I am Sibylla Brown. I was born in Germany in 1940. In 1946 my father, a German Operation Overcast scientist, was brought to the U.S. My family followed him to the U.S. in 1947, settling in Cedar Rapids Iowa in 1950. I married my husband, Bill in 1962. Bill practiced dentistry in Des Moines for over 40 years. In 1993 we sold our house in Des Moines and moved to a 200 acre farm in Decatur County, Iowa. Except for a small vineyard we had no plans to farm our land. But we did want to take care of it, particularly the overgrown oak and hickory woodlands. We began timber stand improvement in 1993. When we learned our land was actually a rare oak savanna remnant we implemented prescribed fire. These posts share how we found the land and how we made the transition from city-dwellers to country folk.
The best moth collecting usually coincides with the dark of the moon. Fortunately we had a few nights shortly after the new moon June 16 when rain did not threaten and we could set up our moth lighting in the East Savanna and on adjacent unmanaged property. On the adjacent property we used a moth trap constructed at the local welding shop. It consists of a funnel in a hardware cloth cage with a removable bottom. A black light fluorescent tube is suspended from a plant hanger attached to hoops on top of the cage Moths attracted to the black light fall through the funnel into the cage. they usually perch to the sides of the cage. The next morning we list and inventory the specimens. The specimens are then released.
The site most similar to conditions in the East Savanna is a wide opening in the oak and hickory woodland south of our property line. The first night the trap filled with geometer and three blinded sphinx moths. The second night there was more diversity, In addition to the geometer moths we collected two Luna moths, a Little virgin tiger moth (county record), 3 yellow underwings, a Small eyed sphinx (2014 county record), an Io moth (2014 county record), 2 more Blinded sphinx (county record), and one Giant leopard moth (2014 county record).
We collected the same species in East Savanna. In addition a luna moth, a twin spotted sphinx, two Imperial moths, several Isabella tiger moths, and a polyphemus moth were also attracted to that black light. And there was much more diversity with many small specimens that I did not identify.
Two species are of particular note: the Io and Imperial moths. In 2014 the Io moths I collected were the only collections of that species submitted to the Insects of Iowa website. So far this year we have attracted four specimens at Timberhill. This is a habitat sensitive species since the cocoons overwinter in leaf duff, under dry logs, or on hickory leaves. Finding them here indicates that the cocoons survive our annual dormant season prescribed burns.
The Imperial moth is another species in decline. Although it used to be common throughout its historical North American range it is in decline throughout the northeastern US. In 2014 the Insects of Iowa site listed only four sightings, two of which were in Decatur County (Lamoni and Timberhill). Imperial moth cocoons overwinter in underground burrows.
We will need to accumulate much more collection data to determine how our woodland management is impacting moth diversity. But the fact that we are finding rare habitat sensitive species at Timberhill is a good sign.
Michael M. Collins and Robert D. Weast. 1961. Wild Silk Moths of the United States. Cedar Rapids, IA: Collins Radio Company
(This growing season Bill and I are documenting as many breeding resident butterflies and moths as we can find and identify. In order to assess how our prescribed burns impact the Lepidoptera we are comparing our Timberhill collections to what we find on adjacent unburned woodland, wetland, and meadows. This will not be a list of all the species we see. Rather, we will focus on habitat sensitive species that spend their entire life cycle here. Neither of us is an expert lepidopterist but we hope to learn by doing. We identify our specimens by referencing various field guides and websites such as Insects of Iowa.)
Moth collecting centers on the use of lights. Although moths are attracted to existing lights on our buildings’ exteriors we chose to use portable lights that we can place closer to larval food sources. Our set up is supported by two poles that Bill had purchased to hang hummingbird feeders. At the chosen collecting site Bill inserts a screwdriver into a hole in the base of each pole, turns it, and screws the pole into the ground. A white sheet hanging from a clothesline strung between the poles is illuminated by two AC/DC fluorescent black light tubes which emit not only visible light but also the shorter ultra violet light that attracts moths. We power the lights with a portable rechargeable battery. We turn the lights on at dusk and monitor the sheet several times during the night, usually two hours after dusk, at 3:00 AM, and again just before dawn.
