Gracilivectura mojavensis Mayor and 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 : 51-52

Gracilivectura mojavensis Mayor and Gimmel , new species zoobank.org/ urn:lsid:zoobank.org:act:ECBA3A7C-E162-42B7-8897-67EBED55FD3C ( Figs. 44–46 , 54 , 60–64 , 68 , 69 )

Diagnosis. Males of this species are easily distinguished from those of the only known congener, G. pygidialis , by the shape of the pygidium, which is broadly truncate ( Fig. 60 ) and the metatibia, which is parallel-sided in the apical half ( Fig. 45 ). Both males and females may be distinguished by the dense, pale setae mostly obscuring the color of the cuticle dorsally ( Figs. 44, 45 ).

Types. Holotype ♂, deposited in CAS (holotype # CASTYPE 21604), labeled “ USA: CA: San Bern Co. \ Norris Camp : Granite Mts. \ 34 48′31′′N 115 37′41′′W \ 26 April 2015 J. Hepler \ 1200m J15- 039” . Paratypes, three specimens listed in “Type Specimens Examined” section, with the additional label “ PARATYPE \ Gracilivectura \ mojavensis \ Mayor & Gimmel [yellow printed label]” .

The holotype has the terminalia dissected and mounted on a transparent card in DMHF (dimeth- ylhydantoin formaldehyde) below the specimen; the abdominal ventrites are glued to the point to the right of the specimen. The female paratype is missing the tarsomeres from the left middle leg, and the tarsomeres from both hind legs.

Description. Length: male 1.88 mm (1.79–1.94 mm, n = 3); female 2.28 mm (n = 1); width: male 0.79 mm (0.74–0.87 mm, n = 3), female 1.01 mm (n = 1). Color of cuticle predominantly light to dark brown, except prothorax (sometimes), clypeolabral region, antennomeres 1–5, basal palpomeres, epipleura, and ill-defined lateroapical crescent of elytra pale ( Figs. 44–46 ); legs generally pale, with tarsi and sometimes femora dorsally and tibiae vaguely infuscate ( Fig. 45 ). Setation pale, whitish, uniform, conspicuous, decumbent, moderately dense, mostly obscuring cuticle color ( Figs. 44, 45 ). Head: Head ( Figs. 46 , 54 ) short, broad, slightly narrower to slightly wider than pronotum in both sexes; head 1.53 (1.49–1.56, n = 3) times wider than interocular distance in male, 1.41 times wider in female (n = 1); eyes bulging, coarsely faceted. Thorax: Pronotum ( Fig. 54 ) slightly wider than long, 0.89 (0.87–0.92, n = 4) times as long as wide; widest at middle, lateral edges sinuate. Elytron 3.51 (3.34–3.74, n = 4) times as long as wide ( Fig. 44 ). Legs: Tibiae unmodified, essentially parallel sided in both sexes ( Fig. 45 ); male protarsomere 1 lobe curved, terminating in three blunt spines; male mesotarsomere 1 with a less conspicuous, curved lobe terminating in three blunt spines; male metatarsomere 1 with lobe extending to near middle of tarsomere 2, and terminating in two or three blunt spines. Abdomen: Male pygidium ( Fig. 60 ) truncate. Male sternite VIII ( Fig. 61 ) apex with deep, U-shaped medial emargination subtended by a pair of narrowly rounded lobes; with apical setae longest and densest on lobes, becoming short and sparse in emargination. Spiculum gastrale ( Fig. 62 ) with anterior strut shorter than lateral arms.Aedeagus ( Figs. 63, 64 ) parallel-sided in apical third, then sides abruptly converging at extreme apex; tegmen without median endocarina. Female terminalia unstudied.

Type Specimens Examined. Records reported here are based on the examination of four specimens. USA: CALIFORNIA: San Bernardino County: Granite Mountains, Sc 17T8NR13E [= 34.780, −115.636], 4,050′, 22–25 May 1983, T. L. Griswold (paratypes, 1♂, 1♀, UCRC; 1♂, SBMNH); Granite Mountains , Norris Camp, 34°48′31′′N, 115°37′41′′W, 1,200 m, 26 April 2015, J. Hepler, J15-039 (holotype ♂, CAS) .

Etymology. The specific epithet is an adjective referring to the Mojave Desert, where all known specimens of G. mojavensis have been collected.

Host Plant Associations. Unknown.

Geographic Distribution. Known only from the Granite Mountains in San Bernardino County, California ( Fig. 68 ).

Seasonal Distribution. 26 April to 22/25 May ( Fig. 69 ).

Remarks. Gracilivectura mojavensis is easily distinguished from G. pygidialis by the dense setae mostly obscuring cuticle color (less dense and not obscuring cuticle color in G. pygidialis ) and by the unmodified male pygidium (pygidium broadly, deeply excavated apically in males of G. pygidialis ).

The hindgut of the dissected male holotype was packed with bright yellow pollen.

Figures

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

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.

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.