Finds Along the Way

by Carl Strang

It has been a full and busy field season, so full that I have neglected the blog, for which I apologize. Today I begin to catch up. There will be a series of posts on this year’s singing insects research, but for now I will share a few side observations made along the way. The best of these was my first jumping mouse.

Meadow jumping mouse

This little rodent is widely distributed in the region but seldom seen. I went well into my 69th year before I finally saw this, my first one. It was smaller than they are supposed to get, so I assume it was a youngster whose naivete made it possible for me to watch him. Still, he was shy enough that the above photo was the best I could get. If you enlarge it for a better look, note the very long tail which trails off the right margin. Also, look beneath his (I say his, don’t know the gender) belly at the very large hind foot sticking out. I admired his beautiful golden coat as he hopped among the plants on those hind feet, nibbling here and there.

I fit some monitoring walks at St. James Farm into my summer. On one of them I ran across a perched wandering glider.

Wandering gliders usually are seen only in flight, distinctive in being large yellow dragonflies with chestnut brown heads.

This species has a worldwide distribution, and routinely crosses oceans. I remember seeing one in Australia.

Earlier in the season at St. James Farm I saw a queen bumble bee with a striking color pattern.

The black-and-gold bumble bee has yellow hairs on top of its head, which allow separation from the similar Bombus pensylvanicus.

Even more special was a summer sighting of a rusty-patched bumble bee.

This one is distinguished by a reddish area surrounded by yellow at the base of the abdomen.

The full pollen baskets and wild bergamot host speak to the bee’s focus that day, as well as the time of the season.

This was special, because the rusty-patched bumble bee is a federally endangered species. Fortunately, it was on protected public land, and of course I reported it to the owning agency.

Recent Photos

by Carl Strang

Time to bring out a backlog of photos from the first half of August. First, a couple bumble bees from my last day on the job at Mayslake Forest Preserve.

This Bombus auricomus was huge, practically dwarfing the carpenter bees working nearby. She must have been a new queen, stocking up for her long winter wait.

This Bombus auricomus was huge, practically dwarfing the carpenter bees working nearby. She must have been a new queen, stocking up for her long winter wait.

Nearby, this yellow bumble bee Bombus fervidus also worked the wild bergamot.

Nearby, this yellow bumble bee Bombus fervidus also worked the wild bergamot.

The remaining photos are from a few days’ bouncing around in singing insect surveys.

This oblong-winged katydid peeked out through a hole in the vegetation in the late dusk at Midewin National Tallgrass Prairie.

This oblong-winged katydid peeked out through a hole in the vegetation in the late dusk at Midewin National Tallgrass Prairie.

This mottled sand grasshopper at Kankakee Sands was my first for Newton County, Indiana.

This mottled sand grasshopper at Kankakee Sands was my first for Newton County, Indiana.

Female Carolina ground crickets are distinctive with their short ovipositors. This one posed at Subat Forest Preserve, Kendall County.

Female Carolina ground crickets are distinctive with their short ovipositors. This one posed at Subat Forest Preserve, Kendall County.

Playing Catch-up 1

by Carl Strang

Photographs have been accumulating in the blog file, but the inspiration to tie them together sensibly hasn’t come, so this week I will simply empty the file out. These all are from Mayslake Forest Preserve, and today’s collection is a miscellaneous one.

We’ve had more rain than usual this far into the summer. Here some fresh mud captured a set of chipmunk tracks.

We’ve had more rain than usual this far into the summer. Here some fresh mud captured a set of chipmunk tracks.

The parking lot marsh surprised me last week with an array of a plant new to the preserve. This is an aquatic buttercup, the yellow water crowfoot.

The parking lot marsh surprised me last week with an array of a plant new to the preserve. This is an aquatic buttercup, the yellow water crowfoot.

This has been a good year at Mayslake for a bumblebee species that varies in numbers considerably between years: Bombus auricomus. The yellow cap on the head, large size, and bold black and yellow pattern are distinctive.

This has been a good year at Mayslake for a bumblebee species that varies in numbers considerably between years: Bombus auricomus. The yellow cap on the head, large size, and bold black and yellow pattern are distinctive.

