HomeOarisma PoweshiekThe History of the ButterflyIowa's Biological Diversity  
The Poweshiek Skipper Project
 
Butterfly Forecasts for Central Iowa  
  Mid-September 2020 to End of Season  
  SachemThe end of the summer of 2020 hit me with a bout of illness and a computer crash.  I am slowly recovering from both, so please bear with me.  I feel like I've stumbled and fallen out a race, but am determined to finish anyway.
For all of its other issues, this year was a pretty good year for butterflies.  There were good numbers, and there were some rare sightings by several individuals.  There were also challenges for butterfly watching.  Some public areas had restrictions due to the Covid-19 virus.  Other areas had such high density of human visitors that it became prudent to self-restrict visits to those areas.  Then there were the nature events that either were cancelled or were never scheduled because of the virus.
There were some recent sightings of pretty good numbers of monarchs, congregating on their southward journey.  The bulk of the monarchs have probably left the state by now, but we should still see some of the stragglers.  Warm, sunny days will still have pretty good numbers of butterflies, at least until we get our first light frost.  Then the numbers and diversity will go down rapidly.
Eastern tailed-blues are still out.  Orange and clouded sulfurs are still flying.  In my experience, the orange sulfur flights seem to end with the first frost, but the clouded sulfurs hang on until there is a killing frost.  Cabbage whites are flying now, and will persist for a while. Black swallowtails, giant swallowtails, and eastern tiger swallowtails often persist until the last week of September or later, but I would not be too hopeful on seeing them after the extended rains that we had.  We might still see them, however.Silver-spotted skipper
While most of Iowa's butterflies do not have a two-way migration, there are a handful that do.  The monarch is the most visible because it forms large clusters.  In addition, painted ladies, American ladies, red admirals, and buckeyes are known to migrate.  You might see good numbers of those species over the next few weeks. Others just live out the rest of their short lives mating and laying eggs while the conditions allow.  Pearl crescents, meadow fritillaries, viceroys, and red-spotted purples are among the species that might be seen late in the season.  Several skippers become pretty common towards the end of the summer and start of autumn, including some that are not normally seen until then.  Fiery skipper, sachem, common checkered skipper, and tawny-edged skipper are among that group.
If you happen to live near an apple tree, and if you leave the fallen apples alone, the slightly rotten apples become a bait station for all kinds of insects, including butterflies.  Look for some of the previously mentioned species, plus question marks and eastern commas.  The apples will also attract wasps and hornets, but they are not too defensive in this condition and can be approached safely.
The butterfly season is tied to the weather.  Some years butterflies are gone by mid-October.  Some years they persist until the end of November.  Enjoy them while you can.  Let's hope for a short and non-eventful winter, and soon we will be enjoying butterflies again next spring.

Until then....

