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.
It is not a "pretty sight," as Ernest Hemingway might have said, to see a honey bee stuck like glue--nature's "gorilla glue?"-in the reproductive chamber of a milkweed.
It's a trap, a floral trap.
If you've never seen this, this is how it works: milkweed produces pollinia, a sticky structure or packet of pollen grains originating from a single anther (male part). During the flower's complex pollination process, the mass is transferred as a single unit and looks like a yellow wishbone dangling on a honey bee's legs or other parts of her anatomy. It's a devious way for the milkweed to force insects to help them reproduce--in exchange for the sweet nectar reward. (Orchids produce pollinia, too.)
Oh, the nectar is so enticing! Honey bees (and other insects) literally make a bee-line for the it. They buzz and bump around as they await a vacancy. The scenario almost calls for crowd control or at least traffic lights.
But it's a trap, a floral trap. Sometimes you'll see frenzied bees struggling to free themselves from the sticky nectar trough. They are not always successful. Return to the scene of the grime and you'll see insect parts or whole insects trapped in the sticky mass. Dead.
The two honey bees below experienced different fates on this narrow-leafed milkweed, Asclepias fascicularis. One managed to free her leg from the grip of the milkweed reproductive chamber and return to her colony, complete with the precious nectar--and legs intact. The other did not. The meal was her last.
Ever seen a back-lit monarch butterfly?
It's like a stained-glass window in a centuries-old steepled church where you cannot see the ugliness of the world, but its beauty.
Monarchs are like that. Those iconic butterflies excite, inspire and transform you, just like stained glass windows.
We captured these images at dusk of a monarch fluttering around an aphid-infested milkweed, a tropical milkweed, Asclepias curassavica, on Aug. 7 in Vacaville, Calif.
The orange butterfly was nothing but a blur until we stopped the action (1/4000 of a second) with a 200mm macro lens mounted on a Nikon D500.
The beauty (the monarch) eclipsed the beast (oleander aphids) in a moment of time.
Which one is the most popular? Initially, it was the tropical milkweed, A. curassavica. We collected the first five caterpillars there. The A. fascicularis yielded the rest.
So, the count: narrowleaf milkweed, 11; tropical, 5; and showy, a no-show.
To date this year, we have released six monarchs back into the garden. The others went for university research. Elizabeth Pringle's laboratory at the University of Nevada, Reno, needed male and female monarchs to rear a colony, and the UC Davis laboratory of Louie Yang needed some tachinid flies.
Unfortunately for us--and fortunately for the Yang lab--tachinid flies infested two of our "11-piece collection." The adult flies are parasitoids that lay their eggs in immature monarchs (among other hosts). The fly larvae hatch and eat their host from the inside out. In a chrysalid, you can tell a tachnid fly infestation by the large tell-tale "dented" brown spot, it looks somewhat like a rotten spot on an apple. In a caterpillar? Think withered and discolored. Then a bungee-like white string appears, and the larvae (maggots) slide down--probably gleefully--like a kid on a Goliath Slide at the county fair.
Tachinids, however, are considered beneficial insects. They lay their eggs in or on such pests as cabbage loopers, cutworms, cabbage worms, gypsy moths, hornworms, harlequin bugs, lygus bugs, cucumber beetles, earwigs and the like. (See Bug Squad blog for close-up images of the tachinid larvae and pupae.)
2016: A Very Good Monarch Year
The year 2016 was a very good year for monarchs in our pollinator garden; we reared and released 60-plus. Sadly, the numbers fell drastically in 2017, 2018 and 2019. Last year, no eggs, no caterpillars and no chrysalids, and only a few monarchs passed through. In fact, in 2019 we did not see our first monarch until Aug. 9.
This year we're noticing a comeback of sorts. We spotted the first monarch on May 24. We now see:
- Males patrolling our yard and chasing the females--morning, noon and evening
- Females laying their eggs on the narrowleaf milkweed that's beneath the honeysuckle vine or the tropical milkweed that's beneath the roses
- Both males and females nectaring on milkweed, butterfly bush (Buddleia davidii), and Mexican sunflower (Tithonia rotundifolia), napping in the branches of the cherry laurels, and greeting any guests with flutter fanfare.
Life is good.
Sometimes the Gulf Fritillaries, Agraulis vanillae, that are hanging out on their host plant, the passionflower vine, mistake them for one of their own species and a pursuit begins.
Yes, the predators are out there: the California scrub jays, praying mantids, spiders, European paper wasps and yellow jackets. So are the tachinid flies and parasitoid wasps.
Would it be too much to ask them to...um....leave our monarchs alone? Yes.
Everybody eats in the garden. The menu choice is theirs.