Milkweed bugs gained the nickname of "seed eaters" for primarily eating the seeds of milkweed.
Actually, they are opportunistic and generalists, says Hugh Dingle, emeritus professor of entomology at the University of California, Davis.
They will eat monarch eggs and larvae (milkweed is the host plant of monarchs), as well as the oleander aphids that infest the milkweed.
We recently watched a large milkweed bug (Oncopeltus fasciatus) munch oleander aphids on a narrow-leafed milkweed (Asclepias fascicularis) in our pollinator garden in Vacaville, Calif. Between the milkweed bugs and the lady beetles, aka ladybugs), they absolutely cleaned off all the aphids, the first time in years.
Milkweed without aphids? Unbelievable! That's like macaroni without cheese, a pencil without paper, or a hammer without a nail. It's a "given" that if you grow milkweed, you'll get aphids. Some monarch butterfly enthusiasts kill the aphids with a soapy water mixture (which we've done in the past), but this year, we let biocontrol reign.
It worked wonderfully!
"Milkweed bugs will get protein from wherever they can find it," says Dingle, an insect migration biologist and author of the textbook, Animal Migration: the Biology of Life on the Move. They've been known to feed on insects trapped in the sticky pollen of the showy milkweed (Asclepias speciosa). And on nectar.
Dingle served as a professor at UC Davis Department of Entomology from 1982 to 2002, achieving emeritus status in 2003. National Geographic featured him in its cover story on “Great Migrations” in November 2010. LiveScience interviewed him for its November 2010 piece on“Why Do Animals Migrate?”
A fellow of the American Association for the Advancement of Science and the Animal Behavior Society, Dingle has done research throughout the world, including the UK, Kenya, Thailand, Panama, Germany and Australia.
Dingle is a former secretary of the International Society for Behavioral Ecology and past president of the Animal Behavior Society. He received the Edward A. Dickson Professional Award in 2014 to do research on "Monarchs in the Pacific: Is Contemporary Evolution Occurring on Island Islands? (See news story on Department of Entomology and Nematology website.)
Wait! They may NOT have been ladybugs, scientifically known as lady beetles, family Coccinellidae.
“I'm still not convinced that the swarms are ladybugs,” Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis, told us Friday. “It's pretty late in the season for them and apparently there's no hard evidence for ladybugs except anecdotes that folks have seen a lot of ladybugs in the region. We were seeing a lot of ladybugs in the Imperial Dunes when we were there in March.”
Scientists spotted the cloud, about 10 miles wide and a mile above the ground around 9 p.m. They ruled out bats and birds. The temperature in the air? About 40 degrees or lower—considered too cold for ladybugs.
“Forty degrees is too cold for their flight muscles, but if there's a wind and they've already warmed up, it's possible they could stay airborne,” Kimsey said, adding she'd like to see some hard evidence that these were indeed ladybugs. “Otherwise this is all just speculation.”
The ladybugs were thought to be the migratory convergent lady beetles, Hippodamia convergens. Some 200 species of ladybugs reside in California. (See information on this beetle on the UC Statewide Integrated Pest Management Program website.)
Speculation abounds. Why the huge swarm? Maybe it was the result of a combination of cues, such as temperatures and length of day, climate change (wildfires?), and lack of food? A perfect storm?
Kimsey told reporter Maanvi Singh of The Guardian in a June 7th news story: “It's too bad there wasn't anyone in a private plane up in the air at that time. We could've figured it out based on which dead insects were splatted across the wings.””
Kimsey knows about those bug splats. She was the nation's only entomologist selected for the NASA SPLAT/Boeing team to research how to decrease bug splats on aircraft and thus increase fuel efficiency in commercial jets. NASA engineers developed four different surface treatments designed to repel bugs and Boeing developed wing modifications to test an aircraft at Shreveport, La.
By the way, a Boeing EcoDemonstrator 575 took flight, reaching an altitude of 5000 feet to maximize bug splats. The panels generated 100 and 500 splats each. Kimsey identified all the insects and found that a relatively small number of species caused the bulk of the splats. They included flower flies, aphids, thrips, muscid flies, midges, mosquitoes and love bugs. Kimsey's excellence in teaching, research and public service led to her being named the 2016 recipient of the Academic Senate's Distinguished Scholarly Public Service Award and a comment from her nominators that her SPLAT research was a "great public service to NASA, the airline industry and worldwide passengers who depend on air travel."
Naturalist Greg Kareofelas, an associate at the Bohart Museum of Entomology, has never seen such a cloud but has photographed lady beetles overwintering in California's Coast Range. "When they are at the place they will spend the winter, they hide under leaves and other detritus and unless you dig down to the ground level, you don't really see them or notice they are there. I guess this is the way they are protected from the cold. I know the places I have found them are under snow for the winter. It is only when they are ready to disperse in the spring, do they congregate like on tree trunks and other places above ground level."
