Phytotelmata: Miniature Breeding Grounds for Mosquitoes and Rat-tailed Maggots

July 26, 2016

The author, Emily Hartop, investigating a phytotelma formed by exposed tree roots. Photo by Brian Brown. One of the many benefits of doing research in urban environments is the ability to spend a day in "the field" by simply walking out your door. Brian Brown (Curator of Entomology at NHMLA) and I did just that on a recent morning, and found ourselves investigating some unexpected phytotelmata in the exposed roots of large Ficus trees growing in front of the Exposition Park Rose Garden next door to the NHMLA. Phytotelma (plural phytotelmata) is a fancy word that translates as "plant pond" and refers to any captured water environments created by plants. Some plants have evolved specifically for this purpose, like carnivorous pitcher plants . Other phytotelmata are quite accidental, such as holes in logs or trees, bamboo internodes, or leaves or flowers that capture water. These ponds are often host to many types of immature aquatic insects, and can be teeming with life. The small ponds we found in the Ficus roots were no exception.

Immature mosquitoes thrive in murky phytotelmata! Photo by Brian Brown. The first thing we noticed in these phytotelmata were hundreds and hundreds of mosquito larvae (photo above). Although the first pond we explored (pictured at top) was shallow and less than two feet long by eight inches wide, it easily contained several hundred mosquito larvae (detail photo of a larva below). This reinforced an important lesson about captured water: the smallest environment can breed incredible numbers of insects! This is why checking for standing water in potted plants, and overturning buckets so they don't collect water is so important. A container left carelessly in the backyard that collects a bit of sprinkler water can, within just a few days, turn into a house full of mosquitoes.

A mosquito larva displayed on a leaf. Photo by Brian Brown. Although there were a number of aquatic maggots that we observed, many of them we will need to collect and rear to adulthood to identify. We did find one real beauty that is instantly recognizable, however! Eristalinus taeniops, an introduced flower fly whose larvae are commonly called "rat-tailed maggots" (see photo below) were buzzing around a particularly stagnant (and stinky!) phytotelma we investigated. It wasn't long before I spotted one of the large, squishy maggots in the putrid water, and thrust my hand into the rotting water! For science! The maggot is pictured below (my hands still smell)! 

A rat-tailed maggot pulled from the stinky depths! Photo by Brian Brown. Rat-tailed maggots are able to live in the smelliest, most stagnant of waters because of their breathing tube "tail". Although their beginnings are stinky and they aren't the most attractive of maggots (although I think they're adorable), as adults they are known as Stripe-eyed flower flies and they are the most gorgeous, impressive honey bee mimics you might ever see (photo below). 

A stripe-eyed flower fly resting on a tree root near the phytotelma where we found rat-tailed maggots. Photo by Brian Brown. This species was previously found in the NHMLA Nature Gardens, but attempts to locate the larvae nearby had been unsucessful. Perhaps these beauties have been developing in the phytotelmata next door for years! It was an amazing morning that exposed a miniature world so close by, but unexplored. It was a great example of what makes urban environments so exciting: they are constantly changing and full of unexpected surprises!

 

(Posted by: Emily Hartop)


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War of the Larvae: Ladybug Grub Eats Flower Fly Maggot!

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.”  

(Posted by: Karen Klabin)

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Aphid Eating Flower Fly Found in North Campus

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.

Flower Flies of Los Angeles County

Thanks to Brian Brown and Jim Hogue for supplying fly information and identifying the fly specimen.

(Posted by: Lila Higgins)

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