It's a dog-eat-dog world out there.
It's also a 'cat-eat-'cat world, that is, when a caterpillar eats another caterpillar. Or in this case, when larva eats larva.
We recently spotted this lady beetle larva eating a syrphid fly larva on our yellow rose bush, "Sparkle and Shine." Both eat aphids, and that's exactly what they were doing until the lady beetle larva attacked--and began eating--the syrphid larva.
These insects are beneficial. The lady beetle, as an adult, continues to consume those pesky aphids. The syrphid fly adult, aka hover fly or flower fly, is a pollinator.
The hungry larva reminded us of Eric Carle's award-winning children's picture book, The Very Hungry Caterpillar, first published in 1969.
The synopsis (Wikipedia):
"One Sunday morning, a red-faced caterpillar hatches from an egg, and begins to look for some food. He eats through increasing quantities of fruit on the following five days, one apple on Monday, two pears on Tuesday, three plums on Wednesday, four strawberries on Thursday, and five oranges on Friday, and then, on Saturday, he has an enormous feast. By the end of Saturday, the inevitable happens and he is ill. After recovering from a stomach-ache, he returns to a more sensible diet by eating through a large green leaf before spinning a cocoon in which he remains for the following 2 weeks. Later, the 'big fat caterpillar' emerges as a beautiful butterfly with large, gorgeous, multi-coloured wings."
Well, in this case, the menu differed. Our lady beetle larva didn't eat an apple, pear, plum, strawberry or orange.
He/she ate its competitor.
So here's this lady beetle patrolling a rosebud. It's early spring--April 15--in Vacaville, Calif.--and our little subject is looking for some tasty aphids. Or perhaps a mate.
Oh, a visitor is on my rosebud, heading right toward me. Identify yourself, please!
It's a wasp, a male parasitic wasp from the family Ichneumonidae (as identified by Robbin Thorp, distinguished emeritus professor of entomology at UC Davis).
The Ichneumon wasp is probably looking for a girlfriend. The lady beetle does not meet its expectations.
The wasp hurriedly flies off. Its mate, when it finds one, will lay her eggs in caterpillars, including such pests as armyworms, cabbage loopers, tomato fruitworm and tussock moths, much to the delight and appreciation of agriculturists. The eggs hatch into larvae, which develop inside the host, killing it. Adult wasps emerge and the cycle continues.
The wasp family is aptly named. "Ichneumon" comes from the Greek word meaning "tracker," a reference to its search for a host. Where's a caterpillar when you need one?
Charles Darwin seemed a bit troubled by this, describing these parasitic wasps as "feeding within the living bodies of caterpillars." The caterpillar shrivels up and dies.
Ichneumonidae is a big, big family of feeders. The number of described species? More than 24,000 worldwide. However, "estimates of the total species range from 60,000 to over 100,000--more than any other family in the order Hymenoptera," according to Wikipedia. That's probably more than any other family in the insect world, or for any other family, for that matter.
Says BugGuide.net: "They vary greatly in size and color; many are uniformly colored, from yellowish to black and others are brightly patterned with black and brown or black and yellow; many have middle segments of antennae yellowish or whitish. The majority resemble slender wasps but differ from the stinging wasps (Scolioidea, Vespoidea and Sphecoidea) in having longer antennae with more segments (usually at least 16). Many have long ovipositors, often longer than the body."
"Ichneumonids are notoriously hard to identify: aside from the sheer number of species, there are numerous cases of distant relatives that appear almost identical," BugGuide points out. "Any identification based solely on comparing images should be treated as suspect unless an expert has said there are no lookalikes for the species or group in question."
Can the larvae of lady beetles (aka ladybugs) eat aphids?
Yes, they can. And yes, they do.
We spotted some lady beetle larvae on our yellow roses today and guess what they were doing? Right, eating aphids. Eating lots of aphids.
The larvae look a little like miniature alligators, which is probably why they're often mistaken for pests.
Oooh, what's that weird-looking thing on the roses? It can't be good. Kill it!
Sadly, that's what many people do.
Lady beetles (family Coccinellidae) are beneficial insects that gobble up aphids, mites, scales and other soft-bodied insects. Check out the Quick Tips on the UC Statewide Integrated Pest Management Program (UC IPM) website for more information and photos.
And, be sure to attend the 103rd annual UC Davis Picnic Day on Saturday, April 22. It's "open house" throughout the campus. At Briggs Hall, the UC Davis Department of Entomology and Nematology and UC IPM will answer your questions about insects (as will scientists at the Bohart Museum of Entomology in Room 1124 of the Academic Surge Building). (See news story.)
