Xanthonia vagans (LeConte)

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 : 4-6

1. Xanthonia vagans (LeConte)

( Figs 10 , 13, 21, 27–29; Map 1 )

Trichotheca vagans LeConte 1884:12 .

Xanthonia vagans: Horn 1892:19 . Clavareau 1914: 75. Leng 1920: 292. Riley et al. 2003: 152.

Holotype. Not examined, sex undetermined (Fig 13), conserved in MCZ (images at MCZ type database viewed November, 2017). This species was originally based on one specimen collected by Gustaf Belfrage in Texas ( LeConte 1884). Weisman (1960) based his interpretation of this species on a specimen from Texas in the United States National Museum that had been compared to LeConte’s type by Doris Blake. This USNM specimen is so labeled and was examined during the present study.

Diagnosis. Size large, length 3.8–5.2 mm; ground color of dorsum medium to dark brownish, elytra usually with vague dark streaks enhanced by arrangement of variable light and dark colored elytral hairs ( Fig 10 ), venter dark brown; punctures of elytral disc in uniform rows; hairs on elytral intervals roughly in paired rows, curved and strongly reclined, shorter hairs arising from punctures very small confined to punctures (difficult to see); ventral tooth of profemur large ( Fig 21 ); lateral margins of all ventrites entire; median lobe of male genitalia long and nar- row, evenly tapered to non-incised apex ( Figs 27–28 ).

Range. Central Texas to Arizona and Sonora, México. Weisman (1960) recorded X. vagans from the Chisos Mountains of Texas, but it occurs as far eastward as the eastern edge of the Edwards Plateau ( Map 1 ). LeConte’s original type probably came from the vicinity of Bosque County where Gustaf Belfrage lived from 1868 to 1882 ( Geiser 1948). Since there are very few Arizona and New Mexico records published for this species, label data from those states are cited in Appendix 1 and that for what is apparently the first record for México (Sonora). The Utah record reported by Horn (1892) has not been verified.

Plant associations. Weisman (1960) listed “walnut” as a plant association for specimen(s) from Santa Rita Mts., Arizona. Our specimens from Travis County were taken on Juniperus ashei J. Buchholz as were some additional specimens from other counties indicating that this species is likely a juniper specialist. Label data indicate this species frequently comes to light.

Seasonal distribution. Collection dates indicate it is active later in the season. Only three specimens were taken during the Travis County study, all during late July.

Remarks. This and the following species are the most distinctive of North American Xanthonia because of their large size, greatly enlarged tooth of the anterior femur, clavate anterior tibiae, and the unique shape of the median lobe which is pointed and not incised at the apex. These characters are shared with certain other large species of Xanthonia found in México and Central America.

Specimens examined. See Appendix 1. The genitalia of eight males from six localities were examined.

Figures

FIGURES 10–12. Xanthonia species, dorsal habitus. 10) X. vagans (Cochise Co., Arizona); 11) X. marquai (Jeff Davis Co., Texas); 12) X. hirsuta (Travis Co., Texas). Scale bars = 1 mm. Figs 13–16. Xanthonia species, types and type labels. 13) X. vagans (courtesy of the MCZ type database); 14) X. marquai; 15) X. picturata; 16) X. villosula.

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 (●).

FIGURES 17–26. Xanthonia species, margins of ventrites III–V. 17) X. dentata; 18) X. parva; 19) X. villosula; 20) X. angulata. Figs. 21–22. Xanthonia species, profemora. 21) X. vagans; 22) X. marquai; 23) X. picturata; 24) X. hirsuta; 25) X. texana; 26) X. parva.

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.