Loess Hills Restoration Newsletter

Volume 2, Issue 1

Text Box: Regal Fritillary—Speyeria idalia The Regal Fritillary butterfly is one of many imperiled prairie species. It was originally found all across the United States and is now extinct in 40% of it’s range. Today it is found only in the Midwest, in a few fragmented populations. According to the USGS Northern Prairie Wildlife Research Center, the Regal Fritillary in Iowa is “rapidly vanishing or declining in much of its range.” The decline is due to disappearing remnant prairie and a lack of habitat management. The Regal Fritillary caterpillars feed specifically on native violets in tallgrass prairie. The caterpillars hatch just as the violets begin to grow in early Spring. The caterpillar is black with orange and yellow stripes and spots, and branching spiny hairs. Butterflies emerge and fly from June until August.

Text Box: Prairie Violet—Viola pedatifida The Prairie Violet, preferred Fritillary forage, can be considered an indicator of a high-quality prairie remnant. Prairie Violets can be found in the remnant prairies and oak savannas of the Loess hills. The flowers resemble that of the Common Blue Violet although the leaves are deeply lobed. “Pedatifida” means “deeply clefted”. The Prairie Violet is also referred to as the Crowfoot or Larkspur Violet. “Crowfoot” is in reference to the leaves’ bird-foot-like shape. Prairie Violet is a perennial, typically five or six inches tall. It blooms from April to June. Seed is formed in small, petal-less flowers formed underground. Prairie Violets require habitat management due to their shade–intolerance and require burning or tree and brush removal to keep the overstory open. Early spring or late fall burns are the most beneficial to remove litter and promote seedling establishment.

Text Box: availability of formulations approved for use in wetlands (such as Rodeo® or Aquaneat®). Picloram (e.g. Tordon®, Grazon®, etc.) is a systemic, water-soluble, broad-spectrum herbicide. Picloram is persistent and mobile in the soil, presenting issues with ground-water contamination. Most grasses are resistant to Picloram, although it’s persistency in the soil may cause non-target kill on native forbs. Triclopyr (e.g. Garlon 3A®, Pathfinder II®, etc.) is a non-water-soluble, systemic, selective herbicide. Triclopyr requires a surfactant such as diesel fuel or a commercial bark oil diluent (e.g. Bark Oil Blue®). Bark oil is recommended as diesel fuel can damage adjacent vegetation. Because it is oil-based, it will not freeze, making it effective even in winter. Triclopyr is also the most selective of the three herbicides, having almost no impact on native grasses. Always apply herbicides according to label directions.

Text Box: Tree and brush removal is often a requirement of any prairie restoration. When trees are cut down, chemical treatment is recommended to prevent the stump from re-sprouting. This is commonly referred to as ‘cut-stump treatment’. Fortunately for the prairie restoration world, cedars will not re-sprout if they are cut below any green growth. Unfortunately, deciduous trees will. Cut-stump treatment consists of applying herbicide to the top of the stump around the cambium (see inset). Herbicide can be sprayed on with a low-pressure sprayer or applied with a sponge-type paint applicator. Dye can be added to the herbicide to keep track of stumps already treated. Several chemicals are available for cut-stump treatment, three of the most common include the glyphosate, picloram and triclopyr. One consideration in choosing an herbicide is the side-effects on desirable vegetation, such as in a remnant prairie. Glyphosate (trade name Roundup®, Rodeo®, etc.) is a systemic, water-soluble, broad-spectrum herbicide. It is not recommended for use in quality native vegetation to avoid non-target kill. An advantage of glyphosate for cut-stump treatment is the

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