A tribute to Thelma Perry

Microbiologist & mycology research pioneer

From left to right, colleagues J. Robert Bridges, John C. Moser, Meredith Blackwell, and Thelma J. Perry at the time they were working on Perry’s observation of Pyxidiophora. Photo courtesy of Kier Klepzig, photographer unknown.

Thelma J. Perry was one of the first researchers to explore the remarkable relationships between bark beetles and their mutualistic fungi.

Perry’s story is a monument to determination. An African American, she was born April 30, 1941 and raised in Birmingham, Alabama. After Perry graduated from high school, she attended Xavier University in New Orleans but did not complete a degree. She eventually returned to school at age 37 and completed a Bachelor’s degree in biology at Louisiana College.

In the late 1960s, Perry began working as a biological laboratory technician at a USDA Forest Service Southern Forest Experiment Station (a precursor to the Southern Research Station) at Pineville, Louisiana. The value of Perry’s discoveries and unique talent as a researcher were recognized by the Forest Service, and she was promoted to microbiologist, a professional position in the agency.

Perry had an exceptional eye for detail and was a meticulous observer of the relationships between major bark beetle pests and their associated microbes. Perry focused her studies on microscopic fungi that are transported to new host trees in bark beetle mycangia, specialized pouches where beetles carry symbionts that can be critical for their reproduction.

face of a beetle
The southern pine beetle is about the size of a grain of rice. It carries symbiotic fungal species in specialized mouth pockets called mycangia. Photo courtesy of Bugwood.org.

For example, she observed that fungal filaments (hyphae) sprouted from the mycangia of dead beetles but not live insects, providing evidence that beetles produced secretions that kept the fungal propagules in a single-celled, yeast-like form for transport and dissemination.

Her studies formed the foundation of a major body of research on the relationships of Dendroctonus bark beetles (major killers of North American conifers) with their symbionts, and she greatly advanced our understanding of insect-fungal symbioses.

Perry contributed to the discovery and description of a widely distributed species of bark beetle-transmitted fungus that infests stressed pine roots (Leptographium terebrantis Barras & Perry) and is suspected of playing a role in pine decline syndromes. In recognition of her contributions to mycology, a species of bark beetle associated fungus was named this year in her honor: Entomocorticium perryae.

Perry was generous in helping other mycologists – both budding and experienced – benefit from her observations. During his graduate studies, research entomologist Brian Sullivan visited Perry’s lab to learn about her extensive observations of bark beetle-fungal symbioses. He recalls having never before (or since) spoken with a mycologist with such detailed knowledge of the topic and a willingness to share it. When Sullivan incorrectly addressed her as ‘Dr. Perry,’ she chuckled and said, “Oh no, I am just a microbiologist!”

fungus under a microscope
Fungus basidiomycente in mycangium of southern pine beetle, discovered but not described. Photo by Thelma Perry, courtesy of Brian Sullivan, USDA Forest Service.

During that visit, Perry provided Sullivan with extensive, written notes of observations, hypotheses, and research directions that – if given the opportunity – she wished to pursue. Sullivan thought it remarkable that she offered these documents to him, as it is more typical for scientists to be highly protective of such information.

This year, Sullivan and Meredith Blackwell, emeritus professor at Louisiana State University, submitted these documents to the Hunt Institute for Botanical Documentation. Unfortunately, most of Perry’s observations and associated hypotheses were never pursued further or published due to her laboratory’s emphasis on applied studies.

Perry endured personal tragedies in the last fifteen years of her life, including a six-year fight with cancer that caused her death on February 10, 1998. She is buried in the Carver Memorial Gardens Cemetery in Birmingham.

This story is excerpted from the original, which was published by the Mycological Society of America. Read the original version of the story.

For more information, email Brian Sullivan at brian.sullivan2@usda.gov.

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