Bee Goggles

One of the best outcomes from learning a lot about a group of species is that I start to see prairie through their eyes.  That perspective has been really valuable for me and has led me to evaluate, restore, and manage prairies differently.  Over the last couple years, I’ve been learning quite a bit about bees and other pollinators (and dragging you along with me through numerous posts on those species – sorry about that).  As a result, when I look at prairies these days, I sometimes feel like I’m doing so through “bee goggles”.

Stiff goldenrod (Solidago rigida) is done blooming and well into the process of making seed.  It seemed like the blooming window for this and other late summer/early fall species was really short this year.

Stiff goldenrod (Solidago rigida) is done blooming and well into the process of making seed. It seemed like the blooming window for this and other late summer/early fall species was really short this year.

What I’m seeing through my bee goggles these days is that food gets pretty scarce in the fall, and the end of this wildflower season is very near.  Even a couple weeks ago, when Anne Stine and I were doing the last field sampling of bees for her research project (September 18 and 20), it was clear that most plant species were done blooming for the season.  Most goldenrods were finished, as were sunflowers, tall boneset, and just about everything else.  As a result, we didn’t see as many bees as we’d hoped to, and they were very concentrated on the few blooming flowers that were still around.

One group of flowers that was still blooming was the asters.  In fact, heath aster (Aster ericoides) provided, by far, the greatest abundance of flowers we saw during those September bee surveys.  Interestingly, however, even given the scarcity of other flowering plant species, we saw surprisingly few bees using heath aster.  We did, however, see lots of hover flies (Syrphid sp) and quite a few wasps.  Sure, there were a few bees here and there, including some little sweat bees and a few others, but not all that many.  In addition to heath aster, there were two other larger-flowered asters blooming in a few prairies: New England aster (Aster novae-angliae) and panicled aster (Aster lanceolatus).  Both of those seemed to host significantly more bee visitors than did heath aster, and New England aster – though pretty uncommon – was the most attractive of the two.

(For you botanists in the audience: yes, I know the genus of asters has changed, but I refuse to go along with it.  Asters are asters, not Symphyo-whatever.  Sue me.) 

Heath aster was in bloom during our last bee sampling period but seemed to be much more attractive to flies and wasps than to bees.

Heath aster was in bloom during our last bee sampling period but seemed to be much more attractive to flies and wasps than to bees.

Pitcher sage (Salvia azurea) was another late-blooming species that was very attractive, at least to larger bees – as well as butterflies.  However, while we saw scads of bumblebees on pitcher sage during our last bee survey period (August 19-20) we only found a couple this time around.  Because of that, I assume the queens that will initiate next year’s new colonies have mated and are now finding a nice comfy place to spend the winter.  Since producing fertilized queens is the ultimate goal of every bumblebee colony, the rest of the colony members can (and will) die happy, knowing they played their role successfully.

This digger bee (Anthophora walshii) was perched one morning on a stiff sunflower that has finished blooming for the year.  Food is getting scarce...

This digger bee (Anthophora walshii) was perched one morning on a stiff sunflower that has finished blooming for the year. Food is getting scarce…

Interestingly, while looking for bees, we saw some widely scattered blooming plants of goldenrods, annual sunflowers, tall boneset, and a few others – even though the vast majority of plants within those species had long finished flowering.  Some of those plants appeared to have been grazed by cattle or other animals, and so were behind schedule and trying to rush some flowers and seed production before the first freeze.  Others just appeared to be late bloomers – in full flower, surrounded by others of the same species that were already decked out in seed heads.  Maybe they were just a little different genetically?  Regardless, those late individuals were getting abundant attention from bees and other pollinators and were clearly more attractive than heath aster…  As long as they are able to get their seeds ripened before temperatures drop too low, those late blooming flowers should come out pretty well.  As we harvest seed from some of those species this fall, it would be probably be smart for us to gather seeds from those plants that may be genetically inclined to bloom a little later than their counterparts.  Maybe we can create restored prairies with a longer flowering period and give late-season pollinators a little autumn boost.

This moth used pitcher sage as an overnight roost, but this particular plant is done providing nectar for the year.  There are still a few pitcher sage plants blooming here and there, but not many.

This moth used pitcher sage as an overnight roost, but this particular plant is done providing nectar for the year. There are still a few pitcher sage plants blooming here and there, but not many.

I don’t need bee goggles to see that fall has arrived.  Our prairies have mostly turned golden brown, and while the range of colors has narrowed, it has been complemented by an incredible array of seed head architecture that lends grasslands a new texture.  The subtle beauty of autumn prairies will last until next year’s green up starts, but it will be much quieter for a while without bees and the myriad other insects that make summer sound so alive.  However, as with all prairie animals, bees have their own ways of surviving the coming winter, and will emerge from dormancy – along with the rest of the prairie – when the time is right in the spring.

