Yucca bugs are fairly common. Here is information about "plant bugs", a category of bugs which includes yucca bugs: https://extension.umd.edu/hgic/plant-bugs-flowers
You can apply insecticidal soap. Read the directions carefully for weather parameters.
Can you be specific about what insecticidal soaps to use. I am unfamiliar with such products. Can you give me a name of a product and where can I find out about weather parameters as you suggested.
Go to a nursery or hardware store and you will find insecticidal soap.
Read and follow the label carefully, and that will tell you the info you need, including the best times to apply based on weather.
Neem oil (Azadirachtin is the active ingredient listed) is also a possibility.