Altovectura subcyanea ( Gorham, 1882 ) Mayor & Gimmel, 2024

Mayor, Adriean J. & Gimmel, Matthew L., 2024, Two New Genera and Three New Species of Dasytinae (Coleoptera: Melyridae) from the Southwestern United States and Mesoamerica, The Coleopterists Bulletin 78 (1), pp. 33-52 : 44-48

Altovectura subcyanea ( Gorham, 1882) , new combination

( Figs. 25 , 35–37 )

Listrus subcyaneus Gorham 1882: 125 ; Champion 1914: 113, 115.

Amecocerus subcyaneus : Pic 1937: 102 (catalog).

Diagnosis. (Based on lectotype and female paralectotype.) Length of lectotype 3.5 mm; moderately densely setose dorsally ( Fig. 35 ); male pro-, meso-, and metatibiae bowed (metatibia less so) ( Fig. 35 ); male trochanters on all legs without spines; elytral apices with rounded sutural angles in both sexes ( Fig. 35 ); male ventrite 5 less deeply emarginate, emargination broader than deep, with inner margins of lobes divergent ( Fig. 36 ); male pygidium broadly, shallowly emarginate apically ( Fig. 36 ); male sternite VIII not depigmented medially, apically with very small, semicircular emargination medially ( Fig. 36 ); spiculum gastrale Y-shaped ( Fig. 36 ); aedeagus ( Fig. 25 ) with apical lobes long, outer lobes weakly sinuate on inner margin, deeply sinuate on outer margin, not hooked at apex, basal piece of tegmen abruptly narrowed in proximal half; female pygidium shallowly emarginate medially; female ventrite 5 with small, distinct emargination lined with setae.

Types. Syntypes, Listrus subcyaneus , 4♂♂, 2♀, deposited in BMNH: lectotype ♂ ( Figs. 35–37 ) , here designated, “ Type \ H. T. [round, red-rimmed printed label] // SYN- \ TYPE [round, blue-rimmed printed label] // Type [white printed label] // Totonicapam, \ 85-10,500 ft. \ Champion. [white printed label] // ♀ ♂ [white printed label] // Listrus \ subcyanea \ Gorham [white handwritten label] // B.C.A. Col. III.2. \ Listrus \ subcyaneus, G. [white printed label] // Dimetylhydantoin- \ formaldehyd \ Water soluble [white printed label] // LECTOTYPE ♂ \ Listrus subcyaneus \ Gorham, 1882 \ des.Mayor & Gimmel [red printed label] [♂ only on card mount]”; paralectotype ♀ , “ SYN- \ TYPE [round, blue-rimmed printed label] // Totonicapam , \ 85-10,500 ft. \ Champion. [white printed label] // ♀ [white printed label] // Listrus \ subcyaneus Gorh [white handwritten label] // B.C.A. Col. III.2. \ Listrus subcyaneus , G. [white printed label]”; paralectotypes, 1♂, 1♀ , “ SYN- \ TYPE [round, blue-rimmed printed label] // Totonicapam , \ 85-10,500 ft. [white printed label] // ♀ ♂ [white printed label] // Listrus \ subcyaneus \ Ch. [white handwritten label] // B.C.A. Col. III.2. \ Listrus subcyaneus , G. [white handwritten label]”; paralectotype ♂ , SYN- \ TYPE [round, blue-rimmed printed label] // TRANSCRIPTIO \ Totonicapam, \ 85-10, \ 500 ft Champion-G. \ Listrus subcyaneus [white printed and handwritten label] // Dimetylhydantoin- \ formaldehyd \ Water soluble [white printed label]”; paralectotype ♂, “ SYN- \ TYPE [round, blue-rimmed printed label] // Totonicapam, \ 8-10,000 ft. \ Champion [white printed label] // Listrus \ subcyaneus Gorh [white handwritten label] // ♂ [white printed label] // B.C.A. Col. III.2. \ Listrus subcyaneus , G. [white printed label]”. All paralectotypes with label added “ PARALECTOTYPE \ Listrus subcyaneus \ Gorham, 1882 \ des. Mayor & Gimmel [yellow printed label]” .

