- Author: Kathy Keatley Garvey
If you're a gardener, you're aware that nematodes are "microscopic, eel-like roundworms" and that "most troublesome species in the garden are those that live and feed within plant roots most of their lives and those that live freely in the soil and feed on plant roots," according to the UC Integrated Pest Management Program website on nematodes.
If you attended the ninth annual UC Davis Biodiversity Museum Day, you learned hands-on information from nematologists Christopher Pagan and Corwin Parker, doctoral students who study with major professor Steve Nadler, professor and chair of the UC Davis Department of Entomology and Nematology.
Pagan and Parker held forth at their display in the Academic Surge Building, where they fielded questions about nematodes and showed specimens to the visitors. The nematode collection was one of 13 museums or collections featured at the Biodiversity Museum Day, always held the Saturday of Presidents' Weekend.
Many visitors asked what nematodes are, they related.
Other common questions asked:
- Do I have nematode parasites?
- How dangerous are nematode parasites/can they kill you?
- How long do they live?
- How many species ofode are there?
- Are soil nematodes good or bad for my garden?
Parker shared some of the answers:
Do I have nematode parasites?
Probably not unless you've been traveling a lot. The most common nematode parasite of humans in the US is pinworm which most children get, but not adults. Worldwide however, hundreds of millions of people are infested with parasites including Ascaris, hookworm, and whipworm.
How dangerous are nematode parasites/can they kill you?
Nematode parasites are usually relatively benign unless you have a lot of them. Potentially fatal exceptions do exist, such as zoonotic infections of rat lungworm and raccoon roundworm, but those are rare.
How long do nematodes live?
It depends on the species and life history. Parasitic nematodes can live for a long time, while most free-living nematodes have relatively short lifespans. Some nematodes that live in harsh environments such as deserts can extend their lives by going into a state of suspended animation until environmental conditions are optimal.
How many species of nematode are there?
More than 30,000 described species, but it's estimated there are more than 1 million total.
Are soil nematodes good or bad for my garden?
Most soil nematodes are neutral to beneficial for your garden. They're an integral part of the soil ecosystem and help with nutrient cycling, and some kill of root-feeding insects. There are some plant-parasitic nematodes, but most don't cause significant damage.
UC Davis Biodiversity Museum Day
In addition to the nematode collection, the UC Davis Department of Entomology and Nematology showcased the Bohart Museum of Entomology and the Häagen-Dazs Honey Bee Haven. Other participating museums or collections at this year's Biodiversity Museum Day: the Botanical Conservatory, Arboretum and Public Garden, California Raptor Center, Museum of Wildlife and Fish Biology, Paleontology Collection, Phaff Yeast Culture Collection, Viticulture and Enology Culture Collection, Anthropology Museum, Center for Plant Diversity, and Marine Invertebrate Collection.
If you missed it, calendar the 10th anniversary Biodiversity Museum Day in 2021. The event always takes place the Saturday of Presidents' Day Weekend.
- Author: Kathy Keatley Garvey
The U.S. Department of Agriculture's (USDA) Agricultural Research Service (ARS) and Pheronym, a company in Alachua, Fla., that develops and produces nematode pheromones, have announced plans to send nematodes (small round worms) to the International Space Station as early as this year.
The news, announced Feb. 20 on the ARS website, may have been overlooked by many ("What's a nematode?") but not by nematologists and other scientists.
The headline: "Starship Nematode."
"The mission represents a look into the future where food crops will be grown in space," according to writer Sharon Dunham. "The goal is to develop environmentally friendly methods for space travel that are not harmful to humans," she wrote. "This will be the first biological control experiment in space."
She went on to relate that experiment will "test the movement and infection behavior of beneficial nematodes (also called entomopathogenic nematodes or EPNs) that control a wide array of insect pests in agriculture." ARS research entomologist, David Shapiro-Ilan at the Fruit and Tree Nut Research Station in Byron, Ga., is co-project director of the experiment.
Nematodes, Dunham said, are "environmentally friendly alternatives to broad spectrum chemical insecticides and are also safe to humans and other nontarget organisms. One fascinating aspect of the EPN biology is that the nematodes kill their insect pest hosts with the aid of symbiotic bacteria that are carried in the nematode gut."
Nathan Augustus Cobb (1859-1932), the "father of nematology in the United States," had this to say about a world without nematodes.
"In short, if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable, and if, as disembodied spirits, we could then investigate it, we should find its mountains, hills, vales, rivers, lakes, and oceans represented by a film of nematodes. The location of towns would be decipherable, since for every massing of human beings, there would be a corresponding massing of certain nematodes. Trees would still stand in ghostly rows representing our streets and highways. The location of the various plants and animals would still be decipherable, and, had we sufficient knowledge, in many cases even their species could be determined by an examination of their erstwhile nematode parasites."
In fact, nematodes seem totally destructible.