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Looking for ants? Sometimes it is only a matter of finding the right plant.

Most people know ants come to the extrafloral nectaries on peony buds and we've talked about sandmat before, but are there any other plants that regularly attract ants?

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The umbel flowers of wild parsnip (Pastinaca sativa) might be a good place to look for different kinds of ants.

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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.

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Ants, flies, wasps and other insects can be readily found visiting the large nectaries of open flowers.

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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?

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Sometimes we get so used to seeing ants visiting extrafloral nectaries, it seems unexpected to see them visiting regular floral nectaries.

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Take this shrubby dogwood flower (probably gray dogwood, Cornus racemosa). The nectaries are the creamy yellow bands at the base of the female part of the flower (the pistil or carpel) in the center.

 

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Formica workers seemed to be visiting the plants most frequently, although other ants were in the area.

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Ants weren't the only insects attracted to the nectaries of the dogwood flowers.

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Along with the usual wasps, flies and bees, there were also more unusual true bugs and beetles.

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A number of the smaller butterflies stopped by, including hairstreaks and blues.

It turns out azure butterflies in particular are attracted to these types of dogwoods and lay their eggs on them. What happens next? Of course, the ants tend the azure caterpillars! Nature Posts blog has an incredible series of photographs and videos of ants tending azure butterfly caterpillars.

Interested in planting a garden for ants or butterflies? You might want to consider planting some of the dogwoods (Cornus sp.)

Have you ever seen azure caterpillars on dogwoods? I am definitely going to be looking from now on.