Other Specimens Examined. 1♂, “Quezaltenango, \ 7000 ft. \ Champion. \ ♂ [white printed label] // Listrus subcyaneus Gorh. [white hand written label] // B.C.A. Col. III.2. \ Listrus subcyaneus , G. [white printed label]”. This Champion specimen must have been added to the series after its description, since only the locality of “Totonicapam” was included in the original description of L. subcyanea ( Gorham 1882: 125) .

Geographic Distribution. This species is known only from the highlands of the Sierra Madre in Guatemala.

Remarks. One locality in Guatemala was listed in the original description: “ GUATEMALA, Totonicapam [= Totonicapán, 14°54′, −91°22′, 10,000 ft]” (coordinates in brackets are from Selander and Vaurie 1962). Gorham (1882: 125) mentioned a total of 12 specimens, though Champion (1914: 115) later mentioned having seen eight specimens from two localities; we saw six that agreed with the type series. Champion (1914: 115) added one locality, “Quezaltenango” [14°49′,

46) Frontal. Scale bars = 1.0 mm.

−91°31′, 7,657 ft] (coordinates in brackets are from Selander and Vaurie 1962).

Gracilivectura Mayor and Gimmel , new genus zoobank.org/ urn:lsid:zoobank.org:act:8F01B370-9FAF-4154-8ED4-B7A2A0EF4809 ( Figs. 38–69 )

Type Species. Gracilivectura pygidialis Mayor and Gimmel , new species, by present designation.

Diagnosis. Eyes bulging, prominent laterally, head across eyes as wide as or nearly as wide as greatest width of pronotum ( Figs. 53, 54 ). Pronotum ( Figs. 53, 54 ) narrowest at anterior and posterior angles, which are equal in width; pronotum widest at middle, which is laterally angulate. Pronotum lacking sublateral lines ( Figs. 53, 54 ). Protibia slen- der, devoid of spines along length ( Figs. 47 ); tibial spurs absent ( Figs. 50–52 ). Male protarsomeres on all legs lobed ventrally ( Figs. 50–52 ), lobes terminating in blunt spines. Tarsal claws with ungual appendages well developed, symmetrical.Aedeagus ( Figs. 58, 59, 63, 64 ) with tegmen and median lobe apparently fused, each with an acute, symmetrical apical lobe, tegmen without apical setae.

Species Included. Gracilivectura pygidialis Mayor and Gimmel , new species and Gracilivectura mojavensis Mayor and Gimmel , new species.

