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The Poweshiek Skipper Project | |
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Lake Hawthorne ©Rayford
Ratcliff
Introduction Information about the butterfly
O.
poweshiek, Legacy butterfly Legacy
of Chief Poweshiek
H.W. Parker's writings Von Blixum's Heroic Experiment
Iowa's
biological diversity
The Poweshiek Skipper Project Goals
of the project
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Butterfly Forecasts for Central Iowa October 1 to next spring October in Iowa often has some of the most pleasant
weather. The days can be sunny and warm, but not too warm.
Leaves are often at their most colorful. The Sachem, Atalopedes campestris, shown at right, is a butterfly that emigrates into Iowa from points south each year. This is a male. If it is lucky, it will find at least one female to mate with. That female will carefully place several hundred eggs in many places in various grasses. Some of the eggs will hatch into little caterpillars. None of the eggs or larvae will make it through the Iowa winter, unless we happen to have an exceptional winter. Next year, new sachems will arrive in Iowa from places warm enough to allow them to survive. We will still have a fairly high diversity of butterflies until we get a frost. Monarchs, Danaus plexippus, have mostly left, but there will still be stragglers. The same is true of painted ladies,Vannesa cardui, red admirals, V. atalanta, and the common buckeye, Junonia coenia (below and to the left), all of which have a two-way migration--into Iowa in the spring and summer, and to the south in the fall. Probably most have left, but a few remain. We will continue to see these until we get a hard frost. Black swallowtails, Papilio polyxenes, are still around. Pearl crescents, Phyciodes tharos, are still pretty common. You might see the occasional gray hairstreak, Strymon melinus. The butterflies that over-winter as adults--morning cloaks, Nymphalis antiopa, Eastern commas, Polygonia comma and question marks, P. interrogationis and a few others may show up on sunny days, drinking nectar or sap if they can find it. They will be looking for loose bark or tree cavities to hole up in.
Butterflies prepare as well as they can for the winter. A very small number will survive it as adults. Another small group will not survive but will leave offspring that will. And some, like this buckeye, will go south. I have enjoyed doing the butterfly forecasts this year--thanks for reading them. In general, this year had pretty low numbers compared to past years. Hopefully next year will be better. The butterfly season will continue into October until the weather turns cold. If we are lucky, we may even have a week or two in November. Then we probably won't see another butterfly until March or maybe April. Until then, Harlan Ratcliff |
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Butterfly Forecasts for Central Iowa September 16-30, 2009 The butterfly season is almost over. Already the numbers are starting to decrease. However, there are still a few butterflies that show up late in the year, and you might see them for the first time in late September.
One place I have found them reliably is near Saylorville Reservoir. Go to the west side of the long bridge into Polk City. Lincoln Cemetery is at the intersection of Highway 415 and NW Beaver Drive. On the north side of the cemetery is a sign to Lincoln Access. Follow the Lincoln Access road almost to the bottom of the hill. There is a gravel turn-around there. Park near the turn-around and walk by the pond or the culvert. Look closely. Dainty sulfurs can often be mistaken for small moths. They are very small and don't sit down for long, so they are hard to photograph. There are usually pretty good numbers of dainty sulfurs in the rocky and weedy areas here. While you are in this area, look for gorgone checkerspots, Chlosyne gorgone. Aaron Brees reported seeing some at Saylorville--I assume it was this same area. C. gorgone looks a lot like the very common pearl crescent, Phyciodes tharos from above, but has wild chevron patterns underneath. While you are at it, look for the phaon crescent, P. phaon as well. The phaon crescent has not been recorded in Iowa, but it does range into northern Missouri and close to Iowa in Nebraska. Its reported host plant is fogfruit. If you look in the rocky areas in Lincoln Access, you will see a short plant with a white, button-like flower. That is fogfruit. If you happen to see and especially if you can document phaon let me know. That would be a great find! A range map for P. phaon can be found at: http://www.butterfliesandmoths.org/species?l=1740 Other
butterflies you might see for the first time in the year include fiery
skippers, Hylephila phyleus, zabulon skippers, Poanes
zabulon and a skipper that goes by one name--sachem, or Atalopedes
campestris. The fiery skipper (left) has a fairly distinct pattern on the undersurface of its wings--it is hard to confuse with anything else. From above, on the male, you can see a flame-like pattern--hence the name. Females are darker above and do not show the flames. Monarchs, Danaus plexippus, are migrating now, but you will still continue to see them for a while. You still may see red admirals, Vanessa atalanta, and painted ladies, V. cardui as well. Viceroys, Limenitis archippus, northern pearly-eyes, Enodia anthedon, black swallowtails, Papilio polyxnes, and some others will hang around until the first frost. You may also see some of the butterflies that over-winter as adults: eastern commas, Polygonia comma, question mark butterflies, P. interrogationis, and mourning cloaks, Nymphalis antiopa. The most common butterflies for a while will continue to be the clouded sulfur, Colias philodice and the orange sulfur, C. eurytheme. Watch the show now because it will soon be gone! Harlan Ratcliff. |
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September 1-15, 2009 Is it September already? Where did the summer go? I have some stuff to get done before summer is over. Too late now. Soccer games have started up as has pre-season NFL football. I have started cutting dead elm trees for this winter's firewood, and the kids start to school on Thursday.
