Bloodsucking Flies Terrorize Pigeons in Gardena

January 27, 2014

Photograph of dorsal, lateral and ventral views of Pseudolynchia canariensis.

Pseudolynchia canariensis. Photo: Kelsey Bailey.

This week, the BIOSCAN team brings you… a squashed fly from Gardena?! This may be what it looks like but we are excited to share with you our first specimen from the fly family Hippoboscidae, commonly referred to as louse flies. This particular species, Pseudolynchia canariensis, is a parasite on pigeons and doves, a bird louse fly. The BioSCAN team was thrilled to see this specimen appear in one of the site samples, not only because these flies are relatively rare, but because many flies in this family are flightless, and some are without wings at all. Obviously, wingless species are unlikely to be caught in a Malaise trap designed for flying insects, so we were lucky to catch this flying species. The unusual appearance of this fly tells us a lot about its life history. The flattened body (yes, it’s supposed to be that way, it hasn’t been squashed) allows the fly to slip between the feathers on its host, while keeping a low profile. Anyone that has been hiking locally may have dealt with ticks on their own body or that of a companion animal — ticks use that same flattened body shape to make themselves harder to remove. A flattened body shape (scientists refer to this as being dorso-ventrally flattened) helps prevent a parasite, in this case a fly, from being dislodged while it utilizes its food source — host blood. Feeding on the blood of another animal can be tricky business. Our BioSCAN scientists speculated that this fact (coupled with fly "old age") may have contributed to this specimen's tattered wings; perhaps the host tried to dislodge the feeding parasite and damaged it. One look at the view from below and it becomes clear that the sclerotized proboscis (fancy entomology words for "tough mouthpart") is undoubtedly painful; we don’t blame the bird for trying to get rid of it! Unfortunately for the pigeons, getting rid of these flies is not as easy as simply brushing them off. If you notice, the flies have long, curved claws on their feet. The last segments of insect legs are called the tarsi, and those claws are called tarsal claws. On most insects, these claws are small innocuous hooks — used for clinging to normal substrates. In these parasitic hippoboscids, however, these claws are enlarged with a pronounced curve to allow the fly to cling to its host — ouch! So where did these flies come from? Originally, this species was found in the Old World tropics and subtropics, but today they have spread virtually worldwide on domestic pigeons and doves. Despite this wide range, we rarely see them — they spend most of their time flying around attached to their avian hosts. So rest assured, for as ominous as this bloodsucking fly may seem, they are solely interested in bird blood, not yours.


(Posted by: Emily Hartop )


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Second Ant-decapitating Fly Found in Glendale

January 13, 2014

Our scientists found another species of ant-decapitating fly in Glendale, Pseudacteon amuletum!

Pseudacteon amuletum. Photo credit: Phyllis Sun

Here's an account of this tiny, yet impressive fly, by Lisa Gonzalez, one of our BioSCAN entomologists:

"For those of you who missed Lila’s exciting account of the moment Dr. Brian Brown first spotted an ant-decapitating fly in one of our BioSCAN samples as it was being sorted in front of our visitors in the Nature Lab, please enjoy this post. As Lila so eloquently described, ant decapitating flies are tiny but mighty little phorid flies that lay their eggs inside of the bodies of, you guessed it, ants. Many of these specialized flies have been the focus of our Entomology Department’s research as conducted in other, more tropical locales, so it may come as a surprise to hear that we have these incredible phorids right here in L.A. These parasitoids (a term we use to describe organisms that eventually consume and kill their host) will not just lay an egg in any ant they come across, but instead target a particular species.

Pseudacteon californiensis. Photo credit: Kelsey Bailey

For instance, Pseudacteon californiensis, the first ant decapitator to turn up in a BioSCAN sample, preferentially seeks out the native velvety tree ant, small ants with an orange thorax that nest beneath bark and in tree cavities. Some ant decapitating flies, like zombie hunters, “aim for the head,” but P. californiensis has been observed hovering over the abdomens of velvety tree ant workers where they appear to “lift” the abdominal segments to insert an egg into the host. The larvae must then travel towards the head, making their way through the occipital foramen (the very narrow opening containing the connective tissue between the thorax and head), to complete their development in the head capsule, which eventually is separated from the body by enzymes released by the developing maggot.

