Finally feels like spring in 2018

Ahh spring!  Spring of 2018 has had a rough start.  One nice warm day gets the wildflowers going then three cold days set everything back.  So things are coming along...just slower than usual.  I finally had a sunny day to take a few minutes to look for some bees.  My main goal was to find oligolectic bees associated with particular plants (see past post on oligolectic bees). 
I stopped at a big tree plum, Prunus mexicana, since it was full of flowers and many insects flying around.  Below are some interesting finds beginning with the emerald green colored Augochlora bee.

A bee, Augochlora sp. on big tree plum.



Many bees were visiting the sweet smelling flowers of the big tree plum.  It seemed to be a favorite of many bees, flies and butterflies.  Even the massive (comparatively) Eastern carpenter bee was enjoying this nectar.

Carpenter bee, Xylocopa sp., also enjoying the nectar of the big tree plum.

At last, I spotted what I believe to be an long-horned bee, Eucerni tribe, or Osmia sp.on this plant (to be determined).  Many of the Eucerna and Osmia genera are bees that come out in spring.

A bee, possible Eucerna sp. (to be determined) on big tree plum.

While photographing these bees I noticed a possible Andrena species posed in an unusual position and remaining uncharacteristically still.

Possible Andrena bee sitting in a peculiar position.

I figured something else must be keeping this bee in such a position, and sure enough there was.  Blending in to the pinkish base of the flowers was an ambush bug, Phymata sp.  This ambush bug, a kind of assassin bug, hides among flowers and grabs prey as it flies in.  It then sticks its long straw-like mouthpart (proboscis) into the exoskeleton of the prey and sucks out the juicy innards.

Ambush bug feeding on bee.  Notice the yellowish  proboscis mouth part holding up the bee.

While watching this spring drama I noticed a bee flying to a common blue violet, Viola sororia, at my feet. I remembered there was an Andrena violae which only feeds or collects pollen on violets.  I do not have this bee listed for the preserve, and hopefully after tedious microscopic keying of bee body parts, this will be a new species for the preserve.


Possible Andrena violae, oligolectic on Violets.

While laying on the ground photographing the bees visiting Violets I noticed an odd white shape in the grass.  I had to get real close for my brain to explain to my eyes what I was seeing.  The visual mystery was two falcate orangetips mating on the top of a bittercress.  If you look closely you can see the two touching abdomen tips between their wings.  When finished mating the female will lay her eggs on this cress, or another plant of the mustard family, which their caterpillar feeds upon.




Mating falcate orangetips, Anthocharis midea annikae.  You can see the hook to the tip of the wing (falcate).

When not mating, these butterflies rarely sit still very long.  They seem to hit flowers quickly for a taste and move right along.  It was tough to find a male falcate orangetip that would sit still long enough to get a picture of its orange patch.  But after much crawling around on hands and knees one finally sat still long enough to get a shot.  The females lack the orange coloration on the dorsal side of the forewing.

A male falcate orangetip, displaying why the name fits.

It's wonderful how a twenty minute search for bees on a flowering tree can produce many interesting encounters, Ahh spring!

Posted by: Mark Zloba


Oligolectic bees

The Edge staff, along with eager students were lucky enough to spend a week with bee expert, Mike Arduser and his wife Jane.  Mike was here to teach a class on bee identification.  What an incredible and patient teacher Mike proved to be as bee's are not an easy subject to identify.  Now that he is gone, we are finding that more than his friendliness will be missed.  We are also missing his knowledge of bees, bee anatomy and the plants they feed upon.



Bombus sp. on Virginia bluebells, Mertensia virginiana  (not an oligolectic species)



Our brains were filled and tested during the week, but one thing I will always remember and share

with you is that some bees are oligolectic.  I know it's a bit of a glossa twister (bees tongues are called glossa), but oligolectic bees are pollinator specialists on specific plants.  Many bees will pollinate a large host of plants, but some only visit one specific plant, and you need to find that plant if you want to find that bee.  In fact, during the class, Mike collected one of the oligolectic bees for us.  White trout lilys, Erythronium albidum, were blooming during the class and it turns out there is a bee called Andrena erythronii that specializes on this plant.

Erythronium albidum, white trout lily

 

Andrena erythronii, the trout lily andrena

Mike gave us a list of oligolectic bees and the plants they pollinate.  This week we have been going out and watching some of these plants as they slowly start to bloom and await the bees.  Chris Bedel, Preserve Director,  picked up this bee shown below from a spring beauty, Claytonia virginica.  Using the dichotomous keys Mike provided us, I believe it is the spring beauty bee called Andrena erigeniae. 

Spring beauty, Claytonia virginica (photo by Robyn Wright-Strauss) 

Andrena erigeniae, the spring beauty andrena



Our quest will continue to find bees off plants that we know are oligolectic bee hosts.    One thing to remember is that a bee that is not oligolectic may also visit some of these plants.  But an oligolectic bee will only visit it's host plant.   For example, other bee species might visit a spring beauty, but the spring beauty andrena bee will only visit spring beauties.  So you still may need to research the bee and make sure it looks like the one you are looking for. 

Here are a four common spring flowers to watch for that have oligolectic bee associations:

On Packera sp. (formerly Scenicio) (golden ragworts) watch for Andrena gardineri.

On Cornus sp., dogwoods, look for Andrena fragilis. (photo by Robyn Wright-Strauss)

On Viola sp., violets, watch for Andrena violae.

On Geranium maculatum, wild geranium, watch for Andrena distans.

Most exciting so far was learning there is an oligolectic bee on one of the preserve's rare state listed plants.  Nothoscordum bivalve, false garlic or crow-poison, is threatened in Ohio and only found in small patches in 2, maybe 3 Ohio counties.  Waiting for the flowers to open this week, myself and Robyn Wright-Strauss searched a roadside of false garlic for pollinating bees.  Within minutes of searching,  we caught a couple of these small Andrena bees.  Most certainly the first found and caught in Ohio, these were the oligolectic bees called Andrena nothoscordi.  This find is a range extension northward for this species.  All these years this rare plant has been growing roadside in the southern parts of the preserve, but who knew there was a bee associated with it, which is equally as rare.



On false garlic, Nothoscordum bivalve, watch for Andrena nothoscori

Andrena nothoscordi feeding on Nothoscordum bivalve, false garlic

Close up of Andrena nothoscordi (photo by Robyn Wright-Strauss)

Bees can be challenging to identify, but if you know the plant it is feeding on, it can make the task a little bit easier.  This seems to be another good reason to promote the diversity of native plants in your area.   There just might be a native bee relying on them for survival.

To see a list of more oligolectic bees and their host plants, use this link:

http://illinoiswildflowers.info/flower_insects/files/oligoleges.htm

Posted by:  Mark Zloba