Xanthonia querci Weisman, 2019

Riley, Edward G., Weisman, Donald M. & Quinn, Michael A., 2019, A taxonomic review of the Xanthonia species occurring in Texas (Coleoptera: Chrysomelidae, Eumolpinae), Zootaxa 4668 (1), pp. 1-29 : 18-20

11. Xanthonia querci Weisman , n. sp.

( Figs 7 , 53–54 , 77 ; Map 5 )

Holotype. Here designated, ♂ ( Fig 77 ) labeled || Dallas TX | IV.14.07 || FCBishop | Collector || on Quercus | sp. || NM || 206 || [glycerine-filled microvial containing male genitalia] || [red label] HOLOTYPE | Xanthonia | querci | Weisman ||. This specimen is dissected with the abdomen glued on the point and the male genitalia contained in a glycerine-filled microvial, with part of one antenna, one entire hind leg, and part of one hind tibia missing. Deposited in USNM.

Paratypes. (8 total), TEXAS: same data as holotype [5 USNM] ; same locality, IV-20-1907, F.C. Pratt [1 USNM] ; same locality, IV-25-1907, Schwarz & Pratt [1 USNM] ; same locality, IV-13-1910, W. D. Pierce [1 USNM] .

Diagnosis. Size small to medium, length 2.5–2.8 mm; dorsal ground color light to medium reddish brown with pattern of darker maculae ( Figs 7 , 77 ), venter of body dark brown to black; pubescence of elytra composed of reclined hairs on intervals in singles rows and appressed hairs arising from punctures shorter than erect hairs; ventral tooth of profemur minute; lateral margins of all ventrites entire; median lobe of male genitalia gradually tapered distally, apex rounded with short v-shaped incision and short blunt lobe on each side ( Figs 53–54 )

Description. Color: Head reddish brown, labrum and antennae yellowish brown. Pronotum reddish brown with disc transversely blackish. Elytra light to medium reddish brown with dark common median spot, each with dark spot at middle of base, one on humerus, one on middle and one on lateral area of disc, one near suture, and one on lateral area at apical third; the discal and subapical spots occasionally tending to unite both transversely and longitudinally or pattern often lighter in color, indistinct to sometimes absent ( Figs 7 , 77 ). Venter darker brownish to black with apex of abdomen lighter. Legs yellowish brown, knees often darker. Form: Length 2.5–2.8 mm. Head densely and coarsely punctate throughout and with short yellow closely appressed pubescence, face with median line faintly impressed, interantennal area slightly concave. Pronotum densely and coarsely punctate with short golden recumbent pubescence, width averaging 1.20 times length, widest at middle; sides evenly broadly rounded in dorsal aspect; anterior transverse depression moderately deep to shallow and lateral impressions obscure. Elytra length averaging 1.40 times their combined width, 2.45 times length of pronotum; basal callosity evident; punctures almost completely confused over disc and base, tending to form rows at suture and along lateral margins, often with one or two weak longitudinal costae evident on disc; punctures as large as spaces between punctures; intervals at lateral margins and at apex slightly elevated; pubescence composed of erect hairs on intervals tending to be in single lines and appressed hairs arising from punctures shorter than erect hairs. Metasternum with moderately coarse punctures near lateral edges. Abdomen with ridge on lateral margins of all ventrites entire, last ventrite of male flat without tubercles. Ventral tooth on all femora very small to obsolete. Median lobe of male genitalia in en-face view gradually tapered distally, apex rounded with short v-shaped incision that defines a short blunt lobe on each side ( Figs 53–54 ).

Range. Confined to Texas, primarily central Texas from Val Verde County north to Dallas County. Most collections are from the Edwards Plateau ( Map 5 ).

Plant associations. Weisman (1960) cited “on Quercus sp.” from label data. This species was not taken during the Travis County study; however, it was collected by beating Q. fusiformis Small in Crockett, Kinney, and Val Verde counties. Seasonal distribution. Known collections are from March through May.

Remarks. As with the preceding species, this species can be tricky to identify without reference to the male genitalia. The pattern of dark maculation, when well developed, can be helpful, and the dark “knees” of the legs are unique, but this attribute is often variably expressed and is absent from some light-colored individuals. The alignment of elytral disc punctures is variable with some individuals displaying fairly regular rows.

Specimens examined. See Appendix 9. The male genitalia of 38 males from 10 localities were examined.

Figures

FIGURES 1–9. Xanthonia species, dorsal habitus. 1) X. angulata (Bastrop Co., Texas); 2) X. dentata (Jeff Davis Co., Texas); 3) X. furcata (Wood Co., Texas); 4) X. nitida (Pecos Co., Texas); 5) X. parva (Kerr Co., Texas); 6) X. picturata (Robertson Co., Texas); 7) X. querci (Val Verde Co., Texas); 8) X. texana (Bandera Co., Texas); 9) X. villosula (Bossier Parish, Louisiana). Images to scale, scale bar = 1 mm.

FIGURES 27–54. Xanthonia species, en-face and lateral view of median lobe. 27) X. vagans (Palmerlee, Arizona); 28–29) X. vagans (Chisos Mts., Texas); 30–31) X. marquai (Jeff Davis Co., Texas); 32–33) X. picturata (Gonzales, Texas); 34–35) X. parva (Kerr Co., Texas); 36) X. villosula (Miller, Indiana); 37) X. villosula (Dallas, Texas); 38–39) X. villosula (Natchez, Mississippi); 40) X. dentata (Socorro Co., New Mexico); 41) X. dentata (Sapello, New Mexico); 42) X. dentata (Chisos Mts., Texas); 43–44) X. dentata (Cloudcroft, New Mexico); 45–46) X. hirsuta (Dallas, Texas); 47–49) X. texana (Victoria, Texas); 50) X. nitida (San Antonio, Texas); 51–52) X. nitida (Dallas, Texas); 53–54) X. querci (Dallas, Texas). All figures from Weisman (1960), except 30–31 and 32–33.

FIGURES 76–78. Xanthonia species, types and type labels. 76) X. texana; 77) X. querci; 78) X. furcata. Map 7. Distribution of Xanthonia texana.

MAPS 1–6. Distribution of Xanthonia species. 1) X. vagans; 2) X. furcata (■), X. marquai (♦), X. nitida (●); 3) X. hirsuta; 4) X. picturata; 5) X. angulata (♦), X. dentata (●), X. querci (■); 6) X. parva (■), X. villosula (●).