I was fortunate enough a few days ago to see the magnificent cloudless sulfur, Phoebis sennae shown to the right. Cloudless sulfurs are larger than our more common clouded and orange sulfurs, Colias philodice and C. eurytheme. They are about the size of a viceroy, Limenitis archippus or a red spotted purple, L. arthemis--not quite monarch size, but getting close. The upper side of the cloudless sulfur is a brilliant light yellow with no markings in the male and a thin dark edge in the female. Due to their large size and lack of dark markings they are easy to differentiate from our more common Colias sulfurs. This butterfly is quite common in some states to the south of Iowa, but quite rare here. You should look for them from now until first frost. Count yourself lucky if you do see one. Speaking of viceroys and red-spotted purples, you may continue to see a few of these butterflies until about the middle of September. When you see them, they will be quite battered looking, as they are getting close to the end of their lives. We won't see adults again until next summer.
Early September can still have large numbers of butterflies, and the numbers are usually dominated by the Colias sulfurs. We have had very low numbers of clouded sulfurs this year compared to "normal" years, so we might not get the butterfly show that we usually get this time of year. Orange sulfurs still seem to have good numbers, and we should start seeing some of the skippers that show up late--fiery skippers, Hylephila phyleus, Sachems, Atalopedes campestris, and common checkered skippers, Pyrgus communis. We should expect to see gray hairstreaks, Strymon melinus as well. Eastern tailed-blues, Everes comyntas, are normally extremely common and a few hang on until late September. However, while they have been around, they have been present in smaller numbers than usual this year. Black swallowtail , Papilio polyxenes numbers have been down as well, and they are usually a late hanger-on. Get out while you have a chance. The butterflies will soon be gone. |
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August 16-31, 2009 Butterfly diversity is peaking right now and the numbers
are high. Numbers will continue to increase into September but the
diversity will slowly taper off. Tall thistles and bull thistles are beginning to bloom now, and they are very attractive to large butterflies. You might see Iowa's largest skipper, the silver-spotted skipper, Epargyreus clarus. It is very fun to watch. Unlike most butterflies, the silver-spotted skipper will often obtain its nectar by landing underneath a flower, then sticking its proboscis over the top of the flower. Most butterflies obtain nectar while walking on top of the flowers. The pair to the left seem to be having a chance encounter and are competing for food from the same bloom. Many of Iowa's butterflies are not true residents but over-winter in the southern states then migrate or immigrate into Iowa each year. Some, like monarchs, Danaus plexippus, painted ladies, Vanessa cardui and red admirals, V. atalanta, have a two-way migration and adults fly south from Iowa each fall. Others seem to have only a one-way flow. The butterflies that enter Iowa each summer die off, and are replenished from southern stocks each year. The
one-way migrants include the gray hairstreak, Strymon melinus, (shown below to the left),
checkered white, Pontia protodice, little yellow, Eurema lisa,
dainty sulfur, Nathalis iole, cloudless sulfur, Phoebis senna,
fiery
skipper, Hylephila phyleus, and sachem, Atalopedes campestris. I don't recall seeing any of those
species yet this year--maybe they will show up soon, but some years they
don't. When butterflies are common, like they are now, you can get some unexpected experiences while traveling. Bicycle trails, especially those that have areas of mixed habitats can have wonderful mixes of butterflies. Enjoy them as they fly overhead but keep your eyes on the road. If you drive somewhere in the country you might see lots of butterflies. As you might expect, there will be more where there are flowers (especially where integrated roadside management is used to re-introduce prairie plants to the ditches where grasses have become monocultures). Take a trip on the Boone and Scenic Valley Railroad and you will be treated to a delightful mix of prairie plants and butterflies, especially some of the larger ones. There seems to be a pretty large population of giant swallowtails, Papilio cresphontes, in the switching yard at Fraser. So get out there and enjoy Iowa's butterflies while they are at their finest. Harlan Ratcliff |
