#Parasiteweek: Bird Blood-suckers

August 10, 2016

Ventral (underside) view
Dorsal (top) view


We have written before about bird louse flies (hippoboscids), but I never get tired of their flat, creepy look. Recently, our ornithology collections manager, Kimball Garrett, contacted me and said "Hey, Brian, are you interested in some hippoboscids from a least bittern (Ixobrychus exilis) from Malibu",- of course I was, what an unusual host from which to get hippos (what us entomologists endearingly call them)!

Let me note here that although they are called "bird louse flies, they are actually more like fleas, with the ability to easily move from one host to another (unlike their wingless, more sedentary namesakes). They feed on the blood of their bird "hosts".

Anyway, keying them out with my trusty "Manual of Nearctic Diptera", I came easily to the name Ornithoica, of which there were supposed to be two North American species. Intrigued enough to continue further, I looked up the latest key to species (which was from 1966!) and confirmed that the 5 flies all belonged to the species Ornithoica confluenta, known only from South America, the Caribbean, and southern Florida. At least, that was their known distribution in 1966; things might have changed, but it is undoubtedly a rare record!

(Photos by Kelsey Bailey)

(Posted by: Brian V. Brown)

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Beneath the Perch

June 23, 2017

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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Medfly Mayhem: The fly that shook L.A.

November 23, 2015

Photo by Kelsey Bailey. Insects inspire wonder, curiosity, fear or disgust, but very few have caused the widespread panic, political controversy, and public outcry like the Mediterranean fruit fly.  Shortly after appearing in California in the early 1980s, the saga of the Medfly erupted into a battle between the Agricultural Industry and the residents of the affected counties, with local politicians wedged firmly in between. As an entomologist from L.A., the aerial spraying of pesticide over the city to combat the Medfly that happened so long ago is still one of the topics I am most often asked about. It is firmly etched in many Angelenos’ memories, but most are unaware of what became of this notorious little fly.  

The Mediterranean fruit fly, Ceratitis capitata. Photo credit: Kelsey Bailey     First let’s take a moment to gaze upon the beauty of this insect: the yellow tiger-stripes, black bands, iridescent eyes, and sweet little face belies the damage this insect can cause. Medflies lay their eggs inside of a wide variety of fruit (apples, avocados, citrus-- to name just a few), and it is estimated that the total value of crops that could harbor destructive Medfly larvae (the “maggot” stage of the fly) is more than 7.2 billion dollars. This considerable financial threat to California’s agricultural industry set in motion a massive attack to try to eradicate the invasive pest 30 years ago. Helicopters loaded with the pesticide Malathion flew over L.A. and Orange counties, triggering hysteria as people were asked to stay indoors and cover their cars to reduce paint damage. Despite the best efforts by the authorities to state the low risk of this pesticide, the public was not persuaded. There was a collective negative gut reaction as some described the scene as reminiscent of “Apocalypse Now.” (In true L.A. fashion, the aerial spraying over L.A. inspired the opening scene of Robert Altman’s 1993 film “Short Cuts”).   The story gets stranger. As public outcry intensified and the federal government intervened against Governor Jerry Brown’s decision to halt aerial spraying, a bioterrorist group that called themselves “the Breeders” claimed responsibility for releasing more Medflies into targeted areas. In a letter sent to major newspapers and Mayor Tom Bradley’s office, the group threatened to continue releasing flies unless the aerial spraying ended.  To this day, no evidence has surfaced to confirm whether the releasing of Medflies by the Breeders was a hoax, but in light of the public relations fiasco and extreme opposition, it was clear another approach to a very serious problem had to be found. And it was.  

Sterile male Medflies are identified with a red dye marker. Photo credit: Kelsey Bailey.      If you look again at the fly portraits above, it’s possible they may seem familiar. Chances are that many of you reading this have seen a Medfly in L.A. before. On the surface, that may sound troubling, but the Medflies most often encountered are little heroes that are unknowingly fighting the good fight against, well, themselves. An ingenious method called the Sterile Insect Technique, implemented in the mid 1990s, is used to irradiate male Medflies, damaging their testes and making them infertile. The sterile male medflies are then airdropped out of helicopters like miniature secret agents, hopefully hitting their targeted areas but sometimes turning up in very surprising places. One sterile male Medfly was collected from the top of the U.S. Bank tower at a height of 1, 018 feet! Fortunately, all of that action does not stop them from seeking out love amongst the fruit trees, and the females are happy to oblige with these available sterile bachelors. The result is an astounding success story that has reduced the medfly infestations in L.A. by 93%, protected our state’s agricultural assets, and minimized pesticide use over urban areas.            

(Posted by: Lisa Gonzalez)


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Ant-decapitating Fly Found in Glendale!

November 18, 2013

I just found out we have ant-decapitating flies here in Los Angeles! Dr. Brian Brown, the Museum's Curator of Entomology and one of the world's foremost experts on flies, made a chance discovery by looking right under the nose of an unsuspecting USC student. It all started last Friday, while we were enjoying a nice stroll through the Nature Gardens. First, we checked out the Malaise trap that Brian and his staff set up as part of the BioSCAN project, which aims to survey the insect biodiversity here in Los Angeles. Then, we headed into the Nature Lab to see insects from this trap, and the 25 others that have been placed all over Los Angeles, being sorted.

As we got close to the demo table, Brian was suddenly transfixed. He'd seen something interesting on the screen that shows visitors the insects our scientists are sorting under the microscope. By some amazing coincidence, the USC student who was sorting a sample collected in Glendale, just happened to be looking at a phorid fly. Phorids, aka humpbacked flies, are the group of flies that Brian studies, and according to him, they are a mega-diverse family. How mega, you might ask? Apparently, there are estimated to be 40,000-50,000 species of phorid flies, and only 4,000 have been described by scientists so far. Wow!

But, it wasn't just any phorid fly. After taking a look through the microscope himself, Brian nonchalantly walks back over to me and said, "Yep, it's an ant decapitating fly." Whoa, what? I had no idea we had ant-decapitating flies (ADFs) here in L.A.! How could he have neglected to mention this exciting fact during all of our insect musings? Sure he's regaled me with stories of ADFs from Costa Rica and Brazil, always with devilish decapitating detail. But, he never mentioned we have phorids in the genus Pseudacteon, also known as fire ant decapitating flies, here in L.A. Fire ant decapitating flies do just as their name implies. When a female is ready to lay an egg, she locates an unsuspecting worker ant and injects her egg into the thorax. As the larva develops it migrates into the head capsule and molts a number of times. Through this entire process the ant behaves normally. However, just before pupation, the maggot begins to consume the tissue inside the ant's head, which causes the ant to act oddly, and soon after, to expire. The head falls off and the mouth parts are pushed out, so the oral cavity is clear. As the larva pupates, the adult fly emerges from the now-clear oral cavity of the ant. How's that for an alien ant birth? Later that day, Brian wrote an e-mail to the homeowner where the trap was located in Glendale: "Your backyard trap got something unusual- a phorid fly (the group of insects I study) of the genus Pseudacteon. The flies in this genus are all ant parasites, developing in the ant's head, and are referred to as 'ant-decapitating flies.' Usually, in suburban areas, the ant hosts of Pseudacteon are eliminated by the introduced Argentine ant, but you must have (or be close to) a healthy native ant fauna!" This, as Dr. Luis Chiappe, Vice President of the Museum's Research and Collections Department, put it, "is the power of science!" The presence of this parasite, allowed Brian to infer the presence of the host. If we went out to Glendale today, we'd likely be able to find native fire ants somewhere close by! And I know you all dying to join me on that adventure.    

(Posted by: Lila Higgins)

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