Spring is such a busy time that we didn’t begin our moth collecting until late May. We set up the light in East Savanna ridgetop. Surrounded by oak and hickory woodland this site is where we began our restoration and is our most diverse savanna with abundant stands of leadplant, cream wild indigo, and blazing star. Our first night was cool and when I checked the sheet at 10:30 PM all I saw were some beetles. But in the middle of the night numerous moths had settled on the sheet. Most interesting were a Blinded sphinx (Paonias excaecata) and a specimen I couldn’t identify. It was very distinctive: black speckled gray forewings with two white cell spots and rose colored hindwings. I assumed it was a owlet because it held its wings rooflike at rest. When I realized that I was stumped I guessed that I must have overlooked something really obvious. I had. I had neglected to check for a proboscis, the long thin moth feeding tube. (Silk moths don’t have proboscides because they don’t feed.) I sent a photo of my specimen to an expert friend who easily identified it as the common Honey locust moth (Sphingicampa bicolor).
On the other hand I’m not surprised that I couldn’t identify this species. Coloration is highly variable; early broods are gray, later broods are reddish brown to reddish orange. It may or may not have white cell spots on the forewing and the wings may or may not have scattered black specks. And most important we don’t have any Kentucky coffee or honey locust trees, of its primary larval food sources.
Both species spend their entire life cycles here overwintering in the ground as pupae. And both are Decatur County records.
(This growing season Bill and I are documenting as many breeding resident butterflies and moths as we can find and identify. In order to assess how our prescribed burn impacts the Lepidoptera we are comparing the Timberhill collections to what we find on adjacent unburned woodland, wetland, and meadows. This will not be a list of all the species we see. It will be our observations of habitat sensitive species that spend their entire life cycle here. Neither of us is an expert lepidopterist but we hope to learn by doing. We identify our specimens by referencing various field guides and websites such as Insects of Iowa.)
The Timberhill butterfly season began on March 30, a sunny and breezy day with the thermometer reaching 72’ F. , when Bill and I saw a mourning cloak, a breeding resident that overwinters as an adult. He flew out of the managed woodland east of the trail as we walked south through Butterfly Alley, the trail that separates our southeast woodland from the neighbor’s unmanaged woodland. Broad and sunny, Butterfly Alley is always a good spot for butterflies, especially in early spring.
Our next sighting was on April 11, another warm and sunny day with 73’F. Pairs of spring azures flew overheard while single specimens settled on the rue anemone and spring beauty blooming east of the trail. Near a clump of gooseberry bushes bordering the unmanaged woodland we saw a gray comma. Another breeding resident this species also overwinters as an adult. I saw another specimen in the Timberhill south meadow the following day.
It was April 29 before we saw the first skipper – a Silver spotted skipper on the south portion of the trail with unmanaged woodland on both sides. As we walked north we saw a Juvenal’s duskywing perched on a dead plant stalk at the edge of the unmanaged woodland. Juvenal’s is an uncommon breeding resident of open oak woodlands and adjacent areas. (Oak is its larval food source.) Further north was a Common sooty wing, a common breeding resident.
The rest of the week we moved our butterfly search to Timberhill. We had seen silver spotted skippers there but would we find any Juvenal’s duskywings? We began our search in the prairie just south of the Hickory Grove. Like all of our prairie openings it is surrounded by mixed oak-hickory woodlands. On May 6 we saw four Juvenals and one Silver spotted skipper in this prairie remnant. Despite intermittent rain and strong wind gusts we saw two Juvenal’s and two silver spotted skippers in the east savanna ridgetop oak opening on May 7. We found a similar pattern in the Hidden Prairie where we saw four Juvenal’s and one Silver spotted skipper on May 8.
Our last sighting of the Juvenal’s skippers was on May 13 in the East Savanna ridge top. Bill noticed movement among the scrub oak in the center of the oak opening. Carefully Bill stalked and netted one of the specimens so we could identify the species. Instead of one specimen we found two Juvenals in the net. When we released them one settled on an oak leaf in front of us and the other flew swiftly away. A mating pair? Was she was laying her eggs in the scrub?
As we headed back to the house a giant swallowtail flew swiftly overhead. The summer season is about to begin.
Brock, Jim P. and Kenn Kaufman, Butterflies of North America.
Schlicht, Dennis W., John C. Downey, and Jeffrey C. Nekola, The Butterflies of Iowa.
