Bees, biomimcry, and butterflies

You know that buzz - that buzz when you walk into a room and the party is in full swing? I heard that buzz recently while stepping onto the bridge over the Arboretum wetland. It made me stop and look for the party. The groundsel bush (Baccharis halimifolia) was in full bloom, hosting the most diverse party of pollinators I've seen in awhile. Many species of butterflies, moths, flies, bees, and wasps, visiting each flower, all very busy collecting nectar and pollen. So busy they didn't even notice the humans walking by!

This busy lady has been visiting long enough to pack her pollen baskets full of tasty, nutritious groundsel pollen. I can hear you - bees carrying baskets full of pollen - this lady is a big fanciful, I think. Well, if you can see the bright orange-yellow circle in the center of the picture, that is actually a pollen basket, a structure bees have on their legs made specifically to hold the collected pollen for the flight back to the hive.

This is an interesting visitor because at first glance you might say it was a bee of some sort when, in fact, it is a fly masquerading as a bee! The telltale in this case is the presence of only one set of wings, which is a characteristic of flies. Bees and most other insects have two sets of wings. Demonstrating an excellent use of biomimicry strategy, these flies gain protection from predators by using a disguise of an insect known to have formidable defenses without having to go to the physical cost of maintaining the venom and stingers of their models, the bees.

For a nice discussion of bees, bee mimics, and how to identify them, you can visit
http://beespotter.mste.illinois.edu/topics/mimics/

I included this last picture because who doesn't like a butterfly picture?

Listen for the party buzz the next time you come to the Adkins Arboretum and see if you can spot a bee mimic while you are here.

Post and photos by Arboretum docent Michelle Dolan Lawrence

A Storm of Acorns

Arboretum staff enjoyed a meeting under the trees this week, narrowly avoiding death by falling acorns. Some of the Arboretum's oaks are enjoying a bumper crop of acorns this year, in stark contrast to last year's nearly non-existent yield.

While acorn production does alternate annually, late spring frost, insect damage, lack of nutrients, and drought conditions can also affect acorn production. Oaks generally begin producing acorns by twenty years of age, but some trees don't produce acorns until fifty years. Just as the canopy of a tree grows over time, so does its production of acorns. By one hundred years of age, acorn production averages out at around 2,200 acorns per tree.

Acorns provide vital nutrients for a variety of birds and mammals, including jays, pigeons, ducks, squirrels, mice, and deer. A correlation between high acorn yields and a rise in Lyme disease has been traced to the acorn-fueled population boom of white-footed mice (pictured), the key host for ticks that carry the disease.

To experience the Arboretum's bumper crop of acorns, acorn enthusiasts have but to exit the Visitor's Center back doors and cross over to the picnic table, which is surrounded by a blanket of the nuts. For those inclined to linger, hard hats are advised.

by Jenny Houghton

Youth Program Coordinator