They are a widespread group, Brian, and appear in many forms. Probably under a lot of local names as well. Those which we see here are Cassida species, but the overall common name is Tortoise Beetles. They come under the Chrysomelidae (Leaf Beetles) general heading.
The trouble with common names is that they get used differently in different countries.
Definitely a leaf beetle. But with 35,000 different species it might take a while to nail the name.
Here, some people are terrified about 'Black Widow Spiders' which are very loosely related to the real Black Widows and can give a slight bite if handled; but in reality they aren't a problem. Funnel-web Spiders and Huntsman Spiders are two other terms which are incorrectly used here.