm (both ♀♀). Head: Subquadrate, 0.72 as long as wide in ♂, 0.69 and 0.75 as long as wide in ♀♀, slightly wider at tempora than below; eyes small, suboval.Antennae relatively short, subclavate, length ca. 1.5× (♀)– 2.0× (♂) pronotal width; more robust in female; length/width of antennomeres in male (holotype): 16/10, 7/9, 19/10, 13/10, 14/11, 18/12, 19/13, 17/13, 14/14, 14/13, 24/13; length/width of antennomeres in female (allotype): 17/11, 7/8, 20/10, 10/10, 10/11, 10/11, 11/12, 13/13, 14/14, 14/14, 28/15. ThoraX: Pronotum widest at apical third, 0.90 as long as wide in ♂, 0.84 and 0.89 as long as wide in ♀♀, ca. 0.8– 0.9× width of head, with sides broadly, evenly arcuate, disc surface slightly convex.Legs unmodified; not noticeably different in male and female except male with poorly developed pad at apex of protarsomeres I–IV, pads absent in female; all legs with two apical tibial spurs, those on pro- and mesotibia spiniform; hind tibia with outer spur enlarged apically, ca. 3.0× as wide as inner spur; tarsal claws moderately curved, cleft to base, blades subequal in length. Abdomen: Male ventrite 6 triangularly emarginate apically, emargination extending ca. 0.4 into ventrite; female ventrite 6 not emarginate, truncate apically. Male genitalia with gonostyli glabrous, each gonostylus bearing a mesal hook apically; aedeagus with two dorsal hooks, basal hook slightly larger, ventral hook large, robust.

Type Specimens. Holotype ♂: Mexico: Baja California: “km 115, S El Rosario”; iv-7-1979; A. V. Evans. Richard L. Westcott has collected at the km 115 site and reported (in litt.) the coordinates as 29.98732°, −115.21011° (0.85 mi. NW El Progresso). Allotype ♀ and one paratype ♀, same data as holotype. Holotype and allotype deposited in the California Academy of Sciences, San Francisco, CA ( CAS); paratype deposited in the Entomological Research Museum, University of California, Riverside, CA ( UCRC).

Etymology. After Cochimí, the name of the indigenous people inhabiting the region where the new species was collected.

Remarks. A combination of characters in the male places L. cochimi in the Stygica Group of the subgenus Poreospasta Horn as defined by Selander (1960). This includes the presence of mesal hooks on the gonostyli (the apical section of the gonoforceps, Fig. 7 ), unmodified legs, and subclavate, not incrassate, antennae ( Figs. 5, 6 ). The Stygica Group, with 12 previously described species, is primarily distributed in cismontane California with only L. stygica and L. auriculata occurring more broadly. In Selander’s (1960) keys (general key and key to Stygica Group species), L. cochimi runs to L. stygica .

Lytta cochimi is separated from L. stygica by several characters. The orange macula on the head capsule is considerably larger in L. cochimi , occupying almost half the head width ( Fig. 2 ); in L. stygica it is comprised of a small oval spot ( Fig. 4 ). The antennae are subclavate in L. cochimi ( Figs. 5, 6 ) and the antennomeres are relatively short with antennomeres IV–X about as wide as long in females. The antennae of L. stygica are subfiliform and antennomeres IV–X are clearly longer than wide in both sexes. The hind tibial spurs provide another distinction. In L. cochimi the outer spur is very broad, ca. 3× the width of the inner spur ( Fig. 11 ); in L. stygica the outer spur is, at most, twice the width of the inner spur ( Fig. 12 ). The rather deeply incised apex of ventrite 6 in the male of L. cochimi ( Fig. 10 ) contrasts with the considerably shallower emargination in L. stygica . The two dorsal hooks of the aedeagus also should separate L. cochimi ( Fig. 9 ) from most L. stygica males which, according to Selander (1960), only rarely bear a weak second hook [in Selander (1960) the dorsal hooks are referred to as ventral].

The similarity of L. cochimi and L. stygica does not imply close relationship. Their similarity rests on the fact that both lack distinctive features of other members of the Stygica Group. Distinguishing features of L. cochimi that are shared with other members of the group include the enlarged orange macula on the head and the considerably enlarged outer hind tibial spur, also occurring in Lytta sublaevis (Horn) (cf. Figs. 2, 3 ) and the two dorsal hooks on the aedeagus found also in Lytta crotchi (Horn) and Lytta hoppingi (LeConte) . Features shared by L. cochimi and L. sublaevis are likely derived but questionably homologous. Phenetically, the two species are quite distinct. Lytta sublaevis , a central California species, is unique for Lytta in being wingless with abbreviated elytra, appearing superficially similar to species of the genus Meloe Linnaeus. Also , the male genitalia and antennal structure further distinguish the two.

Figures

Figs. 1–4. 1) Lytta cochimi, new species, holotype ♂ habitus (body length = 9 mm; pin near base of right elytron removed with Adobe Photoshop®). Lytta species, head: 2) L. cochimi, new species (♀); 3) L. sublaevis; 4) L. stygica.

Figs. 5–12. Lytta cochimi, new species: 5) Antenna ♂; 6) Antenna ♀; 7–9) ♂ genitalia (length = ca. 1.5 mm): 7) Gonoforceps, dorsal; 8) Gonoforceps, lateral; 9) Aedeagus, lateral (dorsal on left); 10) ♂ ventrite 6; 11) Hind tibial spurs (outer spur on left). 12) L. stygica, hind tibial spurs (outer spur on left).