It’ll be good to see them again.

The Softer Side of Wasps

A couple weeks ago, I posted a photo of a wasp (along with some other shots from a walk through one of our wetlands) and mentioned that I’d have a story about that wasp in an upcoming post.  Here you go…

As I was looking for something interesting to photograph on my wetland walk, I noticed this paper wasp (Polistes fuscatus) nectaring on swamp milkweed (Asclepias incarnata).  It was moving slowly enough – and was focused so strongly on nectar – that it was relatively easy to get some photos of it.  In fact, I ended up watching and photographing it for about 10 minutes.

A paper wasp (Polistes fuscatus) feeding on milkweed nectar.

A male paper wasp (Polistes fuscatus) feeding on milkweed nectar.

You may or may not know that most (all?) wasps in our prairies feed on nectar as adults, but feed invertebrates to their offspring.  Many wasps are parasitoids – they capture and paralyze their prey, stuff it into a burrow or other similar structure, and then lay an egg on it.  When the egg hatches, the wasp larva feeds on the paralyzed invertebrate.  Most wasp species specialize in capturing a particular kind of invertebrate; some attack spiders, others go after cicadas, bees, flies, etc.  Parasitoid wasps tend not to be aggressive toward humans, and are (at least most of them?) solitary – just a single female provisioning food for her nest.  The mud dauber is an example of a parasitoid that is often seen in yards.  Their mud tubes often show up on the sides of houses or inside garages.

A mud dauber wasp creates a ball of mud to build her nest.

A black and yellow mud dauber wasp creates a ball of mud she’ll use to build her nest – a mud tube – which she’ll then fill with paralyzed spiders and her eggs.  A second species of mud dauber (irridescent blue/black) doesn’t make her own nest, but instead opens up the mud tubes of the black and yellow dauber, takes out the original eggs, and replaces them with her own!

The paper wasp is a little different.  Paper wasps are social, and their familiar hanging nests are initiated each spring by a fertilized queen.  Often, the queen will be joined by other females who help build the nest and feed the young.  However, any eggs laid by those other females are eaten by the queen, ensuring her dominance.  As the nest grows, multiple generations of wasps are produced, some of which become aggressive defenders of the nest – and that’s when the trouble starts for those of us who host paper wasps on our front porches.

Another difference between paper wasps and parasitoid wasps is that paper wasps catch and kill their prey (often caterpillars) rather than just paralyzing it.  In fact, after they kill a caterpillar, they’ll feed chunks of it to their older larvae and then give prechewed pieces to younger larvae.  You can read much more about paper wasps at this wonderful site from the University of Michigan.  In addition, here is a link to a short YouTube video with fantastic footage of paper wasps.

Returning to the wasp I was photographing in our wetland…

As I watched the wasp, I noticed that his feet were starting to accumulate quite a few sticky pollinia from the milkweed flowers.  Some of you who have been reading this blog for a while might remember a previous post that detailed the unlikely, but fascinating process of milkweed pollination.  Essentially, the process relies on an insect accidentally sticking its foot into one flower, pulling out a pollinia (a sticky packet of pollen), and then stepping into another flower and losing the pollinia as it pulls its foot back out.  Everything has to work just right for pollination to occur, and it seems as if it would hardly ever work, but the number of milkweed pods each fall are evidence to the contrary…

The same wasp a few minutes later, with multiple pollinia attached to its feet.

The same wasp as above, with multiple pollinia attached to its feet.  The pollinia are the yellow globs at the tips of its legs.

After the wasp accumulated a number of pollinia, it stopped feeding and started trying to remove the pollinia by running its legs through its mouth.  I couldn’t tell if it was eating the pollinia or just removing them.  Either way, it worked at it for quite a while, and it still didn’t get them all of (a good thing for the milkweed plant!)

The wasp trying to remove the pollinia from its feet (to eat?  because they're irritating? I don't know...)

The wasp trying to remove the pollinia from its feet (to eat? because they’re irritating? I don’t know…)

Wasps are common visitors to flowers, but in many cases are less effective pollinators than fuzzy bees that get coated with pollen. However, as I’ve been paying particular attention to bees and other pollinators during the last several weeks, I have seen numerous wasp species on milkweed flowers.  That probably works out pretty well for the milkweeds, since all they really need is a creature that steps into multiple flowers as it crawls around.

Paper wasps are not among most people’s favorite insects, and for good reason.  Many of us have been stung by the aggressive defenders of a paper wasp nest.  On the other hand, those stinging wasps are just defending their nest and queen – a noble and virtuous act, and something that’s hard to blame them too much for.  Regardless, it’s also nice to see a paper wasp doing something that contributes to the greater good, like pollinating a milkweed plant.  When I’m out taking photos of fluffy white milkweed seeds later this fall, I’ll be sure to mentally thank the paper wasp for a job well done.