French student pursues doctorate and helps protect citrus industry
Emilie Demard left her native France to study agricultural sustainability in Florida. She is a first-year Ph.D. student in the Department of Entomology and Nematology at the University of Florida based at Indian River Research and Education Center in Fort Pierce, Florida. Emilie is working under the supervision of Dr. Jawwad Qureshi, one of the world’s few citrus entomologists who are well known for his work in monitoring and management of citrus pests, including the Asian citrus psyllid (ACP).
The psyllid is the vector of the huanglongbing (HLB), or citrus greening, a disease that has decreased the state’s signature crop production by more than 50 percent.
To protect citrus from pests and diseases, and in particular, ACP and HLB, citrus producers are now considering crop production under protected structures called Citrus Under Protective Screen, or CUPS. The psyllid is not able to enter fine mesh in the screens used in the construction of CUPS, which protects the fruit from psyllid feeding and transmission of the causal pathogens of HLB.
However, some other pests such as citrus leafminer, scales, thrips, and mites are still able to enter through the CUPS screens and cause damage to citrus trees. Therefore, it is important to understand the incidence of other pest insects inside the CUPS structures. The screen houses provide a different environment for citrus pests and diseases, compared to outdoor environments where trees are produced. Inside the CUPS, scientists can investigate the crop trees and manage any pests.
Emilie is investigating the incidence of mites inside CUPS. Her work includes studies of the mites’ composition, abundance, and distribution, and methods to control the species. Mites are not insects but belong to the arachnid class, which also include ticks and spiders. The mites are harmful to citrus trees because they feed on the leaves and fruit.
Qureshi said Demard’s research contribution would be valuable because the findings will translate to knowledge to develop management techniques to control mite pests. Control methods could include biological and chemical methods for crop protection.
Demard’s scientific interests are in the biological control of pests. Biological control is the use of natural enemies (predators, parasitoids, pathogens, and competitors) to limit the population of a target organism. Biological control is used in several crop production systems and contributes to the sustainability of the system.
Demard’s interest in nature and food began at a young age. She grew up in a city, Saint-Etienne, about three hours south of Paris by train. But it was at her family’s summer home, in Ardèche, in the French countryside, where she cultured a love of nature and for growing food. The family grew garden-to-table produce in their backyard. Potatoes, zucchinis, eggplants, pumpkins, green beans, and lettuce were served at family meals the same day as their harvest.
After primary school, Demard completed the French equivalent of an undergraduate degree in biology, biochemistry, and chemistry, at the University of Jean-Monnet, in Saint-Etienne. She then earned a French master’s degree specializing in crop protection and plant breeding from the National Institute of Agronomy and Food Science, AgroSup Dijon, France.
Demard’s master’s degree thesis involved biological control of the chestnut gall wasp with a specific parasitoid. She did the academic research work in Ardèche, the location of her family’s summer home.
The gall wasp is invasive in France where it destroys fruiting trees and is native to Asia. The pest wasp was identified first in Italy and then found its way to France’s chestnut crop trees. Demard worked on a parasitoid native from Asia as the gall wasp’s natural enemy. The parasitoid laid its eggs inside the gall wasp and then the parasitoids’ young larvae would feed on the gall wasp, killing it.
“It took five years after the first introduction of the parasitoid to see the beginning of the pest population regulation, to start contributing to saving the chestnut trees,” said Demard.
Demard wants to visit many places in the world to observe crop production and to perhaps employ biological control for crop protection. During her graduate work, Demard participated in an international internship in Ecuador. There, she learned how to enhance tropical acidic soils’ fertility by using leguminous and green manures. The farmers in the South American country were restoring a primary forest which had been used as pasture for cattle. Their objective was also to establish and maintain an indigenous botanical garden with orchids and Bromeliads.
“The farmers’ goal was to grow a sustainable, organic garden, orchids and eventually, a new forest,” said Demard.
When the master’s degree was complete, Demard successfully applied for an internship with Glades Crop Protection in Fort Pierce. Her work at the experimental farm involved multipurpose crops, including corn, lettuce, tomatoes, pepper, watermelons, citrus, and beans. The crop research organization had secured contracts testing products distributed by some of America’s largest agrichemical companies. Some of the field trials were with the citrus psyllid and mites. Her contract lasted a year. However, before the conclusion of the internship, she was able to contact Dr. Qureshi and was later accepted for a Ph.D. program at the UF Indian River Research and Education Center (IRREC).
“Dr. Qureshi program also includes work on predators of crop pests, and we expect to find good predators of citrus pest mites,” said Demard.