- Author: Kathy Keatley Garvey
They're back!
Have you checked your rose bushes lately? Along with the lush new growth, you'll probably notice a new crop of aphids. And if you look closely, probably lady beetles (aka ladybugs).
The UC Integrated Pest Management Program (UC IPM) defines aphids as "small, soft-bodied insects with long slender mouthparts that they use to pierce stems, leaves, and other tender plant parts and suck out fluids." Basically, they're pear-shaped insects with long legs and long antennae and may be green, yellow, brown, red or black "depending on the species and the plants they feed on," according to UC IPM. "Almost every plant has one or more aphid species that occasionally feed on it. Many aphid species are difficult to distinguish from one another; however, management of most aphid species is similar."
"A few species appear waxy or woolly due to the secretion of a waxy white or gray substance over their body surface. Most species have a pair of tubelike structures called cornicles projecting backward out of the hind end of their body. The presence of cornicles distinguishes aphids from all other insects."
UC IPM also says that most aphids don't move rapidly when disturbed. That's the truth! Sometimes they're just a 16th of an inch away from a lady beetle that's gobbling up their siblings.
The lady beetles in our garden today were primarily the multicolored Asian lady beetles (Harmonia axyridis), also known as Harlequin lady beetles. They're native to China, Russia, Korea and Japan. In colder parts of the world, they're considered a nuisance when they overwinter in large congregations in walls, windows or attic. They leave unpleasant odors and stains.
Friend or foe? They're more of a friend, at least here in sunny California.
- Author: Kathy Keatley Garvey
The circle of life...
Monarch caterpillars feast on milkweed, their host plant. Oleander aphids feast on the juices of milkweed plants. Lady beetles, better known as ladybugs (but they're beetles, not bugs) feast on the aphids.
The milkweed is the only plant that the monarch caterpillars eat. Oleander aphids, as their name implies, are also commonly found on oleander. And lady beetles not only eat aphids, but soft-bodied insects such as scales, white files, mites, and yes, monarch butterfly eggs.
The UC Statewide Integrated Pest Management Program (UC IPM) says California has some 200 species of lady beetles and that "most are predators both as adults and larvae."
If you've ever watched a lady beetle go through the aphid cafeteria and select the menu (big, little, small, winged, wingless, fast, slow, near, far), it's quite a sight.
One lady beetle can eat 50 aphids a day, scientists say. During its lifetime, that can mean 5000 aphids.
As for the oleander aphids (Aphis nerii), they derive their name from Nerium, the genus name for oleander. Both are the oleander and oleander aphid are reportedly native to the Mediterranean region.
If you have milkweed, you probably have aphids. Oleander aphids. And you probably have lady beetles eating those aphids. And the monarch eggs...
The circle of life..
- Author: Kathy Keatley Garvey
Monarch butterflies aren't the only insects that like milkweed.
Honey bees, lady beetles and aphids, do, too.
We found all three insects, plus a monarch butterfly, on our scarlet milkweed (Asclepias curassavica) today (Labor Day). Most of the insects were oleander aphids, which attract lady beetles. aka ladybugs.
Asclepias curassavica, also known as tropical milkweed, and Mexican butterfly weed, is native to South America but is frequently planted throughout the United States to attract monarchs. In the United States, you'll find it not only in California and Florida, but in Hawaii, Louisiana, Tennessee and Texas, among others states. The colorful plant is known by some as "redhead," due to its brilliant red (and yellow) flowers.
Unfortunately, some of the "yellow" is a pest that needs to be eradicated. See the UC Statewide Integrated Pest Management Program (UC IPM) guideline on aphids.
- Author: Kathy Keatley Garvey
What's for lunch?
If you're a lady beetle (aka ladybug), a good bet is you'll have one of those yummy, plant-sucking aphids. In fact, you'll eat your fill. Please do.
Today we walked behind the Life Sciences Building on the UC Davis campus and encountered scores of our polka-dotted, six-legged, dome-shaped buddies hunting for prey.
It was easy pickings.
This was a fast predator in a slow food movement.
Aphids were everywhere on the brittlebush (Encelia farinosa).
Call lady beetles what you will. Ladybirds. Lady beetles. Ladybugs. Coccinelles. Beneficial insects. All of the above.
Most people in America, however, know this insect as a "ladybug." It's actually not a true bug but a beetle. It's a member of the Coccinellidae family. Coccinelid is Latin for "scarlet," but not all lady beetles are scarlet with black spots. Some are yellow, orange and brown, and some with spots and some without.
You'll find coccinellids worldwide as there are more than 5,000 species, and of that number, more than 450 are native to North America, according to Wikipedia.
And they all "do lunch" with aphids, scales and other soft-bodied insects.
- Author: Kathy Keatley Garvey
Decisions, decisions...
Where's the best spot for the new residents of my garden?
I acquired two ladybugs last Saturday during the 99th annual UC Davis Picnic Day. Background: as part of the campuswide celebration, the Department of Entomology annually hosts an all-out bugfest at the Bohart Museum of Entomology and at Briggs Hall. And keeping with the Briggs Hall tradition, the UC Statewide Integrated Pest Management Program gifted picnickers with the treasured ladybugs.
Now ladybugs aren't really "bugs"; they're beetles. Neither are they all "ladies"; some have manly qualities. (Gender issues may confuse us, but not the lady and gentlemen beetles.)
A ladybug is a good beneficial insect. It can devour an estimated 5000 aphids in its lifetime (three to six weeks).
So, every year for the past several years, I've adopted two ladybugs, chauffered them home, and tucked them in our garden. "Please eat the aphids," I tell them.
And they do.
They're good at following instructions.
Last year they took up residence in a bed of red roses. This year, they're coming up in the world--a high rise. A tower of jewels (Echium wildpretii) is "home sweet home."
Life doesn't get any better than this if you're a ladybug (and any worse if you're an aphid).