Courtesy of http://www.poweshiekskipper.org/forecasts.htm
April 16-30, 2009
We have had a number of days in the first part of April
that are almost but not quite good butterfly days. Highs were in
the upper 50's and it was sunny at least some of those days.
Another 10 or 15 degrees and we will be seeing lots of butterflies.
I saw a cabbage white on Tuesday, the 14th, in Red Oak. Chris Edwards posted that he had seen a Cabbage white on the 15th. In addition, a number of butterflies--mostly those that over-winter as adults--have been seen and reported on the Wisconsin Butterflies site (see below) and others.
All of the butterflies predicted as possible for the early part of April can also be found in the latter part of April. Mourning Cloaks, comma and question mark butterflies which have over-wintered as adults are possible.
Common butterflies that over-winter as larvae or pupa, such as the cabbage white, spring azure, and black swallowtail should start to be present in fairly good numbers.
Butterflies that migrate, such as the red admiral (shown here on the right), the painted lady, buckeye, American lady, and monarch can show up during this time period as well. Large numbers of red admirals or painted ladies can suddenly show up after a thunderstorm. Look at them closely, and you will usually see that they are fairly beat up, indicating that they emerged as adults some time ago and have followed the prevailing winds to get here.
There
are a number of rare butterflies you can look for during this time
period as well. The Olympia marble is well documented from the
northeast and western part of Iowa. It may occur in central Iowa
and has been reported in the Ledges State Park area and in Ames, but
needs to be documented for those locations.
I have seen juniper hairstreaks, like the one shown on the left in two of the nine years I have lived in rural Dallas County. One year I saw a number of them on a large cedar tree along a fencerow. I have looked for them extensively since with no real luck. Juniper hairstreaks are well documented on the edges of this state but not so much in the central part. I suspect they are more common than they appear but they are difficult to find.
Another rare hairstreak is Henry's elfin. It is found in the southern part of the state, where its larva feed on redbud and the adults are found nectaring near the larval host. I have tried for a number of years to see this butterfly, but so far I have been unsuccessful. Brown elfin, eastern pine elfin, and hoary elfin may also be possible for Iowa, but so far they have not been documented. All three are found in areas near Iowa, and have a short, early flight period. All are extremely restricted in habitat, some of which might be present in small areas of northeast Iowa. Look for these species in late April and early May. Good information about these species can be found at http://www.wisconsinbutterflies.org.
Happy butterflying.