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Upcoming Events

For Lands Sake! and Winterset Library One Earth Book Club:

Tuesday, Jan. 23: “Sylven T. Runkel: Citizen of the Natural World” — Stone and Stravers

Meet at 7:00 PM at Winterset Library

 

Decatur County Christmas Bird Count: Saturday, Dec. 16. Meet at 7:30 a.m. at the Kum and Go near the Iowa visitor center.

 

Next SIOSA board meeting

Thursday, December 14, 1:00 PM at Decatur County Conservation Board office west of Leon, 20401 River Road.

Field Journal September 15-30

Tuesday, October 3, 2017 @ 02:10 PM
posted by veronica

By Sibylla Brown, Timberhill Oak Savanna

So far fall is making up for a very disappointing summer Lepidoptera season.  In the last two weeks several Underwing and Stem Borer moth species were attracted to our black-light fluorescent tubes.  We alternated one light between the Hickory Grove and West Creek prairie remnant, the other in front of a sheet strung between two poles in the East Savanna. The East Savanna site is on top of a ridge of widely spaced oak trees over an understory of native forbs and grasses. 

Catocala neogama

 

Near the Hickory Grove I was particularly pleased to collect Catocala neogama, The Bride. This species has yellowish-orange underwings with black bands that are very similar to Catocala subnata, Youthful Underwing. To tell the difference, one must inspect the hind legs:  in C. neogama the tibia is flattened and very sparsely spined whereas it is cynlindrical with dense uniform spines in C. subnata.

A few years ago a friend introduced me to Stem Borer (Papaipema) moths.  At the time I only looked for Stem Borer species long enough to determine that they were to be found at Timberhill. Since then I’ve been too focused on surveying the Catocala to look at other genera.  Last week when my friend asked what Stem Borers had come to our lights I was ashamed to admit that I hadn’t even thought of looking for them this year. But we began looking for them last week.

Indigo Stem Borer

 

Papaipema, Stem Borers, are medium-sized moths which are often brightly marked yellow or orange with white spots on the forewing. There are also essentially unmarked dark forms with only a faint outline of spots. Moths of this exclusively North American genus emerge in late summer and fall when they deposit eggs on or near their larval food plant.  The eggs overwinter in the leaf duff and hatch in May.  After hatching, the larvae tunnel downward into the stalk and roots where they mature.  Since most are food plant specialists that require very specific habitats, a number of them are nearing extinction. (Wagner)

Cream Wild Indigo blooming in the East Savanna

 

Both Cream and White Wild Indigo are abundant at Timberhill and we have collected more Indigo Stem Borers than any other species. Cream Wild Indigo which blooms in early May is well established under the widely spaced oak trees in the East Savanna.  In summer White Wild Indigo blooms in all our prairie remnants.  So I was not surprised to see the Indigo Stem Borer on September 28.  Two more came to our lights on September 30. We also attracted some dark species which were too worn to identify.  I’m already looking forward to next year when I will begin looking for Stem Borers on September 1.    

David L. Wagner, Dale F. Schweitzer, J. Bolling Sullivan & Richard C. Reardon.  2011.  Princeton University Press.  Princeton

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