Bugs. Briggs. Bohart. What could be better? Well, youngsters visiting the UC IPM booth at Briggs Hall are in for a special treat: they will be gifted with lady beetles to take home. Watch out, aphids!
Oleander aphids, those cartoonish-looking yellow insects with black legs and cornicles, are commonly found on oleanders. Hence their name. But they also are partial to milkweeds, the host plant of the monarch butterfly.
It's a daily challenge to rid those Draculalike pests from our milkweed plants. They pierce the tender stems and suck out the plant juices. Hey, do you mind? Those milkweeds are reserved for monarchs!
Fortunately, lady beetles, aka lady bugs, come to the rescue! Unfortunately, lady beetles also dine on monarch eggs.
It's a case of predator vs. prey (lady beetles vs. aphids) and beneficial insect vs. beneficial insect (lady beetles vs. monarch eggs).
Today something a little more unusual happened.
An oleander aphid hitched a ride on the back of a lady beetle. Apparently unaware of the hitchhiker (fast food at that!), the lady beetle kept gobbling up the aphid's relatives in an all-you-can-eat buffet.
We watched the lady beetle scurry up and down the mllkweed and then take off with the aphid securely on its back.
The lady beetle became the pilot, and the aphid, the passenger. The fair game became a free fare.
How do you control aphids on milkweed but still keep the monarch eggs?
An article appearing Nov. 9, 2012 in the Los Angeles Times had this to say:
"Monarch eggs are more tightly attached to leaves than aphids, so with just the right amount of pressure you may be able to wash off aphids without destroying the eggs.Sprayed water may only dislodge the pests, which can climb back up on their own or be returned by aphid-harvesting ants. Soapy water may dislodge and kill more aphids, but it also is more damaging to the monarchs and can build up on the plant."
"Though tedious, dabbing aphids with cotton swabs dipped in isopropyl (rubbing) alcohol is most effective. That kills them outright. Alcohol, however, also is lethal to monarch eggs and larvae, so care must be taken when dabbing."
For more about aphids, be sure to read the UC Statewide Integrated Pest Management's Pest Note. Be aware that aphids are not just sucking pests. They can also transmit viruses. "Squash, cucumber, pumpkin, melon, bean, potato, lettuce, beet, chard, and bok choy are crops that often have aphid-transmitted viruses associated with them. The viruses mottle, yellow, or curl leaves and stunt plant growth."
Down on the farm...the Loma Vista Farm....
When the Loma Vista Farm--part of the Vallejo City Unified School District--recently hosted its annual Spring Festival, scores of folks came to see the animals, buy a plant or two, and participate in the many activities.
But if you looked closely, you could see that the farm, located at 150 Rainier,Vallejo, is also a pollinator habitat and home to many insects.
Lady beetles, aka lady bugs, munched on aphids in the garden (the garden feeds Vallejo school children as well). Those pesky spotted cucumber beetles also showed up. We spotted a beneficial insect (lady beetle) and a pest (spotted cucumber beetle) sharing a leaf.
A Western tiger swallowtail fluttered down to the aptly named butterfly bush for a sip of nectar. The caterpillar of an anise swallowtail dined on the leaves of its host plant, anise, also called fennel. (It smells like licorice to us!)
All the while, a colony of yellow-faced bumble bees, Bombus vosnesenskii, went about their bees-ness, entering and exiting a hole in the ground in a pattern that would alarm human air controllers. They zigged, zagged and then bumbled through with huge pollen loads, sometimes nearly colliding.
The Loma Vista Farm is also the habitat of "Farm Keeper" Rita LeRoy, who has worked for the Vallejo school district for 25 years. She teaches students about nature and nutrition through hands-on farm lessons involving cooking, gardening, insect appreciation, and animal care. She is an avid entomological enthusiast, an insect photographer, and a member of the Pollinator Posse.
Founded in 1974, the Loma Vista Farm is described on its website as a 5-acre outdoor classroom that provides hands-on educational activities involving plants and animals for children of all ages and abilities. "We seek to increase students' knowledge of nature and nutrition while enhancing academic learning, ecoliteracy, and psychosocial development."
The farm offers field trips, after-school opportunities through 4-H, community service and volunteer opportunities, garden-based workshops for adults, and job training for college students, developmentally disabled young adults, and disadvantaged youth.
It's open to the public Monday through Friday from 9 a.m. to 2:30 p.m. during the school year.
It's open to insects year around!