January 10, 2017
The Museum's Nature Gardens continue to be the gift that keeps on giving by providing precious habitat to wildlife living in the urban core of LA. Last November, we not only had our second alligator lizard sighting, but we also uncovered a rarely seen flower fly from our Malaise trap that collects insects as part of the BioSCAN project. This project has examined over 2,000 flower fly specimens representing 35 species in LA so far, but this rare fly from the garden, Myolepta cornelia, is the only one we have seen so far!
Before you dismiss this finding as “just another fly,” take a minute to ponder the many talents of these mini-marvels. Faster than a hummingbird, clocking in at 250 wing beats per second (!!!), flower flies spend their day revelling in the garden’s floral buffet. They can fly backwards as easily as they do forwards, or can be spotted hovering perfectly still in mid air, like little meditating, levitating yogis. Just like the beloved bee, they pollinate the flowers they feed upon. In fact, as hymenopteran (the bee, wasp, and ant group) mimics many are mistaken for a wasp or a bee, a trait that offers protection from potential predators.
Their ecological importance does not end there. As wee little fly babies (the maggot or larval stage, in other words), they act as beneficial predators or decomposers, depending on the species. The activity of the larva of our rare special fly M. cornelia is still a mystery to entomologists! We know that many of their close relatives feed on rotting wood in the larval stage and have a preference for oak woodlands, so it is possible that M. cornelia is helping to break down dead wood in the Nature Gardens.
Special thanks to Jim Hogue and Martin Hauser for their identification skills and syrphid fly insight!
Brown, Brian, James N Hogue and F. Christian Thompson. "Flower Flies of Los Angeles County". Natural History Museum of Los Angeles County. 2011.
Reemer, Menno, Martin Hauser and Martin C. D. Speight. "The genus Myolepta Newman in the West-Palaearctic region (Diptera, Syrphidae)." Studia dipterologica 11 (2004) Heft 2: 553-580.
May 24, 2016
Immature ladybug eating flower fly larva, photo by Brian Brown.
Urban Nature Research Center (UNRC) co-director Dr. Brian Brown recently wandered out of his home into his Monrovia backyard and caught sight of something unexpected on the outside of his insect trap: an immature ladybug (also known as a larva or grub) consuming the larva of a flower fly (also known as a maggot). The large, tent-like Malaise trap—used in the UNRC's BioSCAN project to collect and study flying insects from multiple sites across Los Angeles—has a sloped, white mesh cover that serves as a perfect backdrop to capture an image of a bristly black and orange ladybug larva mid-meal.
Brian’s Malaise trap sits at the foot of an old, towering Valencia orange tree, which thrives and produces massive amounts of citrus despite hosting armies of what most of us consider garden pest enemies.
“The tree is festooned with scale insects, aphids and whitefly,” Brian says.
The tree is never sprayed with any kind of pesticide or treatment, and for that reason beneficial insects, with their smorgasbord of dinner options, are a year-round presence in Brian's garden. The larvae of both ladybugs and flower flies are voracious predators, eating hundreds of soft-bodied, sap-sucking pests and are prized inhabitants of his garden.
“Ladybugs are thought of as cute, storybook creatures. They're actually lions, ferocious predators as larvae and adults.”
What struck him about the vision of a ladybug larva chowing down on a fellow beneficial bug? It's not often, he says, you see one beneficial insect consuming another. “It challenges how we think about what it means to be beneficial.”
November 16, 2012
Earlier this week I was outside being interviewed about Entomophagy, the practice of eating bugs. While they were setting up the camera and sound equipment I took a few moments to see what insects were visiting the bright yellow flowers on the bush I was standing next to. Among the usual honeybees, I saw a massive black fly. This fly was huge (3/4 of an inch in length) and really stood out against the yellow flowers.
It was a Mexican cactus fly, Copestylum mexicanum, feeding on nectar, and this was the first time I had seen them around the Museum!Here's what Flower Flies of Los Angeles County book has to say about them:"This is the largest flower fly in Southern California, with a body length of 18mm. It gets its name from the larvae that feed in wet decaying prickly pear cactus. Adults are commonly seen feeding on flowers. Although it resembles some carpenter bees this species looks more like a large horse fly. The Mexican cactus fly is found from the southern USA to Central America, but related cactus-feeding flower flies are found in Mexico and South America. Many other species of the large genus Copestylum are found in our area. None of them resemble the cactus fly; instead they mimic bees and other stinging insects. All feed on decaying organic matter."*Thanks to Museum Curator of Entomology, Brian Brown, for identifying the fly!
January 20, 2012
There are over 150,000 species of flies in the world! Most visitors who come to the Museum can name only a few of these flies (house fly, horse fly, or mosquito for examples) and many hold the belief that we would be better off without flies in our world. On Wednesday, January 18, we found a fly that I am sure will help you realize that all flies can't be cast as "bad" characters — I introduce the humble aphid eating flower fly, Eupeodes volucris.
Female Eupeodes volucrisPhoto taken by Jerry FriedmanWhy do people like these flies and not others? This isn't an easy question to answer, but I'll have a go... First of all, these flies eat aphids and as any gardener will tell you, aphids are a serious garden pest. Secondly, they belong to a family of flies known as “flower flies” so called for their proclivity to visit flowers and suck down nectar. Thereby they play a role in pollination. Finally, if you look closely at these small flies you'll see why a lot of geeky people, like myself, think they are quite beautiful. Not only are they brightly colored and highly patterned, when their eyes catch the sunlight just right they have an iridescent sheen! Although I might add that E. volucris isn't as flashy as its close relative, the aptly named stripe-eyed flower fly, Eristalinus taeniops, also a native to the Los Angeles area.
Stripe-eyed flower flyPhoto courtesy of What's That Bug websiteHow does a fly eat an aphid? It is actually the larval stage of the fly, or maggot that chows down on aphids. Much like immature ladybugs they trawl through a sea of aphids on a plant and chomp any that get in their way! Though they don't have quite the same look as a ladybug!
Flower fly maggots eating oleander aphidsPhoto courtesy of What's That Bug websiteTo find out more our local flower flies, swing by the Museum gift shop to get a copy of our latest entomological publication, Flower Flies of Los Angeles County.
Thanks to Brian Brown and Jim Hogue for supplying fly information and identifying the fly specimen.
August 12, 2016