You are welcome. I'm learning a lot from there too.
The other Garden Patrol parasite of Japanese Beetles, also introduced, is a Tachinid fly:
I. aldrichi overwinters in a puparium within the body of the dead host in the soil. The adult flies appear from mid-June to mid-July in New Jersey and feed on aphid honeydew and nectar. The females attach an egg on the thorax of newly emerged beetles. Each female can deposit up to 100 eggs over a 2 week period. The egg hatches in 24 hours and the maggot burrows into the body cavity of the beetle to feed internally. The larvae kill the beetles in about 5-6 days (compared to the 4-6 week life span of a non-parasitized adult), during which time the beetles bury themselves in the ground.
...it's too late in the season now, but I'm going to look for JBs with eggs on their heads next early summer!
Photos of Japanese Beetles that have been oviposited with eggs of Istocheta aldrichi - Winsome Fly - BugGuide.Net
...ha... Looking at the photos again, strictly speaking, the eggs are not on their heads but on their thoraxes (middle segment between head and abdomen) as described in the article.