Hills of Gold

by Carl Strang

This year’s chapter in the bioblitz series organized by the Indiana Academy of Science was called Hills of Gold. It was on a beautiful site being assembled by the Central Indiana Land Trust, and when complete will occupy around 2 square miles in Johnson County, south of Indianapolis.

The event took place on an intermittently rainy day, as illustrated by this less than sharp image of a representative bit of forest and one of the old logging trails we used to get around the site.

The event took place on an intermittently rainy day, as illustrated by this less than sharp image of a representative bit of forest and one of the old logging trails we used to get around the site.

Usually my role in these bioblitzes is to survey singing insects, but this was too early in the season for a sufficient number of species to justify my participating. I decided to reconnect with my experience studying forest Lepidoptera ecology in the 1980’s, and took on moths as well. As I walked the forest during the day, I found many beautiful plants and animals outside my target groups that gave joy.

Green dragons always make me smile, and I ran across a magnificent cluster of them along one of the streams.

Green dragons always make me smile, and I ran across a magnificent cluster of them along one of the streams.

And who can say “no” to fire pinks? Hummingbirds sure don’t.

And who can say “no” to fire pinks? Hummingbirds sure don’t.

Violet wood sorrel is a plant I haven’t encountered very often.

Violet wood sorrel is a plant I haven’t encountered very often.

There also were insects to note outside my target groups.

This Bombus impatiens queen still had not found a nest site, and was prospecting the forest floor.

This Bombus impatiens queen still had not found a nest site, and was prospecting the forest floor.

I interrupted this female scorpionfly’s feed on an emptied caterpillar skin.

I interrupted this female scorpionfly’s feed on an emptied caterpillar skin.

Speaking of caterpillars, the first target species I found was this eastern tent caterpillar:

They already had reached the final instar and were starting to pupate.

They already had reached the final instar and were starting to pupate.

I collected only four moth species during the day. All were fairly common.

This was one of them, which I identify as the unadorned carpet, a member of the inchworm family.

This was one of them, which I identify as the unadorned carpet, a member of the inchworm family.

Many more moths came to my ultraviolet light setup that night. Stay tuned for that episode.

For the record, there was one singing insect. This was my first encounter with a wood cricket. I heard them scattered thinly all through the forest, but never succeeded in seeing one. They probably were northern wood crickets (Gryllus vernalis), but might have been southern wood crickets (G. fultoni). I made a couple good sound recordings, which I hope will allow me to make the determination.

One of them was singing from this patch of leaf litter.

One of them was singing from this patch of leaf litter.

More on that later, after I have analyzed the recordings.

Literature Review: Carefully Assessing Hazards

by Carl Strang

The Internet is a tremendous resource, providing ready access to all kinds of information. It also has become the foundation for significant social networking. Those two benefits have their dark side, however, as rumors and half-baked ideas spread readily and take on a semblance of fact. These might be amusing, except that they can take a nasty political turn, as in the attack on the American president’s legitimate citizenship, or unsupported fears regarding vaccines or genetically modified crop plants. Concerns about the measured declines in pollinator insects have drawn a lot of attention, and a wide range of hypotheses. This is good, as science works from hypotheses. The next step is to test these, but as is the case for the speculations listed above, lots of people want to jump directly from possibility to voting decisions or legislation without waiting for the results to come in. This week’s selected study from the 2013 scientific literature is an example of how possibilities need to be tested and sorted out. The results are not simple and straightforward the way Internet fear- and rumor-mongers would have it. The study focused on certain insecticides, white clover and our most common species of bumble bee.

Bombus impatiens worker. This is practically the only species of bumble bee we see in the Chicago area from August on.

Bombus impatiens worker. This is practically the only species of bumble bee we see in the Chicago area from August on.

White clover flower. This introduced legume has flowers strongly attractive to bees.

White clover flower. This introduced legume has flowers strongly attractive to bees.

Larson JL, Redmond CT, Potter DA (2013) Assessing Insecticide Hazard to Bumble Bees Foraging on Flowering Weeds in Treated Lawns. PLoS ONE 8(6): e66375. doi:10.1371/journal.pone.0066375

They looked at Bombus impatiens colony responses to lawns with white clover that were treated with two different lawn insecticides. Neither insecticide affected the bees if flowers present at spraying time were mowed from the plants. One of the insecticides (chlorantraniliprole) did not affect the bees, the other (chlothianidin, a neonicotinoid) affected bees that visited flowers that had been sprayed. New flowers opening after spray application did not affect bees.

