The summer issue of the Cayman compass "Inside out" magazine, discusses the effect that local native plants have on the environmental biodiversity, namely butterflies.
"The butterfly effect"
By Catherine MacGillivray June 16, 2016
Gulf Fritillari / Agrulis vanillae insularis
Fascinated by butterflies from an early age, Joanne Mercille-Ross has created a garden designed to attract Cayman’s fluttering species.
She has dedicated herself to studying and recording the insects, and delights in the numbers which gather around her plants, shrubs and trees.
Joanne’s quest for knowledge about these delicate creatures has seen her develop a website about Cayman’s butterflies. She has also been coached by eminent botanist Dr. George Proctor, collaborated with scientist Dr. Richard Askew and had tutelage from renowned landscape designer Margaret Barwick.
Joanne Mercille-Ross
Cayman has 61 specimens of butterflies, five of which are endemic to the islands, others have “resident” status and some are “vagrants.”
“It is important to record the species of butterflies on all three islands to implement a recovery strategy to protect them if the numbers are down and record the new Cayman ‘residents’,” says Joanne, who describes herself as a self-taught naturalist, or butterfly enthusiast.
Butterflies in Cayman have often mutated to become subspecies, and even endemic specimens which have become specialized to survive the islands’ harsh environment.
“If the same species from Florida, let’s say, would be imported to the island in large enough numbers and bred with the subspecies, it would diminish their ability to survive,” Joanne explains. “Their offspring would have more difficulties finding their food source or be as tolerant of our drought and salt conditions. We have really tough critters.
West Indian Buckeye / Junonia genoveva
“Seasonal storms bring new butterflies to the Cayman Islands from nearby mainland places such as Florida, and other islands such as Cuba or Jamaica. They are called ‘vagrants.’ Some of these ‘vagrants’ establish themselves here, but some cannot establish or reproduce.”
Originally from Quebec, Canada, Joanne has been studying butterflies in Cayman since 1996.
“I don’t have a degree in entomology or botany but my curiosity led me to research the species of butterflies that are on the island and the correlation between their food source, host and nectar plants, to ensure their survival,” she says. “I realized that the local native flora was most important to them. Enthusiasts often stimulate grassroots movement that, in turn, raises issues and brings solutions; this leads to awareness and conservation.”
When first moving to Grand Cayman, a number of butterflies were caught in the screened porch of her house, two of them turning out to be first recorded sightings on the island: Calisto herophile (Riglet) and Calpodes ethlius (Canna skipper).
Since then, she has sighted other rare speciesin her garden include the Anteos maerula (yellow angled sulphur) and the Chlorostrymon maesites (Amethyst hairstreak).
Mentoring
Gulf Fritillari / Agrulis vanillae insularis
Joanne often collaborates with Dr. Askew, a visiting scientist, who spends time on the island studying butterflies. Dr. Askew wrote the reference book “Butterflies of the Cayman Islands,” with Cayman resident Ann Stafford, partially illustrated by his photographer wife Tish.
Joanne was also mentored about the relationship between butterflies and their host plants by Dr. Proctor, who passed away in October 2015, aged 95. The author of “Flora of the Cayman Islands” he was renowned for his scientific knowledge, working at both the Institute of Jamaica and lecturing at the University of the West Indies in Kingston.
In fact, it was at Joanne’s invitation that he visited Cayman in 2002 after a 20-year hiatus, discovering many new records and specimens, which led to a new edition of the book.
“Dr. Proctor was a very good teacher,” she says. “He took the time to explain the intricacies of plant families, their scientific keys and classifications with fun anecdotes in his storytelling fashion.”
Native plants
False Barred Sulphur / Eurema elathea
For butterflies to survive and thrive in Cayman it is important to have native plants to host the insects. As such, Joanne has been closely involved in setting up the native plant nursery at the Queen Elizabeth II Botanic Park.
Joanne started creating her own butterfly garden following a year gleaning knowledge from Margaret Barwick, who was at that time designing the gardens at the Health City Cayman Islands hospital complex.
“The idea behind my butterfly garden began as a study to apply Margaret’s landscape design idea,” she recalls. “This was to recreate local flora with texture, form and color in my garden and limit my ‘host and nectar plants’ selection to invite butterflies with mostly local native plants in my landscape, blending exotics in my design for ‘punch’ value.
“I inevitably will forsake design to feed my butterflies but I can still design with some texture, form and color. My knowledge of our flora and butterflies allows me to landscape with native plants that are specific to extreme conditions such as ocean exposure where few plants will be able to grow in a sand substrate, salt spray, drought and full sun.”
Careful of chemicals
And while Joanne’s garden is not completely organic, she is careful of chemical overuse.
“Nature’s balance is so precarious; weed killer will affect the cycle of life for butterflies and birds, lizards, frogs, etc. disrupting the food chain,” she says. “I use mostly neem tree oil, which is a short-term natural insecticide for infestation control. It washes away easily and it is not systemic like other chemicals used on plants.”
Joanne’s garden is by the sea on the south coast, where is it quite an achievement to grow plants in the salty environment.
“What gives me the most delight in my garden is to see which butterflies come to visit for breakfast and which join us at cocktail hour,” she says.
For further information about Cayman’s butterflies and host plants, visit Joanne’s websites caymanbutterflies.org and caymanflora.org.