Are ladybugs poisonous to cats? As far as I know, my cats have not eaten any ladybugs yet. But I just discovered a ladybug community around my windows inside my house. I am trying to get rid of them, but my main concern is if they can harm my cats if they were to eat one?
The good news is that ladybugs are generally non-toxic but taste bad. (most red, yellow, or brightly colored insects have some sort of toxin or foul taste as a defensive weapon, so you are right to be concerned)
I researched this question further for you through the Animal Poison Control Center, and there is the possibility if the lady bugs are consumed in very large quantities for stomach upset and even ulceration and impaction. However, this would take a very large quantity. I could only find 1 paper referencing a single incident in a dog.
Most cats will develop an aversion to ladybugs after tasting them.
Please be cautious with your chemical treatment, as you know, and use an exterminator that has pet-friendly products, or remove the cats from the household until it is safe for them to return - I'm more concerned about the treatment then the potential for ingestion.
Best of luck, and please let me know if you have any more questions.