Ecological interactions are complex. Biochemistry is complex. We humans have developed tools that help us deal with such complexity. Reason and intuition are two such tools, but when addressing real world problems involving physical entities or processes the formalized use of reason (i.e., science) is needed if we are to have clear and unambiguous answers. The fear-mongers manipulate peoples’ intuition to shape statements that sound right, but without the tedious sorting out of hypotheses through scientific studies such fearsome forecasts have to be regarded as nothing more than possibilities.

First Flowers

by Carl Strang

Spring advances, despite the unpleasant weather that has denied our enjoyment of much of it so far. As I have sloshed through the rain and the mud at Mayslake Forest Preserve, I have been finding the first of the woodland wildflowers, so I guess it hasn’t really been as cold as I have thought.

Bloodroots have been blooming for what seems an extended period, though. Perhaps the temperatures have been marginal for them.

Lots of spring beauties have taken advantage of last fall’s burn in the south savanna.

These haven’t hit their peak, yet.

Views of pollinators still have been few.

In addition to this bee fly, I have seen the first of the year’s queen Bombus impatiens bumblebees.

The expansion of the Dutchman’s breeches population is gratifying.

These make me smile whenever I see them.

Ongoing restoration clearing of buckthorn has shown the quickest response by trout lilies, which now can be found in great numbers in many places on the preserve.

Their flowers haven’t been open on many days, yet, needing temperatures above 50F or so.

It’s a little early yet to do a serious phenological comparison, but so far, compared to the last two years at Mayslake, first flower dates in 2011 have been the earliest for one species, latest for 2 species, and between those of 2009 and 2010 for 5 species.

Odd Bee Identified

by Carl Strang

The Beespotter folks got back to me in recent days and confirmed that the odd bumblebee I reported earlier was indeed a male Bombus bimaculatus.

This confirms in my mind that bimaculatus is an early-season species in northeast Illinois, as males appear toward the end of a species’ season. In support of that notion, in recent days I have seen increasing numbers of Bombus impatiens, the common late-season short-tongued species, as they replace the declining bimaculatus.

Odd Bee, and Tour de France Catalpas

by Carl Strang

In the late afternoon of July 4 I was looking out the kitchen window at my prairie garden plots. Bumblebees, Bombus bimaculatus, were swarming the Culver’s root

and wild bergamot.

They were not showing very good fidelity, individual bees frequently going between the flower species rather than sticking to one. Then I saw a bee that immediately sent me grabbing for my camera. Like the bimaculatus it was moving between Culver’s root and bergamot.

This bee was almost all yellow.

What was wrong about it was the black abdominal segment in the middle of the yellow. If not for that, I would have passed it off as a Bombus fervidus. But fervidus should have a black strip between the wings, as in this one I photographed last year:

I did a web search, and found a photo of a bee somewhat similar to this one at a University of Illinois website. It was identified as an aberrant male Bombus bimaculatus. The eyes of the one in my yard seemed small, however, for a male.

Also, it seems early in the season for males to appear unless, as I suspect from last year’s observations, bimaculatus is limited to the early part of the year and is replaced by another short-tongued species, B. impatiens, in the latter part of the season. I decided to resolve this problem by creating an account in Beespotter and submitting my photos to the specialists there. I’ll report back with the results later.

P.S. In last night’s TV coverage of the Tour de France, the broadcast announcers’ table was placed in front of some catalpa trees in bloom. The British and American announcers all wondered aloud at one point what the trees were. I’m not sure which catalpa species it was, but clearly these or their ancestors had been transplanted from North America to that location in Spa, Belgium, for their floral display at this time of year.

Late Bee?

by Carl Strang

On May 20 at Mayslake Forest Preserve I saw this queen Bombus impatiens bumblebee digging in a small area in the south savanna.

There had been many days of warm weather, and so I would have thought by that point all the queens would have found nest sites and begun their first broods. Already I was seeing worker Bombus bimaculatus in my garden at home. So, what was the digging queen’s story? I don’t know any other reason why a queen would dig. If she sensed a cavity in the soil below that spot, a little digging might get her a nest hole. It seemed late to be searching still. Perhaps she had a nest, lost it, and had to start over.

On the other hand, given her species it’s not a total disaster. Bombus impatiens is the one species whose activity spanned the entire season at Mayslake last year. I saw them as late as October 5. The latest other bumblebee was a B. griseocollis on August 25. I haven’t been studying bumblebees long enough to know whether this is typical, but in any case it seems there still is plenty of time for this impatiens queen to get going.

