Well, this is more of A=B and B=C therefore A=C kind of thing, but wasps use caterpillars to feed their young and corn earworm is a caterpiller so wasps must eat them too. I can't think of any other reason the wasps are hanging around the corn inspecting each leaf collar. Even yellow-jackets are busy feeding their young until around August. After that, they become nuisance at picnic, BBQ, and campsites.
https://www.eduwebs.org/bugs/yellow_jacket.htm
WESTERN YELLOW JACKET or WASP -- Vespula pennsylvanica
Although there are seventeen species of yellow jackets in North America, the one that people are most likely to have an encounter with in urban areas is the Western Yellow Jacket. Yellow jackets are beneficial because they are pollinators and they feed on a lot of soft-bodied insects such as caterpillars and flies that are often harmful.
Adult wasps are ½ to 3/4 inch long, with characteristic yellow and black stripes and transparent wings. Yellow jackets are often feared for their sting, which is a hazard to people who are allergic. However, they are beneficial as predators of caterpillars, flies and beetle grubs. Nests need not be removed if they are not interfering with the lives of people in the area.
Here's a good photo ID site: https://www.pollinator.com/identify/whatsbuzzin.htm
What's Buzzin' in My Garden?
"I don't know a bee from a wasp, a hornet, or a yellow jacket."
(These are pictures from the eastern USA, your garden may have different species.)
Also from https://www.small-farm-permaculture-and-sustainable-living.com/vegan_pest_control.html
‣ Wasps and hover flies:
There are many species of wasp and hover fly like insects that as adults are nectar feeders, but as larvae are carnivores. Adults in this group will hunt food for their young including caterpillars, spiders, aphids, earwigs, tomato worms and grasshoppers. Encourage them by letting parsley, carrot and fennel flower and having nectar producing native plants near your gardens.
p.s. Silks have come out!
