Well, considering that wasps drink nectar just as bees and other pollinators do, it would make sense that since Angelica is attractive to bees for it's nectar, it would be attractive to other insects that drink nectar as well.
they can make chemicals that attract wasps. the wasps eat the caterpillars. There might be plants that make butterfly repellents, but there would be no way to test for it because butterflies only lay eggs on special host plants and avoid the rest anyway.
If you are trying to attract wasps to an aspen tree there are a few things you can do. You can plant very fragrant flowers or blossoming shrubs around the tree. You can also place fruit trees need your aspen to attract the wasps.
angelica
yes
leaves
Wasps nests themselves do not necessarily have an odor, however dead wasps trapped inside a nest will generate an unpleasant odor and attract other pests.
all sorts of plants attract the hummingbird!
Wasps are useful to the food chain. Wasps eat caterpillars and other insects that destroy crops, as well as pollinate flowers and other plants.
The European species, Angelica archangelica, and the North American species, A. atropurpurea from the genus of plants in the parsley family. Species of Chinese angelica, A. sinensis, A. pubescens, A. dahurica.
Scented candles can attract bees and wasps. These types of candles are made with raw ingredients that the bees feel drawn to.
Wasps eat some smaller insects, which can attack flowers and plants. As a result they are a positive influence in a garden.
to attract insects for cross-pollinationWithout more information on these "pedals" (e.g. what are they part of) this question cannot be answered.