Harlan Ratcliff
 
  Great Spangled fritillary  
  August 2020  
  Dainty sulfurTime moves on.  August is a great time for butterflies, but the summer is sliding past.  Already the days are getting shorter.  If you have a chance to visit a good prairie, do so.  The flowers are at their peak right now.
The diversity and population sizes of butterflies are high right now.  The butterflies that have multiple generations each season can be especially numerous.  Orange sulfurs and clouded sulfurs are very common and can be easily seen.  Cabbage whites are frequent visitors to back yards and gardens.
If your eyes are tuned to them, you can see a small flash of silver/blue from thirty feet or more.  Eastern tailed-blues are about an inch or less long.  I have run into people who see them for the first time and are surprised that such a butterfly exists.  Yet they are probably the most common butterfly around at times. When you walk in an area with only turf grass and no flowers you might not be aware that there are any butterflies around.  But once you learn to look for them you will see them everywhere. 
Summer azures should still be around in smaller numbers late into the month.  Most of the hairstreaks are gone for the season, but gray hairstreaks often become more and more common late in the season and should be seen on a regular basis.  In wetland areas particularly you might also run across bronze coppers.
Depending on where you look for butterflies, you might never run across a dainty sulfur.  But if you find a habitat where they are, they are likely to be very common.  Some areas of Saylorville reservoir that flood when the water is high end up being very good habitat for this butterfly.  Look for them around boating access areas.  If you walk around the weedy areas where they are found, however, you are likely to come across cockle burrs, which may be a host plant for this little gem.
One of the few annual prairie plants we have here in Iowa is partridge pea.  If you find a large area of partridge pea, you will also likely find little yellow in pretty good numbers.  In August it is also possible to run across cloudless sulfurs and sleepy orange.  Both also use partridge pea as a host plant, and can be very common in areas south of here.  We are usually lucky to see a few individuals, however.
Swallowtails continue throughout August.  The big three for central Iowa are the black swallowtail, eastern tiger swallowtail, and the giant swallowtail.  You should be able to find some old, battered individuals and some fresh new ones, often at the same time.
Great spangled fritillaries can often be seen in August, but are often quite worn and battered by then.  You may see some that have less than half of their original wing surface area, but they still persist.  Painted ladies, red admirals, and buckeyes can be seem pretty fresh though.
little yellowRed-spotted purples (officially called red-spotted admirals now) and viceroys have pretty good flights well into August.  Apparently a local common name for the red-spotted purple (which you won't find in books) is black and blue monarchs.  Some old geezers around here still use that term.
 Pearl crescents and silvery checkerspots persist throughout the month.  Gorgone checkerspot are considerably more rare but you might see them in prairie areas.
Of course, monarchs will be building up numbers as well.
As the season goes on, certain skippers can really build up their numbers.  Watch for fiery skippers and sachems to become common.  They typically are not seen in high numbers earlier in the year, but cannot be missed late.  You will also likely see large numbers of tawny-edged, Peck's, least, and common checkered skippers.  Silver-spotted skippers will be hanging around the tall and bull thistles, along with other large butterflies.
While it is not a butterfly, there have been several sightings of a rare treat this summer--the black witch.  This large moth really impresses with its size.  If you are lucky enough to see one in flight, it looks all the world like a bat.
This year has been especially frustrating for me and I think for most people I know as well.  I have been able to get out with my camera some, but for a number of reasons I have not been out as much as I would like.  Butterflies do not cure the world's ills, but they sure seem to boost my mental health.  And this year seems to be a good year for them.  I would encourage all of you to get out as much as you can before the season is over and enjoy these little gems of color.

