Ominous backyard bugs identified

I first noticed these strange gray bugs with orange spots crawling on the railroad ties we bought to build the retaining wall. In the weeks since, I've noticed more of them. And this morning I looked around and in the dirt, on the retaining wall -- anywhere I looked -- if I saw movement, I saw one of these bugs.
My worry about the bugs had been brewing for a few weeks, but out of denial and laziness I hadn't done anything about them yet. I really didn't want to put a bunch of chemicals in my yard or call exterminators to tent the house... But the sheer numbers of these stupid bugs forced some action. I marched inside and told the loved one that I think the railroad ties came with termites. How many? he asks. Where are they? How big are they? Eventually he agreed to walk down the hillside to take a peek. He had seen termites before, and was pretty sure these bugs were too big to be termites. But they really were everywhere, which partially alarmed even him, so we hit internet. The identification flow charts and insect photo sites did not help. After about 15 minutes our hunger exceeded the need to find the bugs and went out for lunch and errands. One of the stops was to the shopping center that has a bookstore. The first insect field guide did not have anything that looked like my problematic bug.
The second book, however had the answer. It showed photos of insects in several stages of life. They had a photo the same exact larvae that were crawling all over my yard. Hippodamia convergens. The convergent lady beetle. My yard is a ladybug baby making factory!