Description. Body size small, graciliform ( Figs. 38, 39, 41, 42 , 44, 45 ); length 1.5–2.3 mm. Color dark to light grayish, often with reddish-yellow cuticle in places (pronotum, thoracic ventrites), legs completely reddish-yellow to mostly infuscated. Moderately shining; head, pronotum, and elytra with sparse, inconspicuous microsculpture. Setation conspicuous, pale, decumbent, moderately ( Figs. 38, 41 ) to very ( Figs. 44, 45 ) dense, setae broad and flattened; with even, recumbent fringe along pronotal and elytral lateral edges. Head: Head progna- thous; frons flat ( Figs. 40, 43 , 46 ); eyes protruding laterally, width across eyes slightly narrower than greatest width of pronotum (males of G. mojavensis and all females; Figs. 41 , 54 ) to about as wide as greatest width of pronotum (males of G. pygidialis ; Fig. 53 ), with interfacetal setae present but short and inconspicuous. Mandible with single apical tooth. Antenna ( Figs. 40, 43 ) long, consisting of 11 antennomeres, moniliform, antennomere 7 broadened, 8 small and nodiform, 9–11 broadened, forming a loose club. Thorax: Pronotum ( Figs. 41 , 53, 54 ) narrow, slightly wider than long, cylindrical and evenly convex dorsally, lacking sublateral lines, carinae, or rugosity, lateral edges sinuate, widest at midlength across angular lateral lobes, width at anterior and posterior angles approximately equal; lateral bead complete to anterior margin but inconspicuous, weakly serrulate in dorsal view from small tubercles housing setal bases; anterior angles totally absent; hind angle with small denticle anterior of basal margin, causing pronotum to appear broadly, truncately lobed basally. Hypomeron with postcoxal process short, acutely angled, narrowly rounded at apex; notosternal junction with small pit adjacent to coxal cavity. Scutellar shield quadrate, slightly transverse. Elytra ( Figs. 38, 41 , 44 ) elongate, sides straight and diverging in anterior two-thirds until widest point in apical one-third, smoothly rounded to obtuse sutural angle in each elytron, with inconspicuous apical serrulations in both sexes; elytra very weakly, transversely impressed in basal one-fourth ( Figs. 39, 42 , 45 ); humeri conspicuous; lateral elytral bead scarcely visible dorsally; epipleuron moderately broad near humerus, gradually narrowing and evident until level of abdominal ventrite 3. Mesoventrite with procoxal rests anteriorly, procoxal rests defined posteriorly by complete transverse carina, divided medially by weak longitudinal carina; mesoventral process narrow, complete to metaventrite, apex sharply acute; mesanepisterna not in contact medially, with anterior transverse carina continuous with procoxal rests on mesoventrite. Metaventrite with discrimen present, extending three-fourths distance to anterior margin of metaventrite. Legs: Femora and tibiae slender in both sexes ( Figs. 39, 42 , 45 , 47–49 ); tibial spurs absent, but fringe of apical, spinelike setae present ( Figs. 50–52 ); male tarsomere 1 ( Figs. 50–52 ) modified on all legs, each bearing a ventroapical lobe terminating in blunt, toothlike spines, female tarsomeres unmodified; ungual appendages well developed, symmetrical, as long as tarsal claws, attached along entire length of claw, rounded apically. Abdomen: With five ventrites, ventrite 5 broadly truncate (males) to evenly arcuate (females) apically and with weak medioapical depression in male; male pygidium deeply emarginate ( G. pygidialis ; Fig. 55 ) to truncate ( G. mojavensis : Fig. 60 ) apically, female pygidium unmodified ( Fig. 65 ); male sternite VIII ( Figs. 56, 61 ) lacking anterior strut, undivided but depigmented medially, apically emarginate; female sternite VIII ( Fig. 66 ) with anterior strut, undivided but depigmented medially, apically emarginate. Spiculum gastrale ( Figs. 57, 62 ) Y-shaped, slender, arms simple, anterior strut long, as long as or slightly shorter than arms. Aedeagus ( Figs. 58, 59, 63, 64 ) uninverted, a slightly bowed sheath with tegmen firmly attached to median lobe; tegmen lacking apical setae. Ovipositor ( Fig. 67 ) membranous, palpiform.

Etymology. The genus name is derived from the Latin adjective gracilis, meaning “slender”, in reference to the slender build of the adult members of this genus, and the genus name Vectura . Gender: feminine.

Relationships. Gracilivectura does not appear to have any close relatives, and there are no published phylogenetic analyses to point to relationships, although an unpublished molecular analysis shows a close relationship to Vectura (Jürgen Wierz and Martin Kaltenpoth, unpublished data). Like Altovectura , members of the genus Gracilivectura have a sheath-like, apically articulated aedeagus, and probably have a relationship with the same group of genera listed under “Relationships” of Altovectura above.

Habitats. Species of Gracilivectura are restricted to desert habitats in southern California.

Host Plant Associations. Based on label data, adults of Gracilivectura have been collected from plants in the families Ericaceae , Fabaceae , and Lamiaceae ( Table 1).

Geographic and Seasonal Distribution. Gracilivectura species appear to be restricted to southern California deserts. Gracilivectura pygidialis is known only from the Colorado Desert of southern California, and G. mojavensis is known only from the eastern Mojave Desert of southern California ( Fig. 68 ).