Early Insects

by Carl Strang

This spring, plants have been flowering a couple weeks ahead of last year, and some of the insects are making early appearances as well. This spring azure butterfly was out by April 12 at Mayslake Forest Preserve.

The earliest dragonfly of the year always is the migratory common green darner, the first of which showed up on April 5. That’s one of my earliest observation dates for the species. Last week I found a few other odonates at the stream corridor marsh, including this pair of common spreadwings in wheel position.

There also were both eastern and fragile forktails, the latter a new preserve record. Another new insect for the Mayslake list was this skipper, which I believe is a Juvenal’s duskywing.

A colony of eastern tent caterpillars is well under way north of the off-leash dog area.

To the right of the nest you can see the egg mass from which the caterpillars emerged.

Though flowers are blooming earlier, pollinators have not been caught napping. Here a carpenter bee visits cut-leaved toothwort flowers.

At first I thought it might be a Bombus impatiens worker, but the queens of that bumblebee species still seem to be searching for nest sites. At most they are beginning to tend their first set of larvae. The lack of yellow on the relatively hairless abdomen of this individual rules out all bumblebees.

Finally, I can declare the singing insect season to be open. The first greenstriped grasshoppers were displaying at Mayslake on April 20. In my 5 years’ experience with singing insects this is the earliest crepitation I have heard from that species, by 8 days.

Miscellaneous U.P. Notes

by Carl Strang

In this final chapter of my Michigan vacation account, I will bring together assorted observations of other animals and sights. None of this truly counts as inquiry, except that travel and the exposure it gives us to new places leads us to make comparisons with our familiar environment. Such comparisons often lead to questions and inquiries on down the line.

At Muskallonge Lake, after completing my investigation at the beach, I went for a walk along the state park’s trails.

Muskallonge Lake trail b

There were spectacular views of Lake Superior from elevated points, and flocks of migrating songbirds to investigate.

Tahquamenon Falls State Park is named for various waterfalls along the Tahquamenon River. Especially spectacular are the upper falls.

Tahquamenon Falls upper 1b

After a summer in which I made good progress in my knowledge of Illinois bumblebees, I was interested to find that in that part of the U.P., as back home, only one common species of short-tongued, generalist bumblebee is active at this point in the season. Here it’s Bombus impatiens; at the tip of the U.P. it was the beautifully marked Bombus ternarius.

Bombus ternarius 2b

B. ternarius is a northern species that does not extend its range down to Illinois.

One of the more charismatic birds that one hears and, sometimes, sees in the north woods is the pileated woodpecker. Here is a tree that has been well worked by that species.

Pileated work b

Beauty on a smaller scale, which provided a reminder of the season in transition, took the form of this aspen leaf lying on a trail.

Aspen leaf 1b

I spent most of my time at Whitefish Point. Here is a small scene I found especially compelling.

Whitefish Point 7b

As I walked out from the point to the parking lot for the final time, I found an enchanting little animal crossing the trail.

Smooth green snake 3b

Smooth green snakes occur in many places, but are so well camouflaged that we seldom have the good fortune to see them.

On my final morning at the Tahquamenon Falls campground, I found that a large number of moths had been drawn to the restroom building’s lights.

Nepytia canosaria 1b

These were nearly all males of the same species, emerging all at once.

Nepytia canosaria 3b

Nepytia canosaria, the false hemlock looper moth, is a common northern species whose larvae feed on a wide range of coniferous species including firs, hemlock, pines and spruces.

Progress on Bumblebees

by Carl Strang

Earlier I posted some background on bumblebees . I find that I made an error or two there, I since have found additional species at Mayslake Forest Preserve, and also some added web sites specific to Illinois bumblebees that have helped immensely. The total list for Mayslake at this point includes 5 species, and I showed a photo from Fullersburg Woods of a 6th, Bombus vagans, in that earlier post. There are 9 species total for Illinois, of which 2 are rare. (Here I am not counting the nest-parasite “cuckoo bumblebees,” of which there are 2, but which I have not yet encountered). To this point in the season, the most common species has been Bombus bimaculatus, both at Mayslake and in my garden at home. It has a yellow thorax except for a black dot on top, the first (basal) abdominal segment is yellow, the second segment is yellow in the center front edge but black on the ends and back edge. Otherwise the abdomen is black.