Queen Anne’s lace is blooming, and on Friday it pointed me to two arthropods new to the Mayslake list. This one has a name I like: Strangalia luteicornis. It is a woods-edge long-horned beetle whose larvae bore into woody plants including grape vines.

Queen Anne’s lace is blooming, and on Friday it pointed me to two arthropods new to the Mayslake list. This one has a name I like: Strangalia luteicornis. It is a woods-edge long-horned beetle whose larvae bore into woody plants including grape vines.

Here a northern crab spider, Mecaphesa asperata, feasts on a flower-visitor fooled by the spider’s camo.

Here a northern crab spider, Mecaphesa asperata, feasts on a flower-visitor fooled by the spider’s camo.

June Insect Phenology

by Carl Strang

As I described in the previous post, plant phenology this year has been marching along in its usual pattern of between-year convergence of first flower dates. The results for insects in June were less consistent, and therefore more interesting. First appearance dates of 17 insect species in June were a median 11 days later in 2013 than in 2012. This is not surprising, given last year’s early season. There was some convergence, as that difference was 33 days in May.

The first sighting of Bombus auricomus at Mayslake Forest Preserve was on June 14 this year.

The first sighting of Bombus auricomus at Mayslake Forest Preserve was on June 14 this year.

No such convergence appeared in the comparisons of 2013 with 2011 and 2010, where the June median was 11 days later this year than in 2011 (19 species), and 9 days later than in 2010 (19 species). The differences in May were 10 days in each case, so no change. The median showed no difference (0 days) between June first appearances in 2013 and 2009 (19 species); in May that difference was 5 days.

The first monarch butterfly arrived from the South on June 13 (and yes, this is a photo from an earlier year).

The first monarch butterfly arrived from the South on June 13 (and yes, this is a photo from an earlier year).

We had some warm weather, but on the whole this spring was cool and often rainy. I think that weather pattern probably accounts for 2013’s continued lateness through June, and the relative lack of convergence to date.

Mayslake Insects Update

by Carl Strang

We’re at the edge of summer, and bees and butterflies and Odonata are center stage. Skippers have been appearing at flowers.

Earlier in the season there were wild indigo dusky wings. This is one of the skippers that typically rest with wings open.

Earlier in the season there were wild indigo dusky wings. This is one of the skippers that typically rest with wings open.

This week a new skipper appeared in Mayslake’s main prairie. This is one that closes the wings at least part way, and had practically no detail beneath.

This week a new skipper appeared in Mayslake’s main prairie. This is one that closes the wings at least part way, and had practically no detail beneath.

With the wings partly open there clearly is some color on the leading edge of the forewing, and small groups of dots. It appears to be a tawny-edged skipper.

With the wings partly open there clearly is some color on the leading edge of the forewing, and small groups of dots. It appears to be a tawny-edged skipper.

Carolina saddlebags have been one of our more consistent early season dragonflies.

The violet forehead is just visible in this back-lit individual.

The violet forehead is just visible in this back-lit individual.

So far the only spreadwing damselflies I have seen have been slender spreadwings.

Slender spreadwings continue to be common this week.

Slender spreadwings continue to be common this week.

In the past few days a number of dragonflies have made their first appearances of the season.

One of the recent species is the eastern amberwing. I like the way the light projects a distorted image of this male’s wings onto the rock.

One of the recent species is the eastern amberwing. I like the way the light projects a distorted image of this male’s wings onto the rock.

Early bumblebee colonies have begun sending out workers.

This bee was diving into the foxglove beard tongue flowers so quickly upon landing that flight photos were needed to show sufficient detail for identification. The black basal abdominal segment followed by two yellow ones is one clue. The trace of yellow on the back half of the dorsal thorax is another.

This bee was diving into the foxglove beard tongue flowers so quickly upon landing that flight photos were needed to show sufficient detail for identification. The black basal abdominal segment followed by two yellow ones is one clue. The trace of yellow on the back half of the dorsal thorax is another.

The other details are consistent with an identification of Bombus auricomus.

The other details are consistent with an identification of Bombus auricomus.

New insects will be emerging frequently for the next couple of months.