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August 1-15, 2009 Pay close attention to the white butterflies you see at
this time of year. Cabbage white butterflies, Pieris rapae,
have been numerous this
summer, but you will begin to see others. You may be lucky enough to see a white butterfly--larger than a cabbage white and with more black markings like the butterfly on the right. This is a checkered white, Pontia protodice, which probably does not survive Iowa's winters, but immigrates to Iowa each year from the south. There is no evidence of a two way migration for this butterfly. This butterfly is seldom common in Iowa, but can be seen in small numbers most years. If you know where a patch of the annual prairie plant partridge pea can be found you should look for the little yellow butterfly, Eurema lisa. It is smaller than a clouded sulfur, but usually a brighter yellow. Most years that I have watched butterflies they have been somewhat common near their host plant although last year they were almost non-existent in Iowa, and I have not seen any yet this year. Like the other yellow butterflies there are occasionally white forms such as the one shown at the left.
Eastern tailed blues, Everes comyntas, are normally pretty common starting in the first part of July. This year they have been rare, but I have seen good numbers of them in the last couple of days. The tall thistles and bull thistles will probably start to bloom about mid August. They are great places to find large butterflies and many of the skippers. Check blue vervain for a variety of small skippers and swamp milkweed for the skippers and many of the larger butterflies as well. Both are blooming now. I have seen a few bronze coppers, Lycaena hyllus lately. They are not terribly common and are small but are brilliantly colored so they do show up will. If you find a good prairie you can look for regal fritillaries, Speyeria idalia. They look remarkably like monarchs, Danaus plexippus from a distance but if you see them up close they are easy to tell apart. You might have to go fairly early in the morning to see them sitting on something. Otherwise they are very active and don't stay in one place for long. Get out there soon, though, because the butterflying does not get much better than it is right now. |
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July 16-31, 2009 A few years back I set up a network of volunteers to survey for
butterflies and look for the Poweshiek skipper in Poweshiek
County and the Counties adjacent to it. Volunteers were mostly looking
in known prairie areas. I was a little surprised to find that the
most common butterfly in these areas at this time was the common wood
nymph, Cercyonis pegala. The common wood nymph is a fairly large butterfly which has inconspicuous markings. It is mostly brown with dark eyespots. Sometimes it is so dark that is it almost black. The undersurface of the forewing on some individuals has a creamy yellow patch in the area of the two large eyespots. The photograph to the right is somewhat unusual because this butterfly is not often seen obtaining nectar from flowers. It is more often seen in its hopping flight, low to the ground. It usually doesn't land on flowers but rather hides in and under grasses and other vegetation. Since it is not showy and does not spend so much time in the open it seems less common than it is. It does not show up in my suburban area surveys at all--it seems to need the structure of tall grasses or dense brush. Generally speaking, larger butterflies live longer than smaller
butterflies. The eastern tiger swallowtail, Papilio glaucus
is the second largest butterfly in Iowa. It usually
has two broods in Iowa although it may have a third late brood (Schlicht,
et. al., 2007). In general it can be found all summer long from
when it emerges in late April or early May until the first frost.
The older it gets the more beaten up and battered it will be. In late July you will see many different butterflies and fairly large numbers of them. Watch for great spangled fritillaries, Speyeria cybele, giant swallowtails, Papilio cresphontes, red spotted purples, Limenitis arthemis, monarchs, Danaus plexippus, painted ladies, Vanessa cardui, and other large butterflies on large flowers like purple coneflower, swamp milkweed, and thistles. Watch for smaller butterflies--eastern tailed blues, Everes comyntas, coppers and several varieties of skippers on hoary and blue vervain and swamp milkweed. A group of butterflies do not over winter in Iowa nor do they have a two-way migration, but populate the state each year from areas to the south of us. These include the usually common little yellow, Eurema lisa, and the less common cloudless sulfur, Phoebis sennae, checkered white, Pontia proyodice and dainty sulfurs, Nathalis iole. Individuals of these butterflies should start showing up towards the end of July. It is a great time to get out and photograph butterflies. Good luck, and take a few precautions against the heat. Have fun! |
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July 1-15, 2009 Butterflies are starting to be present in larger
numbers now, and the diversity levels are very high. Some of the
rarely seen butterflies make their only appearance now, particularly some
of the hairstreaks. Butterfly milkweed is starting to bloom in the
prairie and savannah areas now, and you should check it wherever you see
it. Many species use this plant for a nectar source, and they
often spend significant time on the flowers, which aids the would-be
photographer greatly. It is such a great plant for butterfly
phototography that it is featured in both photos from this entry. This hickory hairstreak, Satyrium caryaevorum, shown to the right was found near a railroad right-of-way by Grinnell. It is mainly a savannah butterfly, and has only one generation per year. Butterflies are numerous enough now that you may start to notice their courtship and aggressive displays. Red admirals, Vanessa atalanta, will perch head down high up in trees and chase anything that flies by them. I often see northern pearly-eyes, Enodia anthedon, flying in to the middle of a large lilac bush we have, where they chase each other around. Pearly crescents, Phyciodes tharos, often form trios of two males chasing one female (the males seem to ignore the female at times and chase each other). I watched this happen when I took the photo below to the left, but I only got one of the males in the photo. I watched a summer azure, Celastrina neglecta, the other day take a slow flight from the top of a tall tree to an area about six feet above the ground near a wildflower patch in our yard. There it was met by another insect which was frenetically flying in circles. The summer azure did a loop and then peeled off, and another insect joined the circling frenzy. They circled each other with such energy and continued for more than a minute. Finally I just had to check it out to see what they were. The acrobatic insects were eight-spotted forester moths, Alypia octomaculata, day-flying moths that are often mistaken for butterflies.
And of course I am looking for the Powesheik skipper now. I have visited two sites that were known to have them in the past but have been frustrated in my search so far. I visited Anderson Prairie near Estherville and got some photographs of variegated fritillaries and long dash skippers, but no O. poweshiek. I visited Hoffman Prairie but there were strong steady winds when I got there (after a 2 hour drive) and I saw no butterflies at all. The wind was keeping them all down. Get outside and enjoy the butterflies. Now is the time to see them! |
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June 16-30 2009 Butterfly numbers and diversity will start picking up in
the last two weeks of June. Some of the most common butterflies have
more than one generation per year, and their second generation starts
showing up now.
Many of the larger butterflies like the swallowtails and great spangled fritillary emerge as adults and will live from a few weeks to most of the summer. Look for them to be fresh now and more raggedy as the summer progresses. Some of the rarer butterflies show up in late June and early July. Look for many of the smaller hairstreaks like the coral hairstreak, Satryium titus, hickory hairstreak, S. calamus, Acadian hairstreak, S. acadica, and Edwards hairstreak, S. edwardsii this time of year. Look for the coral, hickory, and Edwards hairstreaks in good savannah areas and especially on butterfly milkweed if you can find it. Look for the Acadian hairstreak in good wetland areas. The butterfly that is the namesake of this web site, Oarisma poweshiek, emerges starting in about the last week in June and into the first week or two of July. Look for it and let me know if you find it (I can be contacted at bugs@crosspaths.net). It has only been seen in two sites in Iowa in the last couple of years. There is a special show that nature puts on every summer. It is wonderful to watch. But watch closely and don't blink because if you do you will be likely to miss something. |
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June 1-15, 2009 I have been conducting informal surveys for butterflies
since 2003 in the cantonment area at Camp Dodge . This year numbers have been very low. However, since most of the butterflies I count in the early part of the year are clouded sulfurs the reduction in total numbers might be mostly because of a lack of that particular species. I took a trip to Dubuque a couple of weeks ago and saw clouded sulfurs in high numbers--sort of what I would expect here. However, even when I have gone past hay fields where the clouded sulfurs are usually found in very high numbers, I have seen low numbers or none at all. Butterfly numbers are
usually low at this time of year. However it seems to me that they
are a little lower than normal this year. I have not yet seen the
skippers that I predicted for the first part of the month.
Hopefully they are just slow and will show up soon. Diversity and numbers for early June are similar to those in May. You will see a noticeable increase in numbers toward the end of the month, and diversity will gradually increase as well. Look for butterflies like this red-spotted purple, Limenitis arthemis astyanax near wooded areas. This one was attracted to the moisture on a wet gravel parking lot. Gravel roads can be good places to find butterflies, especially on the edges of the road where the canopy of weeds keeps the edge of the road wet with dew in the late morning. There are a number of other interesting insects out at this time of year as well. Tiger beetles are out, as well as several species of dragonflies and damselflies. There are a number of interesting bee species out. Of course, the most magical of insects, the fireflies are making their appearance. What is more wondrous on a warm summer night than watching children chasing fireflies? Turn off the T.V. and get outside. |
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May 16-31, 2009 Butterfly numbers are still pretty low, but the diversity is starting
to pick up. About half of the species that may be seen in Iowa can
be seen in late May, but the probabilities are low because the numbers are
low. You will see more butterflies on one average day in September
than you will see in the entire month of May. You may start seeing some of the Vanessa species, such as the painted lady, V. cardui shown at right. If you do see them now you will probably see battered, ragged individuals like this one. You may also see the red admiral, V. atalanta in a similar condition. A third species, V. virginiensis, or the American lady, is also found in Iowa. These butterflies are so ragged-looking because they are old and they have flown long distances. These species are truly migratory, similar to the monarch. These butterflies fly south in the fall, and a different generation of the same species flies back north in the spring, generally going with prevailing winds. The migration of monarchs is so well known that some people assume that all butterflies are migratory. Not true. Monarchs, the three Vanessa species, and the common buckeye, Junonia coenia all seem to have a two-way migration. More than a hundred Iowa species do not.
The natural history and migration patterns the red admiral and the painted lady species are described on a website maintained by Dr. Royce Bitzer at: http://www.public.iastate.edu/~mariposa/homepage.html Some of the more common species you should also be seeing in the last part of May include: Black swallowtail, Papilio polyxenes, eastern tiger swallowtail, P. glaucus, giant swallowtail, P. cresphontes, cabbage white, Pieris rapae, clouded sulfur, Colias philodice, orange sulfur, C. eurytheme, bronze copper, Lycaena hyllus, eastern tailed-blue, Everest comyntas, monarch, Danaus plexippus, pearl crescent, Phycidoes tharos, summer azure, Celastrina ladon neglecta, silver-spotted skipper, Epargyreus clarus, common sooty wing, Pholisora catullus, Peck's skipper, Polites peckius, and hobomok skipper, Poanes hobomok. While it is a non-native plant, I find dame's rocket to be a particularly good butterfly attracting flower at this time of year. Watch clusters of this flower for skippers, especially. This spring there have been a few reports of goatweed leafwing, Anaea andria in southeastern Iowa. This butterfly is fairly common in the southern part of the United States, but Iowa is at the northern tip of its range. As a result, it is not often seen in Iowa. Look for it--it may be more common than normal this year. Butterfly action should be picking up really soon. Get out and enjoy! |
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May 1-15, 2009 As the weather heats up so does the butterfly
season. The diversity of species you may see in the first part of this
