78 BULLETIN 190, UNITED STATES NATIONAL MUSEUM 



SYLVORA ACERNI (Clemens) 



Plai-e 1, Figure 6; Plate 5, Figure 34; Plate 13, Figure 64 



Trochilium acerni Clemens, Proc. Acad. Nat. Sci. Philadelphia, 1860, p. 14. — 

 Morris, Synopsis of the described Lepidoptera of North America, pt. 1, p. 330, 

 1862. 



Aegeria acerni Riley, Sixth annual report on the noxious and other insects of the 

 State of Missouri, p. 107, 1874. — Thomas, Sixth report of the State entomolo- 

 gist on the noxious and beneficial insects of the State of Illinois, pt. 1, 1876, 

 p. 40, 1877; Seventh report (1. c), 1877, p. 173, 1878.— Kelucott, Can. Ent., 

 vol. 13, p. 7, 1881. — Packard, Insects injurious to forest and shade trees, U. S. 

 Ent. Comm. Bull. No. 7, p. 106, 1881.— Saunders, Can. Ent., vol. 13, p. 69, 

 1881.— Riley, Amer. Nat, vol. 8, p. 124, 1874.— Weed, Amer. Nat., vol. 23, 

 p. 1108, pi. 43, fig. 5, 1889.— Riley and Howard, Insect Life, vol. 3, 1890, p. 161, 

 1891. — Beutenmuuler, Ann. New York Acad. Sci., vol. 5, p. 205, 1890. — 

 Bruner, Rep. Nebraska HorL Soc, p. 197, 1891. 



Trochilium acericolum Germadius, Amer. Nat., vol. 8, p. 57, 1874. 



Sesia acerni Hulst, Bull. Brooklyn Ent. Soc, vol. 6, p. 10, 1883.— Lugger, Bull. 

 Minnesota Agr. Exp. Stat., No. 43, p. 188, 1896. — Beutenmuller, Bull. Amer. 

 Mus. Nat. Hist., vol. 8, p. 138, 1896; vol. 9, p. 220, 1897; Mem. Amer. Mus. 

 Nat. Hist., vol. 1, pt. 6, p. 294, pi. 31, fig. 24, 1901. 



Synanthedon acerni McDunnough, Check list of the Lepidoptera of Canada and 

 the United States of America, pt. 2, No. 8727, 1939. 



Male. — Antennae long, slender, slightly dilated toward tips, shiny black 

 or brown-black, pectinations short and very fine. Palpi nearly smooth, 

 orange. Head black, tufted with orange at base, orbits white. Collar 

 orange. Thorax dark orange above, pale orange beneath. Abdomen cov- 

 ered with orange and blackish scales that are more or less mixed, wholly 

 pale yellow beneath ; anal tuft broadly fan-shaped, bright orange, touched 

 with black at the base. Legs yellow, tibiae of hindlegs blue-black between 

 the spurs or sometimes wholly blue-black above. Forewing narrow, costa, 

 veins, narrow marginal border, and large discal mark black ; a small trans- 

 parent area before and a long transparent area behind the discal mark ; 

 apex of wing shaded with pale yellow between the veins, mixed inwardly 

 with blackish scales, suggesting a broken cross band ; the fringes broad, 

 grayish black ; the pale-yellow scaling heavier on the underside of the 

 wings. Hindwing transparent, lightly scaled with pale yellow between the 

 veins at apex, borders narrow, dull black, fringes broad grayish black, 

 discal mark conspicuous, black. 



Female. — Very similar to the male, with wings more contrastingly black 

 and pale yellow ; abdomen blackish above and at the sides in an irregular 

 pattern, due to an admixture of gray scales ; the segments narrowly edged 

 with gray posteriorly ; abdomen beneath wholly pale yellow ; anal tuft 

 short, depressed in center, orange or red. 



Examples of this species very often are discolored by grease ; clean, well- 

 marked specimens are scarce in collections. Submergence in a cleaning 

 medium (benzol or gasoline) for a day or two may be necessary to restore 

 natural color markings before determinations are attempted. 