Adults of Gracilivectura are active from late winter through spring ( Fig. 69 ).

Remarks. This genus differs from most other putative close relatives within Dasytinae by the lack of sublateral lines on the pronotum. Undescribed species of Vectura , a genus whose described members possess sublateral lines on the pronotum, from Arizona, California, and Utah exist that are small-bodied and with a narrow pronotum lacking sublateral lines. However, in these the head mea- sured across the eyes is distinctly narrower than the greatest pronotal width, the tarsal claw ungual appendages are sometimes asymmetrical, the aedeagus has a distinctly separate tegmen and median lobe, and the peculiar sexual modifications of the male protarsomeres of Gracilivectura are lacking. From Altovectura , it may be distinguished by the more cylindrical pronotum (rounded in Altovectura ), lack of pronotal sublateral lines (sublateral lines present in at least basal half of pronotum in Altovectura ), absence of ventral modification of the male abdomen (male ventrite 5 often deeply emarginate in Altovectura ), and the single apical lobe of the aedeagus (aedeagus with two pairs of apical lobes in Altovectura ).

Figures

Figs. 23–25. Aedeagus for lectotypes of species of Altovectura, new genus, dorsal. 23) A. cupreonitens;

Figs. 29–37. Altovectura species, male lectotypes; terminalia dissections were performed by the late Karel Majer. Listrus cupreonitens: 29) Dorsal habitus; 30) Dissected terminalia; 31) Labels. L. subcupreus: 32) Dorsal habitus; 33) Dissected terminalia; 34) Labels. L. subcyaneus: 35) Dorsal habitus; 36) Dissected terminalia; 37) Labels. Scale bars = 1.0 mm.

Figs. 38–43. Gracilivectura pygidialis, new genus and species, habitus (1.5 miles E of Mountain Springs Rd., Imperial Co., CA; SBMNH). Male: 38) Dorsal (inset is dorso-posterior view showing apex of pygidium); 39) Lateral; 40) Frontal. Female: 41) Dorsal; 42) Lateral; 43) Frontal. Scale bars = 1.0 mm.

Figs. 44–46. Gracilivectura mojavensis, new genus and species, male holotype, habitus. 44) Dorsal; 45) Lateral;

Figs. 47–52. Gracilivectura pygidialis, new genus and species, anterior view of male right legs and base of tarsus (1.5 miles E of Mountain Springs Rd., Imperial Co., CA; SBMNH). 47) Front leg; 48) Middle leg; 49) Hind leg; 50) Protibial apex and base of protarsus; 51) Mesotibial apex and base of mesotarsus; 52) Metatibial apex and base of metatarsus. Scale bars for 47–49 = 0.5 mm; for 50–52 = 0.1 mm.

Figs. 53–54. Pronota of males of species of Gracilivectura, new genus, dorsal. 53) G. pygidialis, new species; 54) G. mojavensis, new species.

Figs. 55–64. Male terminalia of species of Gracilivectura, new genus. G. pygidialis, new species, holotype: 55) Pygidium; 56) Sternite VIII; 57) Spiculum gastrale; 58) Aedeagus, dorsal; 59) Aedeagus, lateral. G. mojavensis, new species, holotype: 60) Pygidium; 61) Sternite VIII; 62) Spiculum gastrale; 63) Aedeagus, dorsal; 64) Aedeagus, lateral. Scale bars = 0.2 mm.

Figs. 65–67. Gracilivectura pygidialis, new genus and species (1.5 miles E of Mountain Springs Rd., Imperial Co., CA; SBMNH), female terminalia. 65) Pygidium; 66) Sternite VIII; 67) Ovipositor. Scale bars = 0.2 mm.

Fig. 68. Map of distribution of Altovectura arizonensis, new genus and species (triangles), Gracilivectura pygidialis, new genus and species (circles), and G. mojavensis, new species (star).

Fig. 69. Seasonal distribution of Altovectura arizonensis, new genus and species, Gracilivectura pygidialis, new genus and species, and G. mojavensis, new species, based on specimens examined.