Harlan Ratcliff
 
  Great spangled fritillary  
  July, 2020  
  Regal fritillaryJuly is a great time to see butterflies in Iowa, both in terms of diversity and of overall numbers.  I have been able to get out some, but not as often or for as long as I would like.  Still, some of the butterfly experiences I have had recently recently have been borderline magical.  From the posts I have seen on the Iowa insect list serve, the Iowa butterflies facebook site, and Jim Durbin's Insects of Iowa database, other people have been seeing some special butterflies as well.
Let's start with the Regal fritillary.  This is one of Iowa's largest butterflies--about the size of the well known monarch.  It is usually only found on good prairies--I posted a short list last month and won't repeat it here.  When they are present they are fairly easy to find, but they are pretty restless and fly good distances, making it very difficult to get a good photograph.  I headed down to Warren County early on a Saturday, thinking I had made a mistake because it was raining.  I saw and photographed a number of butterflies most of the morning, including regals flying in the distance. But when I stopped at the small gravel parking lot at Rolling Thunder prairie, there was a small puddle of water, and two regal fritillaries were drinking from the mud there.  I was able to crawl on the gravel and get within about a foot to take a number of photos.  I had an issue with the flash on my camera--I got some good pictures, but not quite as good as I had hoped.  Still, it was a magical experience.  I am in awe of Regal Fritillaries. There have been recent reports of regals seen in Polk, Plymouth, and Decatur Counties so this seems to be a good year for them.
Another large butterfly that seems to be having a good year is the zebra swallowtail.  These butterflies can be reliably found only in Lee County on the southeast corner of the state, and in Fremont County on the southwest corner.  This year there have been sighted several times near Des Moines and near North Liberty as well.  Watch for them.
The more common swallowtails in this area are black swallowtail, eastern tiger swallowtail, and giant swallowtail.  They should all be present and highly visible this time of year. 
Several butterflies have only one generation per year, and are present as adults for only a few weeks in the summer.  Many of them can be found now.  Baltimore checkerspots are one such butterfly, and they are extremely limited in habitat as well.  In Iowa they are only found in a special type of wetland called a fen.  They are quite rare in this state, but Chris Edwards and Tom Schilke reported finding over 50 of them in the Volga River State Recreation Area in north eastern Iowa.  They should be out now and for a few more weeks.  The Nelson Paradise Wildlife area, near Minnesota might be a good place to look for them as well
There are several species of hairstreaks that are flying now.  I have seen a couple of photos of striped hairstreaks posted recently.  Good luck finding one of them!  Edwards hairstreaks are a little more common but still pretty rare.  You should be able to find banded hairstreaks and coral hairstreaks.  Common milkweed and butterfly milkweed are great places to look for them.  For some reason they will spend an inordinate amount of time on those flowers.  Grey hairstreak has several generations per year, but you might also find them here as well.  Juniper hairstreak has a second generation that can be found in July--I have never been able to locate them at this time of yearViceroy and have a hard time finding them anyway, but you might be more lucky.
If you happen to visit a savannah area, you might be able to see these hairstreaks chasing each other around the trees.  It is fun to find them on flowers, but it is an even better show to see them doing their pre-mating behaviors.
The most common of the gossamer-winged butterflies will be eastern tailed-blues and summer azures.  In the last couple of years Melissa blues have been seen in central Iowa, in what seems to be a minor range expansion.  Watch for them.
Several of the brushfoot butterflies can be quite common and showy now.  Viceroys are easily found in any area with willow trees.  Monarchs, of course, can be found in open fields and anywhere you can find one of the several species of milkweed found in Iowa.  Red-spotted purples should be somewhat common now--more common in wooded areas.  Common wood nymphs are very active in the prairies right now, and can be found in other areas as well.  Red admirals and painted ladies are everywhere, and if you watch you might see common buckeyes also.
Wet gravel roads are good places to see butterflies mudding.  One of my favorites to find is the question mark butterfly.  From a distance they look like a plain brown butterfly, but up close you can see all kinds of purple and blue colors.
Take a walk in a wooded area and you might have a butterfly come and land on you.  I would bet money that it is a hackberry emperor.
Orange sulfurs will be found in pretty good numbers, with their numbers building over the month. You may see good numbers of white butterflies, which could be either cabbage whites or white forms of orange or clouded sulfurs.  If you are lucky, you might see the rare checkered white.  Little yellows will be found in good numbers where there is a patch of partridge pea.
Many skippers are hard to identify.  Little glassywing, dun, and crossline skippers differ by fairly subtle markings.  Delaware skippers are a little easier to identify by their bright colors.  Look for least skippers in tall vegetation near bodies of water.  Peck's skipper and tawny-edged skipper are a little easier to identify and will be common enough that you are likely to see them.
So get outside and enjoy the butterflies while they are in good numbers.  Some will stick around for a while, but others will be gone within a few weeks.

