common name: little metalmark
scientific name: Calephelis virginiensis (Guérin- Ménéville) (Insecta: Lepidoptera: Riodinidae)

Introduction - Distribution - Description - Life Cycle and Biology - Hosts - Selected References

Introduction

The little metalmark, Calephelis virginiensis (Guérin- Ménéville), is one of three allopatric metalmarks found in the eastern United States. Although the little metalmark is one of our tiniest butterflies, it is one of our most beautiful. It is the only metalmark found in the southeastern coastal plain.

Distribution

Southeastern coastal plain from southeastern Virginia to eastern Texas in uplands and marginal wetlands, sandhills, flatwoods, pine savannas, prairies, and on roadsides.

Description

Adults: The wings vary in color from rusty orange to orange-brown and have metallic silver lines on the wings – the characteristic from which the family gets the common name "metalmarks".

adult

Eggs: The flattened eggs are reddish-brown with white sculpturing.

egg

Larvae: Caterpillars are light-green, stippled with many tiny white dots. There are dorsal and lateral rows of long white setae on each side and a rust-brown sub-dorsal spot on each side on abdominal segments two through seven.

larva, dorsal view

larva, dorso-lateral view

Pupae: The pupae are green with dorsal and lateral rows of black spots. The pupa is covered with setae from the last instar larva– possibly for protection from predators or parasitoids.

pupa

Life Cycle and Biology

This metalmark is common throughout Florida, except for the Keys. At least three generations are produced each year in northern parts of its range and many flights all year in Florida (Scott 1986). It is most common during late summer and fall in Florida, but caterpillars are present from March through November (Minno et al. 2005).

Little metalmarks are low-flying and are not commonly seen until they land and rest with their wings outstretched. Adults tend to orient themselves in an upside-down position when resting. Males patrol for females but their patrolling is fairly localized. Flat-flowered composites (Asteraceae) seem to be the preferred nectar sources.

Eggs are laid singly on the underside of the host leaves. Caterpillars feed mostly at night (Cech and Tudor 2005) on the undersides of the leaves, but leave the translucent upper cuticle intact. These small circular windows in the leaves are a good sign to look for when searching for the caterpillars. Partly grown caterpillars are probably the over-wintering stage (Opler and Krizek 1984).

Hosts

Little metalmark caterpillar host plants are herbs in the Aster Family (Asteraceae) including yellow thistle, Cirsium horridulum Michx., vanillaleaf, Carphephorus odoratissimus J.F.Gmel.) H.Hebert (Minno et al. 2005, Wagner 2005) and sometimes climbing hempvine, (Mikania scandens) (L.)Willd. (Minno et al. 2005). Caterpillars are especially cryptic on the undersides of the leaves of yellow thistle where their hairs blend in with the long white hairs of the plant.

Yellow thistle flowers vary in color and may be white, yellow, or purple.

yellow thistle

yellow thistle

Photographs of vanillaleaf are available at the Institute for Systematic Botany (University of South Florida) Web site: http://www.plantatlas.usf.edu/images.asp?plantID=3092#.

climbing hempvine

Selected References


Authors: Donald W. Hall, University of Florida; Marc Minno, St. John's River Water Management District; and Jerry F. Butler, University of Florida
Photographs: Jerry F. Butler and Donald W. Hall, University of Florida; and Marc C. Minno, St. John's River Water Management District
Project Coordinator: Thomas R. Fasulo, University of Florida
Publication Number: EENY-407
Publication Date: May 2007
Copyright 2007 University of Florida

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