Bombus bimaculatus 2b

The patch of yellow on the second segment often is small and hidden by the wings, so care is needed to distinguish bimaculatus from another common species (though perhaps less common locally than I implied in that earlier post), Bombus impatiens. The main difference from bimaculatus is that the yellow on impatiens’ abdomen is confined to the first segment.

Bombus impatiens queen 2b

One correction I need to make to that earlier post is that the dead bumblebee I featured was not Bombus fervidus after all. That bee had a black basal abdominal segment, where in fervidus the first 4 segments all are yellow. I have found a few live members of the dead bee’s species at Mayslake.

Bombus auricomus 10b

This is Bombus auricomus, which is regarded as “uncommon” in Illinois. Here, the first segment is entirely black, segments 2 and 3 entirely yellow. The sides of the thorax are black, and as the next photo shows, there is a large black area in the center of the dorsal (top) thorax.

Bombus auricomus 2b

At Mayslake I have seen only a few of these, always in the same place, so I believe there is only one colony of them on the preserve. Compared to other bumblebees they are large and very active. Bombus fervidus is at Mayslake, too.

Bombus fervidus 3b

Here you can see that the basal segment also is yellow, as is the entire thorax except for a black band across the back between the wings. In that earlier post I mentioned the ecological significance of differences in tongue lengths among species. Get a load of the tongue length on that fervidus!

Bombus fervidus tongue b

The 5th Mayslake species to date is Bombus griseocollis.

Bombus griseocollis swamp milkweed 3b

In this one the forward edge of the second abdominal segment is orange, but the back edge is black. The color on the second segment extends closer to the edge than it did in bimaculatus.

Bombus vagans, which I have seen at Fullersburg but not yet at Mayslake, has the first two abdominal segments yellow all the way to the back edge.

Bombus vagans 1b

That leaves only one species of bumblebee which is said to be common in Illinois but which I have not yet observed: Bombus pensylvanicus (listed in some references as B. americanorum). That one is most similar to B. auricomus, but typically has the top rear part of the thorax black or orange, and the first abdominal segment has some yellow on its rear edge.

Here are some web references. For a really nice diagrammatic comparison of these color patterns you can download a pdf file called “Bumble Bees of Illinois and Missouri”. A site with additional identification and ecological information is the beespotter site.


by Carl Strang

Bumblebees are fascinating insects, and I have much to learn about them. So far I slowly am getting a handle on some of the local species. It happens that they are generally easy to distinguish through their different arrangements of yellow and black fur. I call it fur; it certainly holds in heat generated by their flight muscles, allowing them to range through temperate climates into the Arctic. I remember seeing bumblebees on my study area in western Alaska. In our area the most common species may be Bombus impatiens. Here is a queen of that species.

Bombus impatiens queen 2b

Bombus impatiens is marked by the thorax being almost entirely yellow, especially on the sides, and by the black abdomen with only the first segment yellow. The queens are all you see early in the season. Only they survived the winter. By June their much smaller daughters are visiting flowers. I suspect this may be why Solomon’s seal (mentioned yesterday) waits to bloom until now. The tiny faces of bumblebee workers just fit in the suspended flowers of that species. I doubt that a queen could manage it.

Ecological studies of bumblebees emphasize tongue length, with different species subdividing the range of flower sizes accordingly. B. impatiens, being a generalist, has an intermediate tongue length. As I get a handle on the species I will want to learn about this difference and see which bumblebees visit which local flowers. Here is Bombus vagans, which I photographed visiting wingstem at Fullersburg a couple years ago.

Bombus vagans 1b

Note that it has two yellow abdominal segments. It also is larger than impatiens. The next shot illustrates the significance of tongue length.

Bombus vagans 2b

A third species is Bombus fervidus. This one I haven’t caught in action. The photo is of a dead one I found on the trail at Tri-County State Park.

Bombus fervidus 3b

Note the large black area on the thorax and the mostly yellow abdomen. I have seen it at Mayslake, as well. In recent days the picture has become a little clouded as I have found another species at Mayslake that is very close to impatiens, and so needs close study to distinguish it.

Bombus bimaculatus 2b

Bombus bimaculatus has the first abdominal segment yellow plus the central part of the second segment. The feet are yellow, as is a tuft of hairs on the top of the head, barely visible in the next photo.

Bombus bimaculatus 3b

Those last minute features help distinguish it from another species, B. griseocollis, which I have yet to find.

Here is a website with a key to bumblebees of Wisconsin, which I have found helpful in making identifications.

« Older entries

%d bloggers like this: