That happens to me when I use make needs static when I'm a witch as well. I understand you can still cast spells though.
Red assassin beetles are found in China. You will need to go to China and find them.
On this page are maps of where insects and other collectables are found in all three of the 3 holiday locations of world adventures. I believe that the China map may show the locations of the red assassin beetles when you are there if you still have that opportunity active.
An alternative is that cats can hunt for insects as well as reptiles, birds, fish and rodents. They need to be a fairly high level in their hunting skill, I believe. Keep in mind that Red assassin beetles are rare, and won't appear as often as the common/uncommon insects.