month is fairly high, although the numbers can still be low. It might be interesting to focus on two of the smaller butterflies. Both of these butterflies belong to the group called the grass skippers, which is the group O. poweshiek belongs to. Both show up for the first time in about the second week in May. Both can be present until about the first week of June. Peck's skipper, Polites peckius is shown on the right. It will show up later in the year as well. The Hobomok skipper, Poanes hobomok is shown below on the left. The Hobomok skipper seems to only have one flight in Iowa and will not show up later in the summer. These are entertaining butterflies to watch, and can often be seen at the same time in a small flower bed. Grass skippers have a characteristic pose which can be likened to a jet fighter--one pair of wings is stretched out horizontally, and the other pair is close to a 45 degree angle. If you spot these butterflies, you will almost certainly see them basking, and you will see them chasing each other in groups of three and sometimes four in a mating competition. P. hobomok
is a little bit larger and bulkier than P. peckius, so with a
little bit of observation you should be able to easily tell them
apart. In addition to these two skippers, you will probably see the
tawney-edged skipper, Polites themistocles, another grass skipper
which is mostly brown, and you may see a very black spread-wing skipper, Pholisora
catullus, or the common sootywing. Of the larger butterflies, you should still be seeing good numbers of cabbage whites, Pieris rapae. The most common medium sized butterflies in Iowa, the clouded and orange sulfurs, Colias philodice and C. eurytheme and their hybrids will make their first appearances. You may see the very large eastern tiger swallowtail, Papilio glaucus. Red admirals, Vanessa atalanta and painted ladies, V. cardui, may also be present. You might see the first monarch, Danaus plexippus, of the year. The numbers of individuals you will see is still pretty low. An hour of observation in a suburban area with closely cropped grass would be likely to yield single-digit numbers of butterflies. If you find a good habitat--a woodland, prairie, or wetland with lots of flowers blooming you will probably average one sighting every two or three minutes. As the season progresses, both the diversity and numbers will increase. You might also want to watch for some of the other charismatic insects--dragonflies and damselflies will be making their appearances, as well as tiger beetles, bumble bees, and a host of other insects that are colorful and fun to watch. Take some time to watch the insects. |
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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.
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. |
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April 1-15, 2009 I went out on a limb and predicted that someone would see a mourning cloak in Iowa by the end of the first week in March this year. To my knowledge, that did not happen. I did get a report of a butterfly sighted in western Iowa on March 4th, but it was not identified to species. From an email correspondence it might have been an eastern comma (below to the right) , but we really don't know.
We should still be seeing some of the butterflies which have over-wintered as adults--the mourning cloak, question mark, and eastern comma. The gray comma and green comma and Milbert's and Compton tortoiseshells would also fit into this group but are fairly rare in the central part of Iowa and you should count yourself lucky if you see them. The eastern comma and question mark butterflies, and possibly some of the others mentioned have seasonal morphs. The coloration of the forms that over-winter is different from the forms that emerge as adults in the early summer. The eastern comma shown here is a winter form. The summer form has darker hindwings without the lighter markings toward the edge of the wing. Hopefully we will also start to see some of the
butterflies that over-winter as pupa and emerge as adults. The most
common of those early on are the black swallowtail, the cabbage white, and
the spring azure. Also, depending on the weather we might start
seeing some of the butterflies that over-winter in the southern areas and
migrate into Iowa in the summer. These include the painted lady, the
red admiral, the common buckeye, and the American lady. Of those, the American lady may be less migratory--it is thought that some migrate and some are able to over-winter in Iowa. To the left is a female black swallowtail. Females have more blue on their hindwings than males do, and typically have smaller yellow markings on their forewings. Early April can still be a pretty sparse time for butterflies. The weather has a huge impact on butterfly activity. Warm sunny days with temperatures above freezing at night will bring them out. Cold and rainy days (and we can still get snow this time of year), or freezing temperatures at night will result in few if any butterflies. But get outside. Play hooky if you have to and see what you can find. |
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March, 2009 Winter is leaving us slowly. We are starting to get a few spring-like days in between the days of snow and ice. I am ready for good weather to get here.. Last year I posted my
butterfly forecasts to a couple of list-serves, or you might have seen it posted on a couple of
web sites. For those of you seeing this for the first time, welcome. For those of you who saw it last year, welcome back. The purpose of this forecast is to give you some idea of the butterflies you might see throughout the season. Sometimes I will throw in other creatures. And I mention generally with what you will find in central Iowa. March is not a good time for butterfly diversity. However, after a long winter it is a thrill to see any butterflies at all. If you go out in the woodlands on a nice sunny day you should look at the tree trunks for any sign of unexpected dampness. When the sap starts to flow it can leak out from wounds on the tree--cracks in the crotches of the branches for example. There are also birds--sapsuckers--that drill small holes in the trunks. Insects will be attracted to the sugary solution that is present. There you might see the first butterfly you are likely to see in the spring, the mourning cloak, Nymphalis antiopa. Above right is a mourning cloak that I saw early one spring day in Cedar Bluffs State Preserve in Mahaska County.
