Especially those oleander aphids that suck the very lifeblood out of our milkweed plants that we're struggling to save for monarch butterflies.
Just call aphids "The Enemy of the Gardener" or "The Enemy of the Milkweed."
The University of California Statewide Integrated Pest Management Program (UC IPM) describes 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. Almost every plant has one or more aphid species that occasionally feed on it."
"Aphids have soft pear-shaped bodies with long legs and antennae and may be green, yellow, brown, red, or black depending on the species and the plants they feed on," UC IPM tells us. "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.
"Generally adult aphids are wingless, but most species also occur in winged forms, especially when populations are high or during spring and fall. The ability to produce winged individuals provides the pest with a way to disperse to other plants when the quality of the food source deteriorates."
Not only do aphids stunt plant growth but they can spread viruses. Plus, they produce that sticky honey dew they that attracts ants and other insects.
Density? We've seen aphids so dense on our milkweed stems that all we see is yellow. (Sometimes we see red!)
We recently saw them magnified on a Leica DVM6 microscope, operated by Lynn Epstein, UC Davis emeritus professor of plant pathology, at a demonstration in Hutchison Hall. (See image below)
In California, most aphids reproduce asexually throughout most of the year, according to UC IPM. Did you know that a single aphid can generate as many as 12 offspring a day--without mating?
Bring on the lady beetles (aka lady bugs), lacewings, and soldier beetles! The larvae of lady beetles and syrphid flies also do their part in gobbling up aphids.
What to do when biological control doesn't work that well? Or when your lady beetles depart? Pinch the aphids; spray them with with water; or spray them with a mixture of 1 tablespoon of dish soap (Castile liquid soap) and one quart of water. Some folks dab aphids with cotton swabs dipped in isopropyl (rubbing) alcohol but that will kill the monarch eggs and larvae as well. We've found that spraying a mixture of sudsy soap and water works best for us.
Lather is the best medicine.
Just call them the "incredible aphid-eating machines."
That would be the lady beetles, commonly known as ladybugs (although they are not bugs; they're beetles belonging to the family Coccinellidae, and they're not all "ladies"--some are male!).
How many aphids can a lady beetle eat? Scientists figure around 50 a day. A single lady beetle can eat 5000 aphids during its lifetime, according to the University of Kentucky Extension Service.
That's why they're called beneficial insects!
And it's not just the adult lady beetles that dine on those plant-sucking aphids. So do the larvae.
The UC Statewide Integrated Pest Management Program describes lady beetles as "round- or half-dome-shaped insects with hard wing covers. About 200 species occur in California and most are predators both as adults and larvae. Some species specialize on aphids or other groups; others have a broader diet." (See Lady Beetles Card.)
What's for dinner?
Aphids. Maybe a 50-course meal?/span>
See those red spots on your milkweed seed pods?
Lady beetles (aka ladybugs or "garden heroes") are feasting on aphids.
And they're having a ball.
We've been watching the critters on our milkweed, Gomphocarpus physocarpus, for the last couple of months. The plant is a favorite among monarch butterflies, florists and interior decorators. This is the host plant of the monarchs; caterpillars eat only milkweed. It's also a "hostess" plant; florists add them to their floral bouquets and interior decorators grace their holiday tables with them. In fact, interior decorator Allison Domonoske of South Carolina transformed the White House Thanksgiving tablescape with moss, driftwood, pine cones, little white pumpkins and what she called "balloon-plant milkweed: large, green, ball-like flowers."
That was them!
We call them "lime green ball-like pods, covered with tiny spiny hairs"--or you could call them "spiky seed pods," as the Washington Post did. At any rate, they're often used for decorating.
Hmm, a forest green Douglas Fir Christmas tree adorned with lime green spiky seed pods? With red bows amid the green boughs? Gomphocarpus physocarpus to the rescue!
According to the Master Gardener Program, "the name physocarpa comes from the Greek physa meaning bladder and karpos, fruit, referring to the inflated, bladder-like fruits. It has a plethora of common names including balloon plant, balloon cotton-bush, balloon milkweed, bishop's balls, elephant balls, hairy balls, monkey balls, swan plant, and many others." It's also known as goose plant, giant swan milkweed, family jewels, Oscar, and by its former botanical name, Asclepias physocarpa.
It's a tall, spectacular plant that can reach a height of an NBA All-Star. Last summer monarch butterflies laid their eggs on it, lady beetles kept the aphids off it, and praying mantids kept everything off, including bees, butterflies and beetles.
If you have some growing in your garden, think holiday decorations...minus the red lady beetles, the First Ladies of the Garden, and their prey.
Fly away home.
Your house is on fire
And your children are gone.
How many times have you heard that nursery rhyme?
Better yet, how many times have you seen a lady beetle (because they're beetles, not bugs) take off?
Look closely for lady beetles in aphid-infested milkweed plants and you might see this phenomenon. The lady beetle opens its elytra (a modified hardened protective wing case) and out pop the wings.
This lady beetle (below) was munching and crunching aphids on a tropical milkweed this afternoon in Vacaville, Calif., and then opted to take flight. Just another beneficial insect eating soft-bodied pests and then heading off to another "restaurant" that features its prey.
Goes to prove that lady beetles are garden heroes. And when they take flight, they look like super heroes: the superman/superwoman of the garden.
You can learn more about lady beetles from the Natural Enemies Gallery, part of the UC Statewide Integrated Pest Management (UC IPM) website. "Although they are extremely important natural enemies of aphids, their propensity to disperse makes it difficult for them to be used in inoculative or inundative biological control programs," UC IPM points out.
Tell that to the children chanting the nursery rhyme and they'll probably grow up wanting to learn more about these amazing insects and it's not about their house being on fire: "Their propensity to disperse makes it difficult for them to be used in inoculative or inundative biological control programs."
So, here I am, an Asian lady beetle (Harmonia axyridis) perched on a rose bush in Vacaville, Calif., as dawn breaks. I'm eating aphids and minding my own beetle business, which consists of gobbling aphids and more aphids. And more aphids. Did I say more aphids? More aphids.
Wait, what's that? Something is heading straight toward me, its wings are flapping like crazy. Hey, I was here first. Go away!
Whoa, what are you doing? You've landed and you're licking me. What do you think I am, a honey stick?
That's what happened during a backyard encounter with an Asian lady beetle and a large syrphid fly. The fly, identified by senior insect biosystematist Martin Hauser of the Plant Pest Diagnostic Branch, California Department of Food and Agriculture, is a female Scaeva pyrastri.
Hauser and Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis, agreed that the syrphid fly is "going after honeydew on the beetle's head." Honeydew is a sugary, sticky liquid that aphids secrete when they're feeding on plant juices.
"The beetle was full of honeydew from feasting on aphids," Hauser noted, "and that is what the fly was after."