The Biodiversity of Butterflies in Florida
Jun 17, 2015 08:25AM ● Published by Corinne Moore
By William R. Cox
South Florida is blessed with an abundance of butterflies. The U.S. National Park Service reports that more than 90 species of butterflies have been recorded in Everglades National Park. This is more than half of all the known butterfly species in Florida.
Butterflies and moths are insects of the phylogenetic order Lepidoptera, derived from the Greek lepidos for scales and ptera for wings. Their scaled wings distinguish them as a group from all other insects. There are approximately 10,000 species of Lepidoptera in North America.
The great biodiversity of butterflies in South Florida can be attributed to the year-round subtropical climate and its varied habitats. For example, cypress forests, mangrove estuaries, pine flatwoods, palmetto prairies, coastal beaches, hardwood hammocks, campgrounds and roadsides all provide habitat for butterflies in the Fort Myers and Sanibel and Captiva island areas. They can be seen fluttering around during the warmest part of the day and are more abundant during the summer.
Despite the remarkable biodiversity of butterflies in South Florida, some species are in decline, and some are believed to be extinct, such as the Zestos skipper (Epargyreus zestos) and rockland grass skipper (Hesperia meskei pinocayo). Other species have been severely restricted in their range and now occupy very small areas in South Florida. The monarch (Danaus plexippus), one of the most abundant and popular butterflies, is also suffering major range restrictions and population declines in Florida and North America.
The tragic loss of butterfly abundance and biodiversity degrades the health of our ecosystem. Habitat loss, butterfly collecting, heavy use of pesticides and herbicides, natural disasters and the introduction of nonnative plants and animals all contribute to the population decline of Lepidoptera. For example, the elongate twig ant (Pseudomyrmex gracilis) was found in Dade County Florida in 1960 and continues to be introduced into home gardens to feed on live insects, especially Lepidopteran larvae (butterfly and moth caterpillars). The planting of invasive nonnative vegetation such as scarlet milkweed (Asclepias curassavica), blue porterweed (Stachytarpheta cayennensis), Christmas cassia (Senna pendula var. glabrata) and lantana (Lantana camara) is not advisable as these plants aggressively outcompete other native plants that are more beneficial as host and nectar plants for butterflies. Native milkweeds are very important to monarch and queen (Danaus gilippus) butterflies. More than 100 milkweed species occur in North America. They grow best in disturbed habitats, and approximately 90 percent of milkweeds grow in agricultural landscapes. The increasing use of herbicides in agriculture has led to milkweed loss and thus butterfly decline.
What can you do to help in the conservation of monarchs and other butterflies? Besides limiting the use of herbicides and not planting invasive vegetation, you can create a butterfly garden. Most monarchs in South Florida are nonmigratory because of the mild climate. This means these butterflies will spend their lives in a very small area with specific habitat requirements. It is very important to consider adjacent plant communities (prairies, forests, parks) when choosing plants for your butterfly garden. Butterflies need both host and nectar plants, so you need to plant native host and nectar plants that represent the native vegetation found in adjacent habitats.
These are not always the most beautiful flowering plants recommended by local nurseries. Host plants, such as milkweeds, are usually devoured by butterfly larvae, and this may be disturbing to some gardeners. Applying pesticides to kill the butterfly larvae (caterpillars) or picking the larvae off the host plants is counterproductive, however. I have observed the leaves of the milkweeds in our garden completely consumed, and the plants have totally recovered. The larvae will move to other plants to transform into pupae (chrysalis) and emerge as adults.
Eight species of milkweeds are native to South Florida. One of the most beneficial is butterfly weed (Asclepias tuberosa), which provides more nutrients to monarchs than other milkweeds. Other native larvae host plants for monarchs are swamp milkweed (A. incarnata) and longleaf milkweed (A. longifolia). Native nectar plants for monarchs include mistflower (Conoclinium coelestinum), flat-topped goldenrod (Euthamia caroliniana), yellowtop (Flaveria linearis) and cat’s tongue (Melanthera nivea). It is also beneficial to identify butterflies by the use of binoculars and photography rather than collecting them as was often suggested by earlier field guides and textbooks.
For more information, see nps.gov/ever/learn/nature/butterflies.htm.
William R. Cox has been a professional nature photographer and ecologist for more than 35 years. Visit him online at williamrcoxphotography.com.
Despite the remarkable biodiversity of butterflies in South Florida, some species are in decline, and some are believed to be extinct.