Of course, it all depends on the weather. You need a sunny day of at least 50 degrees F. to see most of these butterflies although the mourning cloak might be seen with temperatures as low as 45 as long as the sun is shining brightly. The higher the temperature the more likely they will be out. The butterflies mentioned so far are all woodland butterflies. And while you are in the woods be sure to look for the early spring flora like the hepatica shown in the photo above left. Sharp lobed hepatica is often the first flower that blooms in the spring, or at least one of the first. By the last week of March some of the more common butterflies that over-winter as pupae may be seen (depending on the weather). These include the cabbage white, Pieris rapae, the black swallowtail, Papilio polyxenes, and the spring azure, Celestrina ladon. I have included a checklist of Iowa butterflies here for those interested. This checklist is designed for beginners and is meant to teach people how to do butterfly surveys. The species highlighted in gray are the most common. Page numbers to photographs in two common field guides (see the top of page 1) are shown next to the name of the butterfly. If you think you know what it is but are not sure the page number gives you a quick reference. Now get outside and have some fun! Harlan Ratcliff References: Schlicht, Dennis, John C. Downey, and Jeffrey C. Nekola. 2007. The Butterflies of Iowa. The University of Iowa Press, Iowa City, IA. Scott, James A. 1986. The Butterflies of North America. A Natural History and Field Guide. Stanford University Press, Stanford CA. IA-BTRFLY: The Iowa Butterfly and Dragonfly list serve. www.wisconsinbutterflies.org sightings page. www.NABA.org sightings page. Ratcliff, Harlan: 2003-2008 Unpublished butterfly survey results.
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Flowers
are still blooming--at least the asters and some others. Butterflies
are still around but will soon be gone.
Once
the frost gets here, the diversity will go way down. We will
continue to see clouded and orange sulfurs, (Colias philodace and
C. eurytheme),cabbage whites, Pieris rapae and
possibly a fiery skipper, Hylephila phyleus or a sachem before
the weather gets too cold for any butterfly.
The
dainty sulfur, Nathalis iole, is a very small butterfly--about the size of some of the
small blues. It is one of the butterflies that over-winters in the
southern United States, then emigrates to Iowa late in the summer.
In my experience you will not see this butterfly most places.
However, where they found they are often very common.
If
we get seasonal weather instead of the unseasonably cold weather we have
had lately we should still get some good butterflies. If it turns
cold and rainy the butterflies might just fade away.
Monarchs,
Danaus plexippus, are gathering for their migrations. You
may see them clustered together on trees or tall prairie plants.
Red admirals, Vanessa atalanta, and painted ladies, V. cardui
also migrate, although they do it in a more dispersed fashion. I
have seen a number of both species recently which have been in very
colorful condition--apparently recently emerged. The red admiral
to the left is an example. We may see sudden population explosions
of either species due to local emergence or migration.
Clouded sulfurs, Colias philodice and their cousins, the orange sulfurs,
C. eurytheme are normally yellow
in the hot weather but have white forms--usually female--which show up
after cooler weather. Normally this is later in the fall, but this
year with the cool July temperatures I am seeing a higher percentage of
white forms than would be expected for this time of year. Suddenly
the white butterflies you see are more likely to be sulfurs than cabbage
whites.
