Schinia immaculata Pogue

Pogue, Michael G., 2004, A new species of Schinia Hübner from riparian habitats in the Grand Canyon (Lepidoptera: Noctuidae: Heliothinae), Zootaxa 788, pp. 1-4 : 2-4

Schinia immaculata Pogue , new species

( Figs. 1, 3–4 )

Diagnosis. Schinia immaculata resembles S. biundulata Smith in size, forewing ground color, and dark hindwing, but S. biundulata has well defined antemedial and postmedial lines, which are absent in S. immaculata . In male genitalia the shape of the valve is different, with S. immaculata having a round apex ( Fig. 3 ) versus a more pointed apex ( Fig. 5 ) in S. biundulata ; and the uncus is relatively longer, approximately 0.38 X length of the valve in S. immaculata , compared to 0.32 X length of valve in S. biundulata .

Description. Head: Frons and vertex cream; labial palpus long, extending beyond frons, cream; eyes large and globular. Thorax: Scales hair­like overlaying wide scales, cream; fore femur cream with long, white, ventral fringe of hair­like scales; tibia white, largest spine on inner side elongate, round, 1 shorter slender spine dorsal to it, outer side with 2–3 slender spines that become progressively shorter proximally; tarsi white; middle and hind legs white; underside white. Forewing: Length 10.53–11.70, mean 11.21 + 1.21 mm (n=4). Ground color cream with a faint tinge of rufous on the scales; pattern absent; fringe white. Hindwing: Ground color gray; pattern absent; base of fringe cream, rest white. Abdomen: Dorsum white, distal border of sternites cream, ventrum white; scent pockets and hair pencils on second sternite absent. Genitalia ( Figs. 3–4 ): Uncus elongate, approximately 0.38 X length of valve, apex blunt with small hook; valve moderate (length approximately 7.1 X width), costal margin slightly bent at 2/3 length, posterior margin gently curved, apex round; ampulla small (0.04 X length of valve); corona with stout spines; sacculus with ventral margin produced; juxta rectangular, width greater than height, dorsal margin broadly V­shaped; saccus V­shaped; aedoeagus slightly curved; vesica emerging ventrally, basal diverticulum present, 3 1/2 coils; cornuti finely scobinate.

Female: Unknown.

Type material. HOLOTYPE: ɗ, Arizona, Coconino Co., Colorado River, Grand Canyon, river mile 23.0 L, shore, 36.6003° N, 111.7668° W, May 2, 2003, R. J. Delph, genitalia slide USNM 47867, USNM ENT 0 0 219964. The holotype is provisionally deposited at the USNM, Washington, DC, pending mutual resolution and agreement with the National Park Service regarding specimen deposition.

Distribution and Habitat. Specimens were taken from 3 riparian zones of the Colorado River in the Grand Canyon in Coconino Co., Arizona: shoreline, old high water, and new high water. The shoreline zone is situated one meter above the existing daily highwater shoreline, which varies over time depending on water releases from Glen Canyon Dam. The new high water zone is situated just above shoreline and was characterized by vegetation dominated by tamarisk ( Tamarix sp., Tamaricaceae ). The old high water zone was the highest elevation hydrologic zone and was characterized by mesquite ( Prosopis sp., Fabaceae ), acacia (Acacia sp., Fabaceae ), and desert shrubs. A total of 34 sites were selected within these zones to monitor arthropods. This information was summarized from the Grand Canyon Arthropod Inventory & Monitoring website: http://bugs.bio.nau.edu/ grand_canyon/index.htm.

Material Examined. PARATYPES (3°): U.S.A.: ARIZONA: COCONINO CO. 1° same data as holotype except: USNM ENT 0 0 210120 ( NAU); river mile 166.5 L, old high water, 36.2542 N, 112.8996 W, 14 Apr. 2003 (1°), R. J. Delph, USNM ENT 0 0 219965 ( USNM); river mile 202 R, new high water, 36.0526 N, 113.3489 W, 15 May 2001 (1°), J. Rundall, USNM ENT 0 0 210119 ( NAU). Paratypes deposited in the National Museum of Natural History, Washington, DC ( USNM) and Northern Arizona University, Flagstaff, AZ ( NAU).

Etymology: The specific epithet, immaculata , refers to the lack of any pattern on the forewing and hindwing.

Discussion. Unlike most species of Schinia , S. immaculata has no forewing markings in all but one paratype, which has a barely perceptible trace of both an antemedial and postmedial line ( Fig. 1 ). The form of the foretibia, male genitalia, and the coils of the aedoeagus are typical of Schinia . The species was collected in all riparian zones of the study area. Schinia immaculata is a spring flyer, being active from mid­April to mid­May. Other large river systems in the southwestern United States should be investigated to try to learn more about the distribution of this unusual species.

Figures

FIGURES 1 – 6. Adults and male genitalia. 1, Schinia immaculata, male, Arizona, Coconino Co. Colorado River, Grand Canyon, river mile 166.5 L, USNMENT 00229965; 2, S biundulata, female, Nevada, Humboldt Co. Sulphur, USNMENT 00220807; 3, S. immaculata, male genitalia; 4, S. immaculata, aedoeagus; 5, S. biundulata, male genitalia; 6, S. biundulata, aedoeagus.