Asked June 01, 2015, 9:34 PM EDT
Macomb County Michigan
Unfortunately, without pictures or a better description of both the insects and the cocoons, I can only give you some suggestions as to what they might be. One possibility is that the insects are digger wasps.
This site shows many of the wasps we have here in Michigan. Do your wasps look like any of these? http://insects.ummz.lsa.umich.edu/fauna/vespidae.html
As for the “cocoons”, they could be the pupae of sphinx moths or hornworms. Do the pupae “wiggle”? What size and color are they? Do they look anything like the ones at this site: http://msue.anr.msu.edu/news/hornworm_caterpillars_the_big_cats_of_the_vineyard
Can you send me more information such as the size of the wasp-like insect, and color pattern on the abdomen, do they have white tips on their antennae, are they hairy or smooth?
I assume you do not have pictures, but if you do, they would certainly help.
Before we would know how to control them, or if it would be necessary, depends on their identification. If the “wasps” are not aggressive, you might try to work around them. Wasps are beneficial as they are good pollinators, and many capture insect pests for food.
If you could, please respond back to me with more information. I am curious myself as to what these are.
Thanks for sending this to “Ask An Expert”.