In January 2009 there was a discussion on this list serve of the decline of habitat dependent invertebrates on Iowa prairies. Dennis Schlicht’s s “Prairie Paradigms “ paper* was specifically noted. I disagreed with paradigm 5 that “invertebrates that reside in any life stage above the ground do not survive dormant season fire.” Although we use annual dormant season fire to manage our restoration we have not found this to be true of ants, native bees, or beetles. Lists of these invertebrates that were compiled here by experts include not only habitat dependent species but several Decatur County records as well.
In that discussion I was strongly criticized after I wrote a post expressing the belief that annual dormant season fire leaves much invertebrate habitat because the fire is always going upward, “burning the fine standing fuels of the season.” In annual burns the fire leaves a patchwork of burned, partially burned, and unburned ground. These burns are much less destructive to habitat specialist invertebrates than occasional burns.
It didn’t take long for someone to respond that that “insects, eggs, or immature stages within the plants and the thatch cannot survive such a burn regimen.” My chief critic then asked me, “What skipper species were there before you started burning? Are they still there? You are conducting a scientific experiment-burning an ecosystem which has been unburned for years-without a control.”
I am not a scientist nor are Bill and I conducting a scientific experiment at Timberhill. We are simply landowners who have learned that fire is the most effective means of restoring the overgrown woodlands, prairie openings and wetlands on our 200 acre property. Ever since that discussion, however, I knew that I would have to document the Timberhill Lepidoptera and determine how our fire regimen impacts them.
That is easier said than done. In 2009 I could recognize the common butterfly species but knew nothing about skippers and other habitat dependent species. Thanks to the kindness of a couple experts I have since learned to identify more species. And there are numerous Internet resources such as the Insects of Iowa website and the Iowa Insects list serve when I need help with identification. I have also found two lists of Decatur County butterflies. So during 2015 growing season Bill and I plan to identify as many Timberhill Lepidoptera as possible. And we have permission from a neighbor who has neither burned nor thinned his woodland and prairie to look for butterflies on his property.
One of our favorite butterfly spots is a trail we call butterfly alley. It is where we always see the first mourning cloak of the season, where spring azures flit through the spring ephemerals and tiger and giant swallowtails glide among the treetops. The trail separates our southeast woodland from the unmanaged adjacent property. The two photos above demonstrate the difference in ground cover ephemerals between the burned and unburned woodland. This is where we will begin our survey.
*Dennis Schlicht, Iowa Lepidoptera Project, 1108 First Ave. Center Point, IA 52213 (First Presented in public lecture in Iowa City, IA on October 3 1993
April is birthday month at Timberhill. Our son Alex and I were both born in April. It has become our custom to combine our celebrations on the same day. This year our celebration coincided with the beginning of the morel mushroom season.
A choice edible these fungi have a limited season, fruiting for only a few weeks in April and May. From early April I watch for the signs that morel season is about to begin. I listen for the constant singing of the tree frogs, watch for the first asparagus spears in the vegetable garden, for the leaves of the silver maple trees to emerge, and the mayapple leaves to open. When the woodlands are fully carpeted with spring beauty, trout lilies, toothwort, and other spring ephemerals I know the time is near.
We never know where the first morels will fruit. Will we find them under the dead cottonwood in our West Creek unit? Or under the silver maple and elms along Brush Creek? In 2011 we harvested early morels in the hickory grove west of our house. Last year we also found them associated with river birch in the West 40. The only sure thing about morels is that they always surprise us.
On April 16 Bill and I found the first specimens fruiting in a patch of mayapples in the hickory grove. But we waited until April 18, the day of our birthday celebration to harvest them. Our sons Chris and Alex were both here. After a breakfast of fruit compote and asparagus and mushroom frittata we walked to the hickory grove and harvested twelve yellow morels fruiting there. (After the first morels appear it usually takes another week for the main crop to fruit.)
We began our birthday celebration dinner with a fresh asparagus appetizer and Champagne J. Lasalle. For the main course I combined the fresh morels with reconstituted dried morels (from last year’s harvest) in a pan sauce for veal chops. We served the the veal chops smothered with morels and pommes de terre macaire. To accompany our spring feast Bill poured a bottle of Saint-Romain Cote d’Or burgundy wine.