prairies - Prairie Rivers of Iowa

Tallgrass Prairie – A View from the Fly on the Gall

by Jessica Butters | Jul 13, 2023

The North American Prairie Conference was a big conference (638 people from 24 states and 2 countries) but not all the sessions dealt with big mammals, tall grasses, and wide open spaces. During a break from working the registration table, I caught some delightful talks by MJ Hatfield and Chris Helzer about the tiny creatures you can meet and the stories you can learn if you “walk slow, look close, and be curious” – MJ Hatfield.

Howdy! I’m a goldenrod gall fly (formally, Eurosta solidaginis). Have you ever seen flower stems with an odd, ball-shaped growth? These round growths are called galls, and if you’ve seen one on goldenrod, I may have been the architect that created it. But what exactly is a gall? To me, a gall is a highly specific and comfy nursery, created with a little hijacking (picture to the left © MJ Hatfield).

A gall can be about anywhere on a plant, including flowers and leaves, and are created by hijacking the plant’s hormones. You read that right. I’m a hormone hijacker. In spring, before I was born, my mother inserted her egg (me!) into the goldenrod’s stem. Later, when I hatched into a larva inside the goldenrod, I started eating the inside of the stem. My saliva contains chemicals that trick the plant into thinking the saliva is its own hormones. My saliva signals the goldenrod to grow more tissue in the feeding area (or nursery, as I like to call it). The goldenrod ends up creating a beautiful, round nursery. In short, I’ve built my very own gall. I’ll eat and grow in this goldenrod gall throughout the summer until fall. In autumn, I chew a tunnel near the outside of the gall and then pupate, waiting until spring to emerge. But how the heck am I supposed to get out of the gall?!

This is where it gets seriously interesting. I have an air bag like structure on my head between my eyes. I inflate this air bag against the gall, and bam! I break through, seeing the outside world for the first time. Also, this whole process doesn’t hurt the goldenrod. It nearly always flowers like normal and continues enjoying life as a goldenrod plant.

My species can’t survive in any other plant. Because I’m a weak flier, I will probably stay in the same neighborhood that I grew up in. I hope nothing happens to this patch of goldenrod…I’m not sure if I could make it to a different prairie patch. Maybe if there were more prairie plantings, it wouldn’t be so drastic if changes came to my neighborhood. The prairie restorations could act as a safety net.

Goldenrod gall with gall fly, by MJ Hatfield

As the goldenrod gall fly, my entire life and future requires the presence of goldenrod. And I’m not the only one! At least two moth species also make galls on goldenrod. There are quite a few bees that rely solely on goldenrod pollen. You might think we are picky, but can you imagine how hard it is to find a home that you can not only live in, but also eat? And us gall flies have to develop specific chemicals in order to hijack specific plant hormones to even make our home and food. It’s very complicated, and we can’t just change all that with a snap of our wings!

Stiff leaf goldenrod, photo credit Dan Haug

Many people now know that monarch caterpillars can only eat milkweed, and are planting gardens with milkweed to help them. That’s great, but monarch butterflies are not the only insect that needs a certain plant for food or shelter. Sawtooth sunflower has four different species of gall-forming insects that dependent upon it. The blue sage bee requires pollen it can only get from blue sage flowers. Swallowtail butterflies rely on plants in the carrot family (such as golden alexander). Make room for a diverse prairie planting and you could be supporting ten times as many species of insects, many of them so small or well-camouflaged that few people have ever met them!

Tallgrass Prairie – A Butterfly’s View

by Dan Haug | Jul 13, 2023

The tallgrass prairie once covered 170 million acres, and at the 2023 North American Prairie Conference, I was reminded of that continental scale. Between assisting presenters with technology, I heard sessions about protecting orchids in the aspen-prairie parkland of Manitoba, time lapse photography along the Platte River in Nebraska, surveying insects in Alabama’s “Black Belt”, restoring spring wildflowers on the Kankakee Sands of Indiana, and building out the native seed supply chain in South Dakota, as well as lots of good information from friends and colleagues in Iowa. The following are a few insights I picked up from the conference, written from a butterfly’s perspective.

Hi, I’m a monarch butterfly (Danaus plexippus). Like the meadowlark, I continued to thrive in Iowa long after the prairie was broken. For me, the tipping point was when GMO soybeans and copious use of herbicides replaced “walking the beans” as a method for weed control. No more milkweed in farm fields! Like the meadowlark, I’m a strong flier and not too picky about my habitat, but I’ve got two pairs of eyes (two compound eyes and two ocelli) so my perspective is a little different!

