40 
Psyche 
[March-Junc 
Croesia forskaleana (Linnaeus) 
Phalaena Tortrix forskaleana Linne, 1758, Syst. Natur., ed. 10, p. 531. 
Argyrotoxa forskaleana: Klots, 1941, Bull. Brooklyn Entomol. Soc., 36: 126; 
Beckwith, 1962, Sci. Tree Topics, 2(9): 15. 
Croesia forskaleana: Obraztsov, 1956, Tijdschr. v. Entomol., 99 : 127 
(synonymy) ; MacKay, 1962, Canadian Entomol., Suppl. 28: 10 (larva). 
Diagnosis. — The ochreous yellow forewings of this species differ 
from the lemon yellow ones of native Nearctic species of Croesia . 
The delicate, reddish reticulation and the transverse blackish mark 
— which varies from a thin, median line, outwardly angulate in the 
cell, to a broad blotch on the mid dorsum — also distinguish C. 
forskaleana (figs. I and 2). Croesia semipurpurana (Kearfott) and 
C. curvalana (Kearfott) are native species that sometimes show 
blackish dorsal marking, but in them it is expressed as a broad blotch 
in the tornal region. All native species of Croesia have curving 
bands of shining rosaceous or lavender across the forewing, while 
C. forskaleana does not. 
Male and female genitalia of C. forskaleana are figured by Pierce 
and Metcalfe (1922). 
Geographic distribution. — Croesia forskaleana ranges widely in 
the Old World, from Great Britain and central and southern con- 
tinental Europe to the Caucasus (Meyrick 1895; Obraztsov 1956). 
For the United States, Klots (1941) gave a 1939 record from 
western Long Island, New York, and cited W. T. M. Forbes as 
authority for specimens dating back to 1934 from the northeastern 
tip of that island. Our data, which include an earlier record (1932) 
for the latter area, suggest a sequence of more or less steady spread. 
Croesia forskaleana was established in eastern Long Island by the 
early 1930’s and at the western end of the island and adjacent main- 
land New York (Westchester County) by the late 1930’s. After 
two more decades — in which there were no mainland records beyond 
the New York City area — • it was collected in westcentral Connecti- 
cut (1959), central Connecticut (1962), and east coastal and central 
New Jersey (1962) (fig. 5). Together, these records point to a 
multidirectional expansion of the moth on the mainland. 
Croesia forskaleana was found on a second island, Martha’s Vine- 
yard, Massachusetts, in 1944. It probably got there at about that 
time because it did not turn up in the course of a long survey of the 
Lepidoptera of Nantucket and Martha’s Vineyard islands (Jones 
and Kimball 1943), which was “completed” in 1942. Several points 
attest to the exhaustiveness of that survey: “. . . the Marthas 
Vineyard records are based [principally] upon the observations and 