Insect Catch-Up

by Carl Strang

I consider photos to be an indispensible part of this blog. Blogs are based on writing, but in a visual medium like a computer screen, I believe images are needed as well. I try to get photos of everything new I encounter in the field, and edit and copy selected ones into a file I keep for the blog. They then are the basis for new posts. Sometimes there are orphan photos, ones which by themselves may not be enough for an entire entry. Today I want to clear out three such photos of insects. The first goes back to mid-June.

Unicorn clubtail on May’s Lake

I had been seeing a few jade clubtails at Mayslake Forest Preserve, perched on shore or occasionally on floating algae, but then on June 16 there was an odd-looking individual that clearly was a new species for the preserve list. The photo made clear that this was a unicorn clubtail, a species in the same genus as the jade clubtail, common in some places but not, in my experience at least, in DuPage County.

Reversed haploa, a member of the tiger moth family

This was a big year for reversed haploas. Usually I see 5 or so in a season, but I saw dozens at Mayslake in the first half of July.

Bombus pensylvanicus. I think.

There are two species of bumblebees in northern Illinois that are so similar I cannot distinguish them confidently. From what I have seen in internet sources, I am not alone in this. Both have large areas of black on the thorax and large areas of yellow on the abdomen. There are variations in “fur” color on the head and posterior thorax that bring enough overlap into the picture to confound the identification of individuals. As far as I can tell, it comes down to the color of the basal abdominal segments. Less black and more yellow indicates pensylvanicus, more black and less yellow indicates Bombus auricomus. In my limited experience, though, there appears to be another possible indicator. B. auricomus seem to be brighter, the yellow and black so sharp as to really stand out, while the colors are duller in pensylvanicus.

Here is an auricomus from an earlier year

If any readers can lend insight on this, I would appreciate a comment to that affect.

Bumblebee Dynamics

by Carl Strang

In my last update on bumblebees  at Mayslake Forest Preserve I described the 5 species I had observed to that point. In the subsequent few weeks there have been a couple of changes to report. First is the apparent addition of a 6th species.

Bombus pennsylvanicus 1b

I believe this to be Bombus pennsylvanicus. At first glance it is very close to Bombus auricomus, which I described earlier. Both are relatively large bumblebees, both have lots of black on the thorax (especially on the sides), and both have segments 2 and 3 of the abdomen all yellow. However, auricomus has a cleaner, sharper look. All the yellow areas are bright, pure yellow. The black areas are unblemished by hairs of other colors. Both black and yellow areas are sharply defined, and correspond to the edges of body segments. If I am correct in my identification, pennsylvanicus has a muddier look. The yellow of the dorsal abdomen spills a little onto the first segment as you can just see in the above photo. Also, the yellow area of the posterior dorsal thorax has some black hairs mixed in, and the black on the sides of the thorax has some yellow hairs mixed in.

The more astonishing change is the nearly total disappearance of Bombus bimaculatus over the past three weeks. Through July, this was the most common bumblebee at Mayslake, with numbers exceeding those of all other species combined. I was away a week for Roger Raccoon Club , and returned to find the bimaculatus nearly gone. Now I see at most one or two a day. The other common small species, Bombus impatiens, continues essentially unchanged.

Bombus impatiens worker b

This is my first year of following the bumblebees at Mayslake. I don’t know if this disappearance is usual, and I don’t know what it means. I doubt that the species has a limited season, as bumblebees generally continue through the summer. Some of the native, solitary bees are specific to a single flower species and thus have defined seasons, but bumblebees are generalists. They are known to monitor changes in flower abundance and to travel miles, and so may have abandoned Mayslake for an abundant appearance of other flowers elsewhere. Disease might have impacted one colony, but for all the local colonies to be affected with no obvious change in other species seems unlikely (though the uncommon Bombus griseocollis also has been absent in August).

One day earlier this week I saw a couple odd looking bumblebees that seemed clumsy on the flowers.

Bombus bimaculatus or griseocollis male b

Their markings were like those of griseocollis or bimaculatus, not precisely fitting either. They had enormous eyes, and were larger than most workers of either species. Photos showed them also to have unusually long antennae. These are males. What, if anything, their sudden appearance has to do with the absence of their species’ workers is another piece of the puzzle that needs fitting.

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.

%d bloggers like this: