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Publication #EENY 427

Yucca Giant-Skipper Butterfly, Megathymus yuccae (Boisduval & Leconte) (Insecta: Lepidoptera: Hesperiidae)1

Jaret C. Daniels2

Introduction

As its name implies, the yucca giant-skipper, Megathymus yuccae (Boisduval & Leconte), is a large and robust-bodied butterfly. It may be encountered in a variety of habitats that support yucca including coastal areas, dunes, scrubs, sandhills, pine flatwoods, old fields, and utility corridors.

Distribution

The yucca giant-skipper is a resident across southern portions of the United States from North Carolina to California and south to northern Mexico. In Florida, it can be found throughout the northern two thirds of the state. Despite its broad geographic distribution, the yucca giant-skipper is quite local and uncommon. Adults are seldom encountered in numbers.

Description

Adult: The yucca giant-skipper is a medium-sized butterfly with a stout, robust body. Adults have a wingspan range of 50 to 75 mm. The sexes are similar although females are generally larger than males and have wider, more rounded forewings. The wings above are dark brown. The forewings are elongated with a variable yellow outer band. The hindwings in males have a single yellow marginal border. Females have an additional yellow spot band across the outer portion of each hindwing. The hindwings below are dark blackish-brown with violet-white frosting and a prominent triangular white spot along the leading margin.

Figure 1. 

Dorsal view of an adult yucca giant-skipper, Megathymus yuccae (Boisduval & Leconte).


Credit: Jaret C. Daniels, University of Florida
[Click thumbnail to enlarge.]

Figure 2. 

Ventral view of an adult yucca giant-skipper, Megathymus yuccae (Boisduval & Leconte).


Credit: Jaret C. Daniels, University of Florida
[Click thumbnail to enlarge.]

Figure 3. 

Egg of the yucca giant-skipper, Megathymus yuccae (Boisduval & Leconte), on Adam's needle, Yucca filamentosa L.(Agavaceae).


[Click thumbnail to enlarge.]

Life Cycle

The yucca giant-skipper produces one generation each year from February to May depending on location. Adults have a fast, powerful flight and can literally be heard whizzing past. Males perch on low vegetation or on the ground near patches of the larval host to await passing females. Adult yucca giant-skippers do not visit flowers, and it is unknown if they occasionally utilize other food resources.

The young larvae feed on host leaves and construct small individual silken shelters. Older larvae bore into the plant crown and feed within the root, constructing a prominent silken tent or chimney at the opening of the burrow. Relatively little is known about the yucca giant-skipper's behavior, population biology or exact habitat requirements.

Figure 4. 

Tent constructed by a larva of the yucca giant-skipper, Megathymus yuccae (Boisduval & Leconte), on Adam's needle, Yucca filamentosa L.(Agavaceae).


Credit: Jaret C. Daniels, University of Florida
[Click thumbnail to enlarge.]

Hosts

Females lay the large amber-brown eggs singly on leaves of Adam's needle, Yucca filamentosa L. (Agavaceae), and moundlily yucca, Yucca gloriosa L. Other yucca species may also be utilized.

Figure 5. 

Adam's needle, Yucca filamentosa L.(Agavaceae), a host plant of the yucca giant-skipper, Megathymus yuccae (Boisduval & Leconte).


Credit: Jaret C. Daniels, University of Florida
[Click thumbnail to enlarge.]

Selected References

  • Cech R, Tudor G. Butterflies of the East Coast: An Observer's Guide. 2005. Princeton University Press, Princeton, NJ. 345 pp.

  • Daniels JC. Butterflies of Florida Field Guide. 2003. Adventure Publications, Cambridge, MN. 250 pp.

  • Kimball CP. 1965. The Lepidoptera of Florida; an annotated checklist. Arthropods of Florida and Neighboring Land Areas Vol. 1. Florida Department of Agriculture and Consumer Services, Division of Plant Industry. 363 pp.

  • Minno MC, Butler JF, Hall DW. 2005. Florida Butterfly Caterpillars and Their Host Plants. University Press of Florida, Gainesville. 341 pp.

  • Minno MC, Emmel TC. 1993. Butterflies of the Florida Keys. Scientific Publishers, Gainesville. 168 pp.

  • Opler P, Krizek G. 1984. Butterflies East of the Great Plains: An Illustrated Natural History. Johns Hopkins University Press, Baltimore, MD 322. pp.

Footnotes

1.

This document is EENY-427, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: February 2009. Reviewed February 2012. This document is also available on Featured Creatures website at http://entomology.ifas.ufl.edu/creatures. Please visit the EDIS website at http://edis.ifas.ufl.edu. Additional information on these organisms, including many color photographs, is available at the Entomology and Nematology Department website at http://entnemdept.ifas.ufl.edu/.

2.

Jaret C. Daniels, assistant professor, Entomology and Nematology Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.


The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.