Capturing the Crane Fly

Often mistaken for an infamous bloodsucker, the elegant and ephemeral crane fly is actually unrelated to the mosquito and an important part of many different ecosystems.

Wanting to learn more about this interesting insect, the Academy reached out to Maddie Worth, a Drexel student in the Department of Biodiversity, Earth and Environmental Science (BEES) who is working closely with our own Curator of Entomology and BEES Professor, Jon Gelhaus, on a major study of the spectacular biodiversity of the crane fly. 

Tell us more about yourself. 

I am a fifth-year environmental studies and sustainability student with a minor in ecology in Drexel’s Biodiversity, Earth and Environmental Science department. I have been working at the Academy since my first co-op with Dr. Jon Gelhaus when I began working on this Costa Rican crane fly project. My career goals are to continue my entomological research, furthering my education in entomology and hopefully to become a professor and researcher.  

What entomological work do you do at the Academy? 

In my work, I do photographic imaging, identifications, species descriptions and measurements. I begin by imaging the specimens, which is done using a compound microscope with a camera attached, or a Canon DSLR setup with different magnification lenses. The specimens are mostly slide mounted, but some are pinned as well so I have taken images of wings, legs, genitalia, bodies and heads. I typically take multiple images of one specimen, up to 40 shots, then use stacking software to combine the images and develop a photo with all the important characteristics in focus.  

I also record measurements of all of the key body parts being described and imaged, which are used in descriptions. We recently took a trip to the Smithsonian collection and took out loans of type specimens to compare with our species, in order to verify that they are indeed new to science. Once we are confident, we describe the key features of the species and begin to assemble species pages with their corresponding images.     

I had an interest in the co-op position as it surrounded specimen imaging and I have a background in photography. I had no prior experience in entomological work, or any real knowledge of insects, but as I started working with the specimens, I developed an interest in the group of crane flies and wanted to learn more about them. 

What’s so interesting about crane flies? 

When I began learning about the crane flies I became intrigued with how little was known and documented on the genus of crane flies I was imaging, Geranomyia. I was also fascinated by how many of the species were thought to be new to science, and I knew I wanted to be a part of describing them and learning about their characteristics.  

I realized in general how poorly studied insects are, despite being so important to our ecosystems, and I fell in love with the tiny world of insects. 

Crane fly wing, Maddie Worth/ANS

The specimens I have been working with came out of a larger project called ZADBI (Zurqui All Diptera Biodiversity Inventory), which was a project aimed at documenting the diversity of Diptera (true flies) in a Costa Rican cloud forest. The site is called Zurqui de Moravia, and the sampling took place over two years in four hectares of specific land. The project occurred in Costa Rica because there had not been much Diptera work done there previously, and the project creators wanted to learn about and document the fly diversity to demonstrate the importance of biodiversity and conservation.  

Zurqui de Moravia sampling site, Borkent et al. 2018

Through learning about the project and studying the specimens of Geranomyia (one genus of many crane flies collected at the site), we discovered that 20 of 24 species collected are new to science. There were previously only eight species of Geranomyia recorded for Costa Rica, so finding that many species from sampling at one small site was pretty fascinating.  It made me realize how much biodiversity out there is unknown, especially that of crane flies.   

Crane fly genitalia, Maddie Worth/ANS

What challenges do you face in your work? 

There are so many species out there that are undiscovered or very poorly studied, and it is very challenging to document and describe them. This is a challenge for multiple reasons. First of all, there aren’t many trained taxonomists that properly know how to collect and identify species, specifically insect species. There are also issues with identification because many species described in the early 1900s were poorly described and lacked drawings and images, making it difficult to determine whether a species is new or not.  

The literature can also be difficult to find or is not available in English. With all of these challenges, describing new species can take a long time and brings up the question: how efficiently can we describe new species, and can we describe them before they are dying out? This has been an issue in my research due to poorly described species causing us to need to access the type specimens and look at them in person. The Smithsonian holds most of the type specimens we needed but was closed until July to visiting researchers due to the pandemic.  

Some of the many crane fly specimens studied by Worth and Gelhaus at the Smithsonian, Maddie Worth/ANS

What’s the goal of your research? 

The goal of this research is to describe and document these new species of Geranomyia crane flies from Costa Rica. Dr. Gelhaus and I also hope to create a key to the Geranomyia of Central America, making the species more accessible to scientists to study and identify.  

Because there are so many new species discovered in such a small sampling area, we are curious about the overall biodiversity of crane flies in Costa Rica. If there were another four-hectare-sized site sampled somewhere else in Costa Rica, would there be 20 more new species? The biodiversity of Costa Rica seems very unknown and understudied, which is why this project is important in documenting, learning and teaching biodiversity.  

I hope that our findings will help people realize how much biodiversity is still unknown and also help scientists better be able to identify and study Geranomyia crane flies.


  1. Is there any way I can assist? There are a lot in my area and would love to collect them for you or any one working to understand them or collect them.

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