    
 
  Great spangled fritillary  
  June, 2020   
  Silver-spotted skipperMay gave us wet, cool weather following a late spring.  We had a few warm days with a surprising number of butterflies, but most days had few on the wing.  I expect that to change pretty soon as the season progresses and the days get longer.  June is a great month for butterflies, and during the first week or so I will often see two or three first of the year butterflies each time I go out.
In addition to the great flights of new butterflies, June also brings blooms of flowers that are very good at attracting butterflies--milkweeds, dogbane, and purple coneflowers.
The silver-spotted skipper has several broods and can be found most of the summer.  They can be pretty numerous in June.  They are strong fliers and are easily recognized once you have seen them.  They seem to me like little flying fireplugs, hopping around from flower to flower, often landing underneath the flower and extending the proboscis up to get the drink.  Common checkered skipper, common sootywing, least skipper, tawny-edged skipper, and Peck's skipper are all widespread and can be found most of the summer.  Watch for any of them on milkweeds or dogbane, or along the edges of gravel roads and trails. Most butterflies engage in a behavior called "mudding" or "mud puddling", in which they drink water from damp sand.  It has been reported that ninety percent of the individuals mudding will be males, and that males do his to collect minerals that they pass along to the females during mating.
Skippers can be frustrating to identify at any time, but three that you might see in June can be especially difficult.  Little glassywing, dun, and crossline skippers all can be seen now, sometimes together on the same plant.  There are subtle differences, but you have to see the butterflies at the right angle in order to tell them apart.
The three most common swallowtails--black, giant, and eastern tiger, all have good numbers in June and can be seen all month long.  Zebra and pipevine swallowtails are mostly only found in the south east or south west corners of the state.
Cabbage whites along with clouded and orange sulfurs will soon become the most common butterflies to be seen.
The two most common gossamer-winged butterflies will be the summer azure and the eastern tailed-blue.  Both are quite small, but are likely to be present in large numbers.  You should not need to look too hard to find these.  Bronze copper, American copper, and gray copper are a little more difficult to find, but are quite beautiful when seen.  The gray copper is fairly large and can be found in good numbers in the habitats where it is found--moist prairies.  It does not seem to roam too much, so you won't see it at all unless you are near those habitats.  Although most are pretty rare, hairstreaks can often be found by checking the blooms of milkweeds.  Butterfly milkweed and common milkweed are great for finding the hairstreaks.  The flowers have nectar that is highly attractive to the hairstreaks, but which also encourages them to stay on the flowers for an extended period of time.
pearl crescent Brushfoot butterflies also make quite a showing in June.  Watch for silvery checkerspot in wooded areas (although they can be anywhere).  Pearl crescents are quite common in more open areas.  Gorgone checkerspots can be found in areas with good prairie.
Any place that has willow trees should be good for viceroys.   Red spotted purples can usually be found near woodland areas.  Great spangled fritillaries can be found in a variety of habitats and are often a backyard butterfly.
Anytime from late June to early July is a good time to look for regal fritillaries.  You need to look at a good prairie to find them, and you might only see them from a distance.  They can cover a lot of territory in a short period of time.  They can be found in a number of prairies in central Iowa, including Doolittle, Liska-Stanek, Neal Smith Wildlife refuge, Rolling Thunder, Medora, and a bunch of others.  If you have never been to a prairie in Iowa it is worth your time, but wear long pants, sturdy shoes, and check yourself for ticks afterword.  Also, take plenty of water.
There are several butterflies that are gray or brown and mostly inconspicuously colored, and which spend most of their time on the ground or at least under the vegetation.  These include the northern pearly-eye, the common wood nymph, and the little wood satyr.  They have a tendency to fly down into the weeds when startled, making them difficult to view or to photograph.  Still, they can be quite charming.  The little wood satyr sort of jumps or twitches when mildly startled, as if getting ready to fly.
Of course, American ladies, painted ladies, and red admirals can become quite common during the early summer.  If you are fortunate enough to have a yard you will almost certainly have red admirals.  During the long days of summer red admirals will be very active just before sunset, basking on tree trunks, sidewalks, and patios.  They will sit at a particular spot for a while, then race off in hot pursuit of another red admiral that gets too close.  They provide a great form of entertainment that is not curtailed due to social distancing concerns.
Get out when you can and enjoy the butterflies.

