Here is a photo of a convergent lady beetle, shown on a flowering broccoli plant. The name "convergent" comes from the two diagonal white lines on their thorax (the part between the head and the wing covers).These beetles are native to California, and help quite a bit with pest control in our gardens. I never buy them, because they just show up hungry every year. They hibernate in the mountains and fly down our way in spring.
You can encourage lady beetles to find your garden by planting flowers they like. The adult beetles live on nectar and pollen when insects aren't available.They may come for the flowers, then, aphids or other pests start to build up, the beetle is there in your garden, ready to pounce.
It isn't hard to plant flowers lady beetles like, since they include many popular ones, and now is a good time to plant most of them. They like cosmos (especially white ones), coreopsis, sunflower, oleander, sweet alyssum, goldenrod, and tansy. I have also see them enjoying the flowers of African blue basil.
Watch for the little alligator-like lady beetle larvae too. They're charcoal gray with orange markings. If you see them, you know the lady beetles are breeding in your garden. And this is good, because the larvae can eat 100 aphids in an hour, compared to the 100 a day an adult lady beetle can eat. Big difference!