Wednesday, October 1, 2014

Honeydew Rain

The buzzing of flying insects coming from a clump of willows caused me alter course to investigate.  There were hornets moving in and out of the tree canopy, making me think I may be lucky enough to find an active nest.

Once beneath the tree, I could detect minute drops of moisture hitting my face and arms.  It felt as though I was standing in a cool jungle mist, but I knew what it really was and what was responsible.

I was in a rain of honeydew being discharged by colonies of aphids.  As a byproduct of their feeding, these sap sucking insects expel droplets of sweet liquid.

Large aphid colonies can cause a steady downfall of tiny honeydew droplets.  The branches of this willow were almost completely covered by aphids.

Many aphid predators are attracted by the odor of honeydew.  This small fly larva, aka maggot, is the larva of the Aphid Midge, Aphidoletes aphidimyza.  The adult fly feeds on honeydew and lays its eggs among the aphids.  The larvae then consume the aphids.  The larva’s gut takes on the color of the aphid juices being eaten.  This coloration then shows through the transparent body.

Plants growing beneath the willows have been completely covered by honeydew.  The primary buzzing insects were various species of flies feeding on the sugary droplets.  After a while a black mold begins to grow on the leaf.  Shed aphid exoskeletons, dust and other detritus get caught in the sticky mess.  This can’t be a healthy condition for the plants.  Fortunately, massive aphid colonies are a product of late summer and fall, so the plants have already completed their seed production and energy storage.

A variety of fly species was present.  Leaves that hadn’t molded displayed an unnatural shine.  It reminded me of houseplants that have received a coating of liquid wax to make their leaves glow.

Of course, if there’s a sweet liquid to be had, the Yellowjackets will be there to claim their share.  They constantly skimmed over the leaves searching for fresh droppings.  Even when they found one, they paused for only a second to lap it up.

The Bald-faced Hornets foraged higher in the tree and rarely came down to ground level.

The hornets also took the opportunity to grab a live meal.  This guy is subduing a freshly caught fly.  The blue stripe is part of the pattern on the fly’s abdomen.

Several butterfly species were present, dragging their tongues across the leaf surface, sucking up honeydew.

Red-spotted Purple is one of my favorites.  The blue, black and white pattern is quite reminiscent of the colors in a Blue Jay’s feathers.  Quite appropriate coloration for a resident of Blue Jay Barrens.

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