Harlan Ratcliff
 
  Great spangled fritillary  
  May, 2020  
  Antisocial butterflies edition:  I considered ignoring the current situation with the COVID-19 virus, but it was hard to ignore the virus in the room.  meadow fritillaryPlus, I have spent so much time indoors watching bad TV that my mind has turned to mush.  I thought I would talk a little about the social aspects of butterflying.  Keep them in mind while you are practicing your "social distancing."
If you were to go on a butterfly walk you would meet lots of interesting people.  Everyone would be there for the butterflies, but some are there only for the butterflies.  Others are there to see how butterflies fit with what their real interest is.  So you might see butterfly researchers with nets out there.  They are usually pretty good at capturing the butterflies and they will show off their skills.  Usually it is catch and release when they are with a group, but they might kill one or two for "vouchers" when the group is done.  Sometimes they mark and release for later recapture, or they might even clip off a leg prior to release for genetic studies.  These are traditional methods and can be done with a group or by the individual.  You might see butterfly surveyors along the walk as well.  These people are private citizens who have some training and are usually participating in some kind of citizen science project like the Iowa Butterfly Survey Network.  This also can be a group activity or an individual activity.  You might find an environmental educator.  These people have a special calling to explain the wonders of the natural environment to people of all ages, but especially to children.  You might see a botanist.  Botanists wear floppy hats.  You might see a land manager.  Land managers often ask all kinds of insightful questions because they want to know how to manage habitats to maintain and enhance biological diversity, including all kinds of butterflies.  You might see a birder.  Birding can be either a solitary activity or a social one.  If you have birders in the group, one of them will make a special point of making sure that every individual in the group gets a good look at any of the butterflies which represent a new species for the walk.  And you might see the overgrown kid/butterfly photographer.  That's the person out there crawling in the weeds, trying to get the right angle for the butterfly, the flower, and the sky.  This person is well meaning but focused on the task at hand, and probably does not have a good social filter.  It would be great to get all of them together for a nice butterfly excursion sometime this spring, but they are probably all better off getting outside and maintaining a proper social distance from each other.
question mark butterflyButterflies will be somewhat sparse initially this spring because we had freezing weather and snow in mid-April.  That bent the curve, as we are so used to hearing now.  We will be seeing cabbage whites and clouded sulfurs in small numbers.  We should see eastern tiger swallowtails and black swallowtails soon.  If you get to either the south east corner of the state, in Shimek State Forest, or to the south west corner in Waubonsie State Park, you might see zebra swallowtails.  Giant swallowtails will show up in some areas.  They seem to use prickly ash as a host plant, so they can be common in areas with those trees.  Mostly they are rare but the travel long distances and are large enough to be easily seen if they are around.  Red admirals, painted ladies, and American ladies can usually be seen in some of the flowering trees in May, but I think their numbers will be low initially because of the late snow.  Eastern commas can be seen in areas with some woodlands, and by the end of the month you should see more of their slightly larger cousin, the question mark. 
Summer azures and eastern tailed-blues should be out in May.  Both have multiple broods and will have low numbers in May but will become more numerous as the season goes along.  If you are lucky and are near a wetland you might see either a bronze copper or an American copper.  Both seem to be pretty rare now compared to the past.  Pearl crescents show up in May, and can often be seen in mating/fighting trios of two males and a female.  Meadow fritillaries will weave in and out of low flowers. 
Small skippers such as the tawny-edged and Peck's show up for the first time towards the end of May.  The large silver-spotted skipper should also show up by the middle of the month.
This has been a very stressful time, with very real fears of the virus, the unknown, and the economy.  Maintaining some kind of mental health is very important.  It is good to get outside, with other people or without.  State parks are open for day use, and you can usually find a small natural corner of one for some nature appreciation.  State preserves are good, too.  If you have flowers you will see butterflies in your back yard.  So get out in nature.  Listen to the calls of the birds and the frogs.  Learn their names.  Learn the names of the butterflies, too.  Learn the names of the flowers.  If you see a flower and you don't know its name, look for someone with a floppy hat.  Botanists wear floppy hats.
 
