A friend sent me this photograph of an ants' nest in a sidewalk.
What do you think they're trying to say?
Looking for ants? Sometimes it is only a matter of finding the right plant.
The umbel flowers of wild parsnip (Pastinaca sativa) might be a good place to look for different kinds of ants.
Wild parsnip grows in wet areas, such as along creeks or streams. It can also be found growing on roadsides. At four to five feet tall, the flowers are right at eye level for many people. Be careful when visiting the plant, however, because contact with the sap can cause burns to the skin when exposed to sunlight.
Ants, flies, wasps and other insects can be readily found visiting the large nectaries of open flowers.
Although these particular ants were fairly small, large ants such as Formica and Camponotus were also seen on wild parsnip flowers.
What are the ants doing on the plants besides collecting nectar? Wild parsnips are considered to be invasive weeds in many areas. Therefore, ants feeding on nectar might considered to be favorable if they interfere with the plants' success or might be unfavorable if the ants protect the plants from herbivores. Jing Yang and Dana Dudle from the Biology Department at DePauw University studied the effects of ants on the reproductive success of wild parsnip by excluding flying versus crawling insects from certain flowers. In their limited investigation they found no differences in plant fitness whether ants were present or not, but suggested further studies needed to be done.
Regardless, if you are interested in watching ants you should keep your eye out for wild parsnip flowers.
Ave you ever seen ants on wild parsnip?
When you are searching for ants, what plants do you look for?
Last time we discussed how certain species of ants can swim. Even if they can't swim, some species are able to withstand temporary floods by grouping together to form living rafts to float on the water.
Although there has been a rash of papers about the ability of fire ants to form rafts, Jessica Purcell, assistant professor of entomology at The University of California, Riverside, has been studying the ability to float by Alpine silver ants, Forica selysi.
After marking some of the worker ants, the researchers subjected the ants to flooding. They discovered that when the same ants were subjected to flooding a second time, many of them assumed the same positions in the rafts. Rather than coming together randomly, as might be expected during a flooding crisis, the ants were apparently assembling in a somewhat organized fashion.
This video shows the experimental protocol. Note: You probably will want to turn down your computer's sound or hit mute before you click on the play button.
Based solely on this video, I'm going to suggest that painted ants tend to be towards the outside of the raft. Is it possible that damaged ants (painted ants) can assess their health and position themselves at the rim? Of course, that may have happened at random, too. What do you think?
All ants on deck, EurekAlert, AAAS
Purcell J, Avril A, Jaffuel G, Bates S, Chapuisat M (2014) Ant Brood Function as Life Preservers during Floods. PLoS ONE 9(2): e89211. doi:10.1371/journal.pone.0089211