Thoughtful of the moms, isn't it? Moms are like that.
Look on or under your rosebush leaves. Look under your milkweed leaves. See the cluster of tiny yellow eggs? And if you look closely, you'll see those pesky aphids sucking the sap, the very lifeblood, out of the plant.
The lady beetle eggs hatch in about a week. The larvae look like little alligators (many a gardener has killed them, not knowing these are beneficial insects, not pests.) Larvae, too, devour aphids. As adults, lady beetles can polish off about 75 aphids a day.
Lady beetles hibernate during the winter, huddling under leaves, rocks or grasses. (See more about lady beetles on the UC Statewide Integrated Pest Management Program website.)
But for now, you'll see them laying eggs--right where the food source is.
Thoughtful of the moms, isn't it? Moms are like that.
Monarchs lay their eggs on the underside of milkweed leaves--generally--but we've seen them on stems and on the leaf edges. They usually deposit a single egg beneath the leaf, but we've spotted as many as four on one leaf. They secrete a glue so the egg will adhere.
Color? They're a creamy yellow with narrow longitudinal ridges from the top to the bottom. Size? About 0.9 to 1.2 mm long, or about the size of a pinhead.
They hatch about 3 to 4 days after they're laid. Then you'll see the black-headed tiny larva or caterpillar eating its shell before it begins devouring the leaf.
Some folks confuse the sap-sucking yellow oleander aphids with the monarch eggs. Or the yellow eggs of the lady beetle, aka ladybug. So we took a few images of them.
In our family pollinator garden in Vacaville, we've collected about 250 monarch eggs or caterpillars this year, and the mamas are still laying eggs! We're not the only ones who like monarchs. We try to collect the eggs before the predators and parasitoids get them. Predators include lady beetles (ladybugs), spiders, milkweed bugs, lacewings, and wasps. Tachinid flies and other parasitoids lay their eggs in or on the immature monarchs or deposit their eggs on a leaf that the caterpillar eats. The fly larvae develop inside the living host, killing it. Note: tachinid flies are considered beneficial insects when they lay their eggs in such pests as cabbageworms.
We grow five species of milkweed:
- Tropical: Asclepias curassavica
- Narrowleaf: Asclepias fascicularis
- Showy: Asclepias speciosa
- Butterfly weed: Asclepias tuberosa
- Swamp milkweed: Asclepias incarnata
But back to the question: how can you tell the difference between an oleander aphid and a monarch egg? They are so tiny and both are yellow! Basically, the aphid has legs and it moves! Some aphids are winged and fly. Another clue: aphids cluster together; you won't find monarch eggs in a cluster.
Note that the lady beetle lays her eggs in clusters, so if you find a cluster of eggs, those aren't monarch eggs.
The three "F's" win hands-down: family, friends and food.
But "insects" should definitely added to that list. They are among the tiniest of critters on this planet, but think of their importance in our lives and in our ecosystems.
As British entomologist-zoologist George McGavin, author, academician, explorer and television presenter wrote in an article published in 2004 in The Guardian: "They are the most successful multi-cellular life form on the planet...Insects have endured for hundreds of millions of years. They have survived the numerous global upheavals and catastrophes that spelled the end for much greater and grander creatures and they will continue to be a major part of the Earth's fauna for many more millennia."
McGavin, an honorary research associate at both the Oxford University Museum of Natural History and the Oxford Department of Zoology, points out that insects are "the food of the world."
"Most of the higher animal species on Earth eat insect--they are the food of the world," he writes in his piece on Why I Love Insects. "All of the blue tit chicks in the British Isles alone consume 35bn caterpillars before they become adult. A single pipistrelle bat, the smallest bat species in the UK, has to eat between 2,000 and 3,000 insects most nights to stay alive."
McGavin also emphasizes the importance of pollinators and recyclers, that "we depend on bees for perhaps as much as a third of the food we eat....As recyclers, flies and beetles devour carcasses and clear prodigious quantities of dung every day."
We met George McGavin in July 2012 at a sunflower field in Winters. He and his crew were there to film a documentary on ultimate swarms, featuring Norm Gary, emeritus professor of entomology at UC Davis. Gary, an author, scientist and now a retired professional bee wrangler, clued him in on bee behavior.
Like many scientists, McGavin loves to share his enthusiasm for insects, something we all need to appreciate more and to support as much as we can. For example, the Entomological Society of America launched a Chrysalis Fund to bring insect education into the classroom. According to the website, it's "supported by donors dedicated to the mission of enhancing insect education for K-12 students. Teachers and educators with creative ideas for insect-themed programs or projects are encouraged to apply for funding." (On a side note, UC Davis distinguished professor Walter Leal donated his $1000 honorarium from the recent ESA Founders' Memorial Award Lecture to the Chrysalis Fund. See YouTube video.)
So, what are we thankful for? Family, friends and food, for sure.
And the list also includes...insects.
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.