200 JOURNAL OF THE LEPIDOPTERISTS' SOCIETY aggregation often began thrashing for up to 20 min and that often appeared to prevent fly contact with the larvae. As noted in field observations, some larvae attacked by the flies immediately dropped to the ground.

NANCY E. STAMP, Department of Biological Sciences, State University of New York, Binghamton, New York 13901, AND M. DEANE BOWERS, University of Colorado Museum and Department of E.P.O. Biology, Campus Box 334, University of Colorado, Boulder, Colorado 80309.

Received 12 August 1989; revised and accepted 23 June 1990.

Journal of the LepIdopterists' Soctety 44(3), 1990, 200-201

URBAN BIOLOGY OF MARINA (REAKIRT) ()

Additional key words: auriculata, myrmecophily, predators, parasitoids, ecology.

Leptotes marina (Reakirt) is a widespread Iycaenid , ranging from south­ western United States to northern Central America. Ecologically versatile, it occurs in a wide range of habitats from xeric deserts to coniferous forests or tropical lowlands. As early as the I 920s, L. marina had become a common backyard in southern California; J. A. Comstock (1930:177, of California, published by the author, Los Angeles, 334 pp.) reported the ornamental Wisteria (Fabaceae) as the larval host in these situations. Since that time, L. marina has become increasingly urbanized. Although larvae feed on Fabaceae in native situations, the primary host in urban environments today is the perennial Cape Plumago (Plumbago auriculata Lam.; Plumbaginaceae), a bush introduced from South Africa and used widely as a garden ornamental and in freeway landscaping. In contrast to the spring blooming Wisteria, P. auriculata may bloom year round, providing larval resources throughout the year. An urban site approximately 2.5 km east of Imperial Beach, San Diego County, Cal­ ifornia, harbors a large population of L. marina, and this locality was the source of the following observations. Eggs are laid singly on the calyx and developing buds of P. auriculata. The young larva bores a hole into the bud near the base, where it feeds primarily on plant reproductive tissue. Later instars may devour nearly the entire bud or developing seeds. Flower petals are eaten rarely; larvae were never observed to feed on foliage. A single bush of P. auriculata may support a substantial population of the butterfly without exhibiting no­ ticeable damage from larval feeding. The butterfly appears to be continually brooded. Although adults may be taken throughout the year, population density is conspicuously depressed from December to February or March in most years. All larvae observed in the field (n = 15) were closely associated with Argentine ants [Iridomyrmex humilis (Mayr); Hymenoptera: Formicidael; ants were either on or within a centimeter of larvae. Larvae were never observed in the absence of ants; three to five ants on a single inflorescence always indicated the presence of one or more larvae. Larvae reared in the laboratory in cardboard cartons at ambient temperature developed normally in the absence of ants. As reported previously for L. marina and for many other Iycaenids (Ballmer, G. & G. Pratt 1989, J. Res. Lepid. 27:1-81), larval coloration and markings are extremely variable. Of 20 larvae brought into the laboratory, 3 produced Single braconid parasitoids (Cotesia sp.; Hymenoptera: Braconidae: Microgastrinae) that pupated in silken white cocoons attached either to the host material or to the paper-towel substrate. In the VOLUME 44, NUMBER 3 201 laboratory, larvae of L. marina left the host material to pupate. Pupae were attached to the substrate by a cremaster and a silken girdle. The pupation period lasted seven days. The only nectar source at which I observed adults was Brazilian Pepper (Schinus terebinthifolius Raddi; Anacardiaceae). The small white flowers of Brazilian Pepper attract a large number of hymenopteran and dipteran visitors, but few, if any other . Ornamental Cassia sp. (Fabaceae) and Lantana sp. (Verbenaceae) are used occasionally as perching substrates, but I never observed L. marina nectaring on these plants. Although the butterfly literally may swarm around the host, I never observed L. marina nectaring on the larval host. This probably is due to the long corolla compared to the length of the butterfly's proboscis (Opler, P. & G. Krizek 1984:32, Butterflies east of the Great Plains, Johns Hopkins Univ. Press, 294 pp.). A small noctuid larva, inadvertently collected while gathering inflorescences of plum­ bago, produced an adult of Heliothis virescens (Fabricius) (Noctuidae). This was the only other lepidopterous larva observed feeding on plumbago. On 13 August 1989, 1130 hours, I observed a female L. marina that had been captured by a green lynx spider [Peucetia viridans (Hentz); Oxyopidae] on a Cassia bush. These spiders ambush their prey, which consists primarily of moths, both adults and larvae, but also many other kinds of (Whitcomb, W., M. Hite & R. Eason 1966, J. Kansas EntomoI. Soc. 39:259-267). is one of few native North American butterflies that has benefited from the activities of man by its remarkable switch to a new larval host introduced from South Africa and to a nectar source and an ant introduced from South America, none of which are closely related to the butterfly's native resources. This flexibility undoubtedly has led to an expansion in range, at least ecologically and temporally, over the past 60 years, resulting in the butterfly's invasion and successful colonization of urban environ­ ments. I thank Roy Snelling for identifying the ants associated with the larvae, and James Whitfield for identifying the parasitoids. I gratefully acknowledge Sterling Mattoon and Ronald Flaspohler for many helpful suggestions that improved the quality of this brief manuscript.

JOHN W. BROWN, Entomology Section, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007.

Received for publication 28 November 1989; revised and accepted 18 June 1990.

Journal of the Lepidopterists' Society 44(3), 1990, 201-202

NORTHWARD DISPERSAL OF EUPTOIETA CLAUDIA (NYMPHALIDAE) IN CALIFORNIA AND NEVADA IN 1988

Additional key words: distribution, biogeography.

The Variegated Fritillary, Euptoieta claudia (Cramer), is a highly dispersive species whose late-summer range in North America frequently extends far beyond those areas where it is a permanent resident. Because of its frequent and occasionally massive north­ ward movements, dot maps of its distribution tend to disguise its transient nature. J. A. Scott (1986, The butterflies of North America, Stanford University Press, Stanford, Cal­ ifornia, pp. 335-336) maps its transient range as covering most of North America, but it is conspicuously unmapped on the Pacific Coast north of the California Transverse Ranges. Except for a passing reference to a record in Mono County (J. A. Comstock, 1927, Butterflies of California, published by the author, Los Angeles, California, 334 pp.), the