Cranberries, crawling with farmer ants

When I was a kid, my grandma Nordvick would take us to pick wild cranberries in a woods a short distance from our house in northern Minnesota. The berries grew on small tree or shrub like trees.

I’d eat some, pick some and mostly play. The berries are extremely tart and filled up almost entirely with one white pit. We’d take buckets of berries home, squeeze out the juice, add a ton of sugar and make pancake syrup. Grandma told and retold the story of the time a black bear found their buckets of berries and gorged itself before they got the berries home.

A couple weeks ago, I was lucky enough to stumble upon some cranberries while outside with my daughter. It was fun to share memories of picking the berries as a kid and watch her face pucker up as she tasted them. Even though they are sour, she ate quite a few!
But first I used my inaturalist app and Google to identify them, just to be sure. We always talk about safety when foraging and never, ever put anything into our mouths unless we are sure.
I determined the berries I’ve called cranberries all my life are cranberry viburnum, or highbush cranberries, (1.) and they are a member of the honeysuckle family.

They aren’t actually a true member of the cranberry family. When we were in Alaska, we learned about lowbush cranberries (2.), which is different.

While my daughter was chowing down, I noticed something interesting. Some of the clumps of berries were absolutely crawling with ants.

At first I assumed they were sucking the juice of the berries but then I remembered ants typically climb plants to farm aphids. Sure enough, when I looked closely I could see that’s what was happening.
The aphids excrete a sugary substance the ants eat (I didn’t find any sources that said *where they excrete it from) and in turn the ants control and protect them from predators. (3.) I found one really interesting article about a giant aphid farmed by ants in Britain. These aphids hadn’t been seen before and were spotted by a naturalist and photographer, who was looking for a different type of bug to photograph. What fun that would be, to help entomologists learn more about a new species of insect? (4.)

I certainly didn’t find any new species. These were just common, everyday cranberries, ants and aphids. But that didn’t stop me from thoroughly enjoying spotting and photographing them.

Sources:

(1.) https://trees.umn.edu/highbush-cranberry-viburnum-opulus

(2.) https://www.alaska.org/advice/low-bush-cranberry

(3.) https://www.sciencedaily.com/releases/2007/10/071009212548.htm

(4.) https://www.theguardian.com/environment/2020/jan/24/ants-run-secret-farms-on-english-oak-trees-photographer-discovers