FORT PIERCE, Fla. — In Patricia Prade’s native Brazil, Brazilian peppertree is a natural tree that fruits red peppercorns. But, in Florida, the tree is the state’s most serious invasive plant, where it consumes more than 700,000 acres of the state’s natural landscapes and displaces Florida’s natural species.
This year, Prade completed a Ph.D. in entomology at the University of Florida’s Institute of Food and Agricultural Sciences Norman C. Hayslip Biological Control Research and Containment Laboratory (UF/IFAS-BCRCL) in Fort Pierce, Florida. The laboratory is one of only three that specialize in biological control of invasive species in Florida. Prade’s thesis involved biological control of the Brazilian peppertree. Its title is “The Biological Control of Brazilian Peppertree in Florida.”
Biological control is a method to control invasive species with its natural enemies from the invasive species’ natural habitat. In Brazil, Brazilian peppertree (BP) is a much smaller plant that does not grow out of control as it does in Florida. The tree is a normal part of the South American landscape because its natural enemies are nearby to feed on the tree and maintain its normal size, said Prade.
“Biocontrol is a recommended technique to control Brazilian peppertree in Florida because of the extension of the areas covered with BP, the costs associated with chemical and mechanical control in such a big area are prohibitive, and some of these areas with high BP infestation are environmentally sensitive, like the Everglades National Park,” said Prade.
The laboratory in which Prade did most of her work is at the UF/IFAS Indian River Research and Education Center, or IRREC, one of 12 research centers throughout Florida. Directing her studies was Carey Minteer, assistant professor of entomology at IRREC. Prade completed both a bachelor’s and a master’s degree in forestry engineering at the Regional University of Blumenau in Brazil. In Brazil, Prade’s master’s studies were co-supervised by Rodrigo Diaz, a former postdoctoral scientist working with Bill Overholt, former research leader for the BCRCL’s weed biocontrol program and now an emeritus professor of entomology. Diaz met Prade while visiting southern Brazil in 2013 in search of new potential biological control species for study at the UF lab in Fort Pierce.
All around the laboratory, and on state-owned and private lands throughout Florida, the Brazilian peppertree outcompetes natural plants for water and space. But last year, after years of extensive research and following state and federal regimentations, teams of scientists from the U.S. Department of Agriculture, the Florida Department of Agriculture and Consumer Services, and the University of Florida released an insect as a biological control agent statewide against the Brazilian peppertree.
The insect is the Brazilian peppertree thrips, Pseudophilothrips ichini, a tiny black insect that feeds on BP trees’ stems. The thrips were released at state parks and on ranches throughout the state in 2019.
“Work with the BP thrips started around 1994,” said Prade. “Many years of hard work and several highly skilled researchers from the U.S. and South America made the releases in 2019 possible. I did an experiment with the thrips last year.”
Other work Prade did to make the BP biological control effort successful was published in scholarly scientific journals. Prade is the lead author of one research journal article about a second biological control insect against BP, the yellow Brazilian peppertree leafgaller. Biocontrol Science and Technology published an article titled Galls induced by Calophya latiforceps. An additional journal article to which she contributed was published in Florida Entomologist. The article entitled Taxonomy of Calophya associated with Brazilian peppertree, talks about all the species of the leafgallers that damage Brazilian peppertree in Brazil. UF/IFAS scientists expect to release the leafgaller to control the BP in Florida in 2021.
Prade wrote three extension online publications for UF’s Department of Entomology Featured Creature database. The documents outline and detail the BP thrips, which was released last year and is damaging the invasive tree throughout the state, the yellow BP leafgaller, an insect soon to be released in Florida, and the salvinia weevil, a worldwide successful biological control agent of giant salvinia. All three extension documents (BP thrips, yellow BP leafgaller, and salvinia weevil) were published on UF’s Electronic Document Information System, or EDIS. Prade also co-authored with Minteer and colleagues a book for the Florida Exotic Species Pest Plant Council (FLEPPC) on the integrated pest management guide for BP, a scientists’ efforts to control Florida’s most serious invasive plant with biological controls.
Prade’s awards as a UF/IFAS graduate student include the Julia Morton Invasive Plant Research Grant Program, and the Kathy Craddock Burks Education Grant, both sponsored by the FLEPPC. Each of the awards was presented to her in 2017. She received a Travel Award, sponsored by the University of Florida Graduate Student Council, to attend the Hemiptera-Plant Interactions Symposium in 2017. In 2016, Prade won a mini-grant for her research, sponsored by the Florida Fish and Wildlife Conservation Commission Invasive Plants Section. Also, in 2016, Prade garnered two presentation awards for graduate student competitions. She placed second for an academic poster presentation at the International Congress of Entomology in 2016, and third for an oral presentation at the FLEPPC Annual Symposium. Prade also mentored students, participated in several outreach events organized by Minteer, and Skype a Scientist.