Butterfly
diversity and numbers will continue to increase, with the diversity
reaching a peak in mid to late August. Many older, ragged
individuals will be seen, particularly in the larger species like
swallowtails and great spangled fritillaries, Speyeria cybele. However, young,
freshly emerged individuals will continue to show up. 
The
species is sexually dimorphic, and has two distinct female forms. The individual to the
left is a male, with relatively
small amounts of blue coloring. Females may look like this one
only with more blue on the hind wings or they may appear mostly black.
Common
large butterflies flying now include monarchs, Danaus plexippus, great spangled
fritillaries, Speyeria cybele, black swallowtails, Papilio polyxenes
and painted ladies, Vanessa cardui. Look for
the summer morphs of both the question mark, Polygonia interrogationis
and eastern comma, P. comma butterflies
now. On the summer morphs, the upper surface of the hind wing is
almost completely dark. The forms that emerge later in the summer
will have lighter upper surfaces than those you will see now.
There is a little bit of a mystery about one (or maybe two) of them.
The spring azure, Celastrina ladon, is often one of the first
butterflies seen in the spring. There is a very similar butterfly
that shows up later in the year (about now) that is called the summer
azure. Two individuals of that species can be seen to the
right. There is some dispute as to whether it is a separate species
or a subspecies of the spring azure--either C. neglecta (as a
species) or C. ladon neglecta (as a subspecies). The taxonomy is best left to the experts, but
look for this butterfly now. You can easily tell them from the other
common blue butterfly, the eastern tailed-blue, Everes comyntas, by
the flight patterns of each. The azures fly up into the trees when
frightened and the eastern tailed-blues stay at the level of tall
weeds. The second generation of the eastern-tailed blue usually
shows up about one to two weeks after the second generation of
azures. If you live in western Iowa look for the Melissa blue, Lycaeides
melissa, in prairie areas. A blue butterfly that is very rare in
Iowa, Reakirt's blue, Hemiargus isola is common in the southwestern
United States. It may immigrate into the state, although there is
some speculation that it is also able to over-winter here in some
habitats.
You
may also start seeing some of the coppers. The bronze copper, Lycaena
hyllus, shown at left is fairly widespread. While
it is not too common or large it is quite colorful and conspicuous so you
will probably notice it if it is around. The gray copper, L.
dione can be found in good prairies and wetland areas. The
American copper, L. phlaes is much smaller than the other two and
not seen as often but can be common in some habitats.
This is fundamentally like a suburb--sidewalks, roads, buildings, and
closely cropped grass. The only flowers are the weeds that
grow in the lawn or the cracks in the sidewalks--dandelions,
clovers, and small weedy mustards. Typically about half the
butterflies I count are either clouded sulfurs, Colias philodice,
(as seen to the right) or orange sulfurs, C. eurytheme.
Clouded sulfurs are the most prevalent early. One
quarter of the butterflies seen annually are eastern-tailed blues, Everest
comyntas. and the rest are distributed in small
numbers over the thirty or so species I see each year. 
The
American Lady is pictured on the left. Notice that it has two
eyespots on its lower hind wing, as opposed to the five for the painted
lady.
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.
The
first butterflies that were positively identified to species in Iowa that
I am aware of were a number of eastern commas seen in Fort Des Moines Park
and reported to the Iowa Native Plants list serve Julia McGuire by on
March 17. Marcia O'Conner reported seeing a gray comma in Wisconsin
on March 16. There were a number of postings to the Wisconsin
Butterflies web site of eastern commas and Mourning Cloaks over the next
several days. I finally saw my first butterfly of the year, an
eastern comma, on March 21.
The
first butterflies you see each year will be those that over-winter as
adults. The list includes the mourning cloak, eastern comma, Polygonia
comma, question mark, Polygonia interrogationis, Milbert's
tortoiseshell, Nymphalis milberti and Compton tortoiseshell, Mympahlis
vau-album. In my experience the tortoiseshells are not common
at all in central Iowa.