Monarchs on meadow blazingstar, photo credit Monarch Butterfly Garden

For me, it’s all about the forbs—broad-leaved herbaceous plants. I know, you can’t have grassland without grasses, but I need milkweeds to feed my caterpillars and nectar-producing flowers to drink. I’m visit whatever flowers are blooming (I’ll even use non-native forage plants like red clover and weeds like musk thistle) but since Dr. Benedict and his students are asking, yes, I do have some favorites. In addition to milkweeds, I’m partial to plants in the sunflower family, which have heads packed with nectar-producing, short tubed flowers that make for easy sipping. At the Central College prairie, compassplant (Silphium laciniatum) is my top choice, but that’s just because you don’t have any meadow blazing star (Liatris ligulostylis). As native plant nurseries and seed producers can attest, we monarchs go nuts for that!

In some remnant prairies, we’ve seen the forbs get crowded out by aggressive grasses like big bluestem and switchgrass. It’s even worse in restored prairies that used too much grass in the seed mix—we see this with older CRP plantings. On the other hand, a seed mix without any native grasses won’t have all the functions of a prairie and won’t hold up well against invasive weeds. In an intact prairie, the big warm-season grasses are important, but they’re kept in check by a combination of fire and grazing—the fire makes the grass green up and then the bison chow down! Hemiparasitic plants like lousewort (Pedicularis lanceolata) and bastard toadflax (Commandra umbellata) also set back the grass by sending a modified root into the grass roots and sucking out their juices. Prairie isn’t just a collection of native plants, it’s a web of relationships!

Few reconstructed prairies have bison or hemiparasitic plants, so check out this NRCS publication for other ideas to increase forb diversity in grass-dominated stands.

If you’re starting from scratch, be sure to use a seed mix like CP25 or CP42 that includes plenty of native flowers. We’re happy to learn that over 600,000 acres in the Conservation Reserve Program (CRP) have been planted with these mixes.

Iowa can be an inhospitable place for an insect, but thanks in large part to the efforts of the Tallgrass Prairie Center at UNI and the Iowa DOT’s Living Roadway Trust Fund, we have a better supply of native seeds than many other states, and many miles of roadside ditches planted to prairie. Next step, find some more room for prairie plantings on farms and in cities!

NAPC field trip to Neil Smith Wildlife Refuge

This article is based on sessions presented by Laura Jackson (University of Northern Iowa), Tom Rosburg (Drake University), Russell Benedict (Central College), Justin Meissen (University of Northern Iowa), Brian Wilsey (Iowa State University), and James Cronin (USDA-NRCS).

Tallgrass Prairie – A Bird’s Eye View

by Dan Haug | Jul 13, 2023

The tallgrass prairie once covered 170 million acres, and at the 2023 North American Prairie Conference, I was reminded of that continental scale. Between assisting presenters with technology, I heard sessions about protecting orchids in the aspen-prairie parkland of Manitoba, time lapse photography along the Platte River in Nebraska, beetles in the prairies of Alabama’s “Black Belt”, restoring spring wildflowers on the Kankakee Sands of Indiana, and building out the native seed supply chain in South Dakota, as well as lots of good information from friends and colleagues in Iowa. The following are a few insights I picked up from the conference, written from a bird’s perspective.

Hi, I’m an eastern meadowlark (Sturnella magna). I grew up in the tallgrass prairie, but I’m not picky about the species composition of my grassland habitat. I was the most common bird in Iowa for a century after the prairie sod was broken, making a good living in hayfields and hedgerows. Things didn’t get really bad for me until the second half of the twentieth century, when most Iowa farms dropped alfalfa, hay and small grains in favor of corn and soybean production at ever larger scales. That conversion is also the root of the nitrate problems in Iowa’s rivers.

But the flip side of that is that grassland generalists like me don’t need a perfectly authentic prairie to make a comeback. A food system that included more pasture and forage crops to raise animals could make a big difference for wildlife, water, and the vitality of rural communities.

For more on this concept, see the University of Wisconsin’s “Grassland 2.0” project, which is reimagining a food system that provides the ecological functions of prairie. The new book “Tending Iowa’s Land” edited by Connie Mutel comes to the same conclusion: the book introduces Iowa’s four worst environmental crises with a combination of science and stories, explains their historical roots, and outlining visions for a more sustainable future. Laura Jackson’s presentation also provided inspiration for this article.