This week’s crawly reminds us to never judge a beetle by its cover. Meet the ashy-gray lady beetle (Olla v-nigrum).
Our first fun fact – ashy-grays come in two forms: the pictured form which gives them their moniker and a black form which gives them their scientific name “nigrum” which means “black” in Latin and the “v” stands for “variation”. The black form of the ashy-gray also sports two red dots, one on each elytra (wing cover).
While ashy-grays are native lady beetles and can be found across most of the United States (from Oregon’s latitude south), there are not a lot of sightings of them recorded for our area. Some people may not recognize the ashy-grays as lady beetles, but more likely people just don’t get a chance to see this small (just under one-quarter of an inch) lady beetles because usually they live in trees (arboreal).
Ashy-grays like willow trees, so keep an eye out for them there. The pictured beetle was snoozing on a blackberry leaf, so they do come down out of the trees as well.
In both nymph and adult form ashy-grays dine mainly on aphids and psyllids.
While we’re on the topic of lady beetle dining habits, let’s take a quick look at the West Coast history of “lady beetles as pest control”.
In the late 1800s California citrus orchards were in trouble from an infestation of cottony cushion scale insects which had been accidentally imported from Australia. To resolve the issue, vedalia lady beetles were intentionally imported from Australia and the citrus industry was saved in less than one growing season.
That was the start of the science of biological control, using a non-native predatory insect to control a nonnative pest insect.
If it seems impossible lady beetles could save citrus in such a short time period, consider that as larvae lady beetles will munch down 350 aphids (or their prey food of choice) before they morph into adults.
As adults lady beetles will eat up to 5,000 aphids, psyllids, mealybugs, etc. in their lifetime.
That said, don’t run out to buy lady beetles in bulk for your yard. Typically, the species sold en masse are convergent lady beetles (Hippodamia convergens) because they congregate into large overwintering populations in the Sierras, so they’re easy to “harvest” and sell.
However, most of them will disperse quickly when freed in your yard and won’t even grab a snack for the road. This is because they already stored up on sugar for the winter and don’t need a meal.
Your better bet is to make your yard appealing to the wide variety of lady beetles that live in our area. It’s even better to have several species, because many species of lady beetles are specialist feeders.
How do you put out the proverbial “welcome” sign?
Provide a good late summer/fall diet and winter shelter in your yard. This means planting some late blooming flowers so the beetles have a source of nectar if they’ve chowed down on all your aphids.
For cover, they like to overwinter under leaf litter and around the bases of perennial grasses and ground covers, so don’t blow all those leaves out of your yard. Leave some (a firewise distance from structures!) for the lady beetles and other critters to snooze in when the temperatures drop. Follow these easy steps to keep nature’s pest controllers in your yard year-round for years.