  great spangled fritillary  
  March and April, 2020  
  Henry's elfinWe should be seeing butterflies in Iowa soon.  A warm spring day, especially if temperatures at night have been above freezing, will bring them out.  Already there has been a butterfly sighting in Wisconsin, on the Wisconsin Butterflies site.  The butterflies we see first spend the winters here in the adult stage, wedged under loose bark or deep in the leaf litter.  The two most likely to be seen here are the eastern comma and the mourning cloak.  Milbert's tortoiseshell and compton tortoiseshell have similar habits but are very rare this part of the state and not likely to be seen.  Red admirals can also be among the first to be seen.  Their origins as first of the year butterflies in the state are a little murkier.  Red admirals are migratory butterflies, and the first big influx that we see here comes from areas to the south of us.  The butterflies invade, assisted by the winds from the first thunderstorms of the year.  However, a small number of red admirals probably over winter here as well, in either the adult or chrysalis stage.  An early red admiral that is brightly colored and not tattered would indicate the latter.
If you hike through the woodlands early in March you might see butterflies while there is still snow on the ground.  You might see an eastern comma sunning itself high up on the trunk of a tree.  If you see any sap leaking from a broken branch or from holes drilled into the bark by sapsuckers you might see butterflies and other insects drinking that sweet liquid.
As the season progresses there will be more species and more individuals.  Cabbage whites can be seen flying as soon as the earliest wildflowers are blooming.  You might also see black swallowtails early on.  Going into April many trees start to bloom, as do the flowers on the woodland floor.  Eastern tiger swallowtails will make their first appearance in late April, and can often be seen in flowering trees of various types. 
It is probably worthwhile to look for a small, white butterfly called the Olympia marble.  It's caterpillar host plants are mustards--primarily rock cresses.  This butterfly has not been seen much in Iowa lately.  It was probably never common here, and much of the habitat where it originally was found has been destroyed.  However, this butterfly is also been described as secretive, so it is possible that it is still around in some places, but just never observed.
spring azureThere are certain butterflies that I like to call "frustration butterflies."  The Olympia marble is one of them.  So is Henry's elfin.  Frustration butterflies are butterflies I have spent a long time looking for unsuccessfully.  I might go for a hike in an area that I think should have this particular butterfly, and I look for it.  If it is a frustration butterfly I am not likely to find it.
Henry's elfin uses redbud as it's caterpillar host plant.  You can find information about where it is found in Iowa on the Insects of Iowa website for the species, or if you have an account and know how to use the database you might find some information on Bugguide.  So I went to some of those places and looked around.  I looked specifically for redbud trees.  The adults only come out for about a week in mid to late April.  After several years and many unsuccessful trips, I finally was able to see and photograph the butterfly from a distance, as it flew in a redbud in Cordova State Park near Lake Red Rock.  I was quite proud of myself, even though the photos were not very good and only showed a portion of the hindwing of the butterfly.
Since that time, on three different occasions, I have come across fairly good numbers of Henry's elfin.  Each time I saw a half dozen or more and they cooperated with my photography efforts.  Two times I was in Elk Rock State Park, and the other time was in Waubonsie.  The photo above was taken along one of the horse trails in Elk Rock.  I think the butterfly is not terribly rare in Iowa, it is just seldom seen because it only flies for such a short time.
March might seem long for the butterfly watchers, but by mid April things should pick up a little.  Look for spring azures, clouded sulfurs, painted ladies and American ladies by then, in addition to the butterflies already mentioned.
Spring can be a busy time with all kinds of obligations, and it is easy to not get the time to get outside and enjoy nature.  But the seasons progress rapidly and if you don't get out you might miss something that is really amazing.  Take the time.

Good luck finding butterflies.

                                   Harlan Ratcliff
 
  great spangled fritillary