UC Davis emeritus professor Hugh Dingle, author of Migration: The Biology of Life on the Move (second edition, 2014, Oxford University Press), a sequel to the first edition published in 1996, says the cloud may have been lady beetles. "I guess lady beetles, but I suspect other insects were in the swarm as well."
"This one was especially large, but yes, there have been other swarms showing up on radars, especially locusts, some moths," Dingle said. "Could also have been moths, grasshoppers, etc. I confess, though, that the swarm was so large that I wonder if there was a glitch somewhere on the radar or something?"
Now if there had just been a plane near that cloud, as Kimsey pointed out, we'd have known exactly what was in that swarm.
Birds, bats, bloom? Unidentified objects?
Splat! Identified objects.
Have you ever seen the larva of a lady beetle (aka ladybug) dining on an aphid?
Lights! Camera! Action!
So here is this charming little immature lady beetle chowing down on an oleander aphid that has the audacity to infest the milkweed in our pollinator garden. Chomp! Crunch! Slurp! And then another aphid arrives on the scene. It does not flee. Aphids are not the smartest of insects.
Can you just wait! Hold on! I'm not finished eating this one, yet!
And then an adult lady beetle arrives. She ignores a fat aphid right before her very eyes. Shall we prey?
Can you just wait! Don't go away! I'll eat you when I'm hungry!
A lady beetle (it's not a bug, it's a beetle!) belongs to the family Coccinellidae. Scientists have described about 5000 species worldwide, and about 450 in North America.
How many aphids can a lady beetle eat in her lifetime of three to six weeks? An estimated 5000 aphids, according to the University of Kentucky Cooperative Extension Service.
That's great pest control!
One thing is for sure: the lady beetles and their offspring patrolling our milkweed plants will never experience famine. This is an all-you-can-eat buffet, and the aphids just keep on a'coming. They do not flee. Aphids are not the smartest of insects.
Now, where are the monarchs? We have milkweed waiting./span>
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>
How would you describe the year 2017?
Survival of the fittest?
In the insect world, it's more like "survival of the flittest."
If you've ever pulled up a chair in a pollinator garden and sat back and observed all the activity, sometimes it's like road rage on the freeway and aisle anger in the supermarket.
- Have you ever seen a male long-horned bee (Melissodes agilis) doing a protective fly-by, trying to save a food source for the female of his species?
- Have you ever seen a male long-horned bee challenging a Western tiger swallowtail seeking nectar from a Mexican sunflowers (Tithonia)?
- Have you ever seen a syrphid fly targeting a honeydew-laden lady beetle, aka ladybug, on a rose?
- Have you ever seen a honey bee and bumble bee racing for the nectar on catmint (Nepeta)?
You may if you plant a pollinator garden. Plant it and they--bees and butterflies and other pollinators--will come.
In Chinese astrology, 2017 was The Year of the Rooster. Coming Jan. 1: The Year of the Dog. But there's no "Year of the Insect."
If entomologists had their way, one of the 12 animals of the Chinese zodiac (rat, ox, tiger, rabbit, dragon, snake, horse, goat, monkey, rooster, dog and pig), would be switched to an insect. Insects matter. Indeed, scientists trace the first known fossil record of insects back some 400 million years ago. The insect? A springtail.
Insects easily outnumber us and all other life forms. The population of the world today is 7 billion, according to a World Population Clock. Insects? "At any given time, it is estimated that there are some 10 quintillion (10,000,000,000,000,000,000) individual insects alive," says the Smithsonian Institute. This amounts to to largest biomass of the terrestrial animals.
Other fascinating points to ponder from the Smithsonian Institute involve undescribed and described species:
"Most authorities agree that there are more insect species that have not been described (named by science) than there are insect species that have been previously named. Conservative estimates suggest that this figure is 2 million, but estimates extend to 30 million. In the last decade, much attention has been given to the entomofauna that exists in the canopies of tropical forests of the world. From studies conducted by Terry Erwin of the Smithsonian Institution's Department of Entomology in Latin American forest canopies, the number of living species of insects has been estimated to be 30 million."
"In the United States, the number of described species is approximately 91,000. The undescribed species of insects in the United States, however, is estimated at some 73,000." Four insect orders comprise the largest numbers of described species in the U.S.:
- Coleoptera (beetles): 23,700
- Diptera (flies): 19,600
- Hymenoptera (ants, bees, wasps): 17,500
- Lepidoptera (moths and butterflies): 11,500.
Today (the last Friday before the New Year) is a good time to think about "survival of the fittest" and "survival of the flittest" as we glance back at 2017 and look forward to 2018.
Happy New Year! And may all your gardens be pollinator gardens filled with bees and butterflies. And, a few syrphid flies, lady beetles...and...