Plant-Insect-Insect Interaction: Ants tending aphids on a roughleaf dogwood

Ants (Hymenoptera: Formicidae) congregating on a roughleaf dogwood (Cornus drummondii, Cornaceae). Photographed 06/18/2011 near Blissfield Michigan.

I was recently examining a young roughleaf dogwood (Cornus drummondii, Cornaceae) and I noticed there were a lot of ants (Hymenoptera:  Formicidae) congregating in clusters all over the plant.  A closer look revealed the ants were gathered around groups of aphid nymphs (Hemiptera:  Aphididae) that were feeding on the shrub:

Ants (Hymenoptera: Formicidae) tending aphid nymphs (Hemiptera: Aphididae) on a roughleaf dogwood (Cornus drummondii, Cornaceae). Photographed 06/18/2011 near Blissfield Michigan.

The ants weren’t feeding on the aphids.  Instead, they were feeding on a waste product aphids produce called honeydew.  This substance is excreted from the anuses of the aphids, and it contains not only wastes but also sugary plant sap.  Aphids ingest more sap than they can digest, and the excess is excreted along with their body wastes.

Aphid nymphs (Hemiptera: Aphididae) on a roughleaf dogwood (Cornus drummondii, Cornaceae). Photographed 06/18/2011 near Blissfield Michigan.

Many ants love honeydew and some will tend to aphids to protect this food source.  Some herd aphids like cattle, defending them from predators, protecting eggs in their nests, and carrying nymphs and adults to more productive plant hosts.  The ants can even rub the aphids with their antennae to make them release honeydew, effectively “milking” them.  The individuals shown here seemed to be engaged in that behavior.

The relationship between many ants and aphids is a common example of a mutualism.  This type of symbiosis is to the benefit of both parties.  Ants gain a steady food supply, and aphids gain protection from harm.

Advertisements

About Jeremy Sell

Science and nature nerd.
This entry was posted in Botany, Ecology, Entomology, Organism Interactions and tagged , , . Bookmark the permalink.

One Response to Plant-Insect-Insect Interaction: Ants tending aphids on a roughleaf dogwood

  1. Thanks for the pictures and accompanying text. I wish I had your botanical background. At

    http://wordconnections.wordpress.com/2010/10/22/afido/

    I managed to sneak into my language blog a photo of an ant and aphids on Baccharis neglecta here in Austin last fall.

    More recently, at

    http://portraitsofwildflowers.wordpress.com

    I started a nature photo blog for the flora (and a few critters) of central Texas, if you’d like to see some the plants that grow here natively, which are the only ones I depict.

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s