BROOKINGS, S.D. — To the pedestrian, the Severin-McDaniel Insect Research Collection is just a big room full of cabinets with drawers, filled with dead bugs.
But to Paul J. Johnson, the century-old collection is a living resource, a record of the region’s biodiversity that is vital for agriculture and other research.
Johnson, nearly 65, is an entomologist in his 27th year in research and teaching at South Dakota State University in Brookings. He has curated and maintained the collection since 1993. SDSU’s collection is housed in 118 cabinets, each with 25 drawers of a few dozens to thousands. The collection includes up to 12,000 of the known species in the region.
About 85% of the collection is focused on South Dakota and the Northern Great Plains. Scientists estimate there are some 28,000 insect species in the region.
Of those, less than a half of a percent, or about 100 in the Northern Plains (Canada to Nebraska) are harmful to agricultural crops. Thousands of species are helpful or beneficial.
Johnson said it helps to have large areas of monoculture crops, because “you only have a few species per crop that actually affect each one.” For every species of crop or livestock pests out there, there are predators of that pest.
“You have parasites. You’ve got parasites on the parasites. And you have a wide variety of arthropods that are feeding on decaying parts of crops, that are being beneficial in recycling the carbon and the tissues in the system,” he said.
Entomology was one of the original roles for the so-called “land grant” colleges, including SDSU.
The SDSU collection initially was started in the 1880s, but most of the specimens were lost due to pest and weather damage. (One of the biggest pest problems for insect collections are “dermestid” beetles, or “carpet beetles.”)
The “modern” collection started prior to World War I, when entomology professor Harry Severin was the curator. Severin continued into his retirement in the 1950s and 1960s. Then came Ed Balsbaugh, who migrated to North Dakota State University in the early 1970s. Burruss McDaniel took over and retired in the late 1980s. And then, Johnson.
There is still much to be learned about insects. About 15 years ago, Montana researchers estimated there might be up to 30,000 species of beetles alone in the continental U.S. and Canada.
“By the time you add in the flies, add in the moths, add in the bees and the wasps and ants and the little springtails and everything else that’s out there, the best answer is ‘We don’t know.’ But the 'wild guess' is that in North America, north of Mexico, we’re probably looking at 100,000 to 120,000 species of insects,” he said.
Large insect species are relatively easy to identify. Entomologists continue to identify the “tiny” insects.
“It’s not just the ones in the soil, those that feed inside of plants or, for example, in the seeds of native grasses,” Johnson said. “And the parasites of those insects — we’re still, still discovering lots of new species in those communities.”
“When you’re talking about taxonomic (categorizing and naming) research with collections, there’s never enough material,” Johnson said.
With common crop pests such as corn rootworms, researchers prefer a few specimens from many different areas, because there can be a lot of variation in the structure and biology of the insects.
The SDSU collection gets up to a dozen research loan requests per year.
In late January 2021, Johnson sent a loan of dung beetle specimens to a researcher at the Denver Museum. At the time of a recent tour of the collection, Johnson was preparing a selection of native bees to the University of Manitoba in Winnipeg.
“We have inquiries from all over the world,” he said.
Johnson acknowledges he’s concerned about the future of the collection.
Institutional priorities and graduate student enrollment levels change.
“We really need students who have innate curiosity about the natural world,” Johnson said. “We seem to be in a cycle — not just here at SDSU, but I’ve talked to colleagues in other places — that we’re sort of at a slump in the organismal biology area. We don’t have the numbers coming in that we did 15 to 20 years ago.”
Over the years, SDSU has always had three or four “collection-oriented” taxonomy graduate students at any given time, but always funded from grants, he said. Abigail Martens, a doctorate biology student from northwest Iowa, works with the collection today.
“Curiosity of the natural world is very important in driving a person to spend careers looking at obscure little bugs,” Johnson said. “It’s sort of a prerequisite. Some say, a prerequisite for insanity. It’s not unlike people who have great desires to go fishing, go hunting.”
Instead of going to basic science, the trend today is that students head pest management or lab jobs, or teaching, rather than research. Further, grant sources like the National Science Foundation and U.S. Department of Agriculture have become focused on genomics, the mapping of genetic sequences of organisms. Johnson said historic collections increasingly are helping as a DNA source.
Farms, ranches, tribes
The collection has played an important role in detecting and monitoring invasive species, including velvet longhorn, emerald ash borer, Japanese beetle, oriental beetle, gypsy moth, spotted fruit fly and more. Work was done with support of state agriculture departments and USDA, as well as the U.S. Fish and Wildlife Service and state wildlife agencies.
Johnson thinks the collection will still be here in a decade and beyond, perhaps with more help from volunteers. It’s important for future teachers, students and researchers.
Attitudes are evolving. “Those of us that grew up with the after-effects of the Rachel Carson era commonly think of farms as being these pesticide-driven landscapes that have nothing on them, and that people want everything killed,” Johnson said.
In recent years, Johnson often hears from landowners who are increasingly interested in insect populations. Native American tribes, ranchers and farmers contact him.
“The farmers — the corn and soybean farmers in the eastern part of the state — are interested in doing what they can to help bolster biodiversity in general, environmental settings related to erosion and native plants,” he said. “They’re showing some interest in conservation and rebuilding native communities that are out there — including some of the insects.”