William Keckler explains:
This applies to June bugs, Japanese beetles, ladybugs and the like as
well. Hierophants seem divided on whether or not this applies to the
lightning bug. Better safe than sorry, I always say. Curses resulting
from Scarab-Slighting can have quite gruesome sequelae.
An ancient Egyptian blessing should also be spoken. A good one would be...
"I bless your Carapace; I bless your Undercarriage; I bless your Antennae*; I bless your Many Legs; I bless your Tympanic Membrane; I bless you and Pray you will take Good Report of me to the Underworld." (Here you may ask for something which resembles the beetle in form. Hint: Blu-ray players have a carapace too!)
*I am substituting "Antennae" for the sake of North American probability. If it is indeed a genuine Egyptian scarab, you can substitute "Pincers."