Our second Pseudacteon discovery from the same site in Glendale is P. amuletum, named from the Latin word for amulet due to its distinct horseshoe shaped oviscape that is reminiscent of a charm or pendant. One may also infer a deeper meaning of the name beyond shape but also of function: amulets can protect, and this species of Pseudacteon is important as a form of biological control against fire ants. A close relative of P. amuletum has been used to help control the spread of the imported fire ant Solenopsis invicta due in part for its rate of parasitism, but mainly because of how it affects the ant’s behavior. Solenopsis ants assume a very strange position when they detect Pseudacteon flies by lifting up their bodies and tucking their abdomens under and forward into a “C” shape with the same incredible skill of a Cirque de Soleil contortionist. It is believed that this helps protect the abdomen from egg invasion, but the trade-off is reduced foraging by the ant, which puts it at a disadvantage in relation to other more industrious, less preoccupied ant species. In this way, Pseudacteon contributes to a reduced fire ant population, which is greatly appreciated by those who know the alarming pain of a fire ant sting."

I don't know about any of you, but I can't wait to hear if we find a third species of ant decapitating fly. For breaking news on what they're finding in the other BioSCAN traps, check out their blog.


(Posted by: Lisa Gonzalez)


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Second Species of Ant Decapitating Fly Found in Glendale!

January 9, 2014

For those of you who missed Lila’s exciting account of the moment Dr. Brian Brown first spotted an ant decapitating fly in one of our BioSCAN samples as it was being sorted in front of our visitors in the Nature Lab, please enjoy this post.  As Lila so eloquently described, ant decapitating flies are tiny but mighty little phorid flies that lay their eggs inside of the bodies of, you guessed it, ants.  Many of these specialized flies have been the focus of our Entomology Department’s research as conducted in other, more tropical locales, so it may come as a surprise to hear that we have these incredible phorids right here in LA.  These parasitoids (a term we use to describe organisms that eventually consume and kill their host) will not just lay an egg in any ant they come across, but instead target a particular species.

Pseudacteon californiensis. Photo credit: Kelsey Bailey

Pseudacteon californiensis. Photo credit: Kelsey Bailey

For instance, Pseudacteon californiensis, the first ant decapitator to turn up from one of our two BioSCAN sites in Glendale, preferentially seeks out the native velvety tree ant, small ants with an orange thorax that nest beneath bark and in tree cavities.  Some ant decapitating flies, like zombie hunters, “aim for the head,” but P. californiensis has been observed hovering over the abdomens of velvety tree ant workers where they appear to “lift” the abdominal segments to insert an egg into the host.  The larvae must then travel towards the head, making their way through the occipital foramen (the very narrow opening containing the connective tissue between the thorax and head), to complete their development in the head capsule, which eventually is separated from the body by enzymes released by the developing maggot.

Pseudacteon amuletum. Photo credit: Phyllis Sun



Pseudacteon amuletum. Photo credit: Phyllis Sun

Our second Pseudacteon discovery from the same site in Glendale is P. amuletum, named from the Latin word for amulet due to its distinct horseshoe shaped oviscape that is reminiscent of a charm or pendant. One may also infer a deeper meaning of the name beyond shape but also of function: amulets can protect, and this species of Pseudacteon is important as a form of biological control against fire ants.  A close relative of P. amuletum has been used to help control the spread of the imported fire ant Solenopsis invicta due in part for its rate of parasitism, but mainly because of how it affects the ant's behavior. Solenopsis ants assume a very strange position when they detect Pseudacteon flies by lifting up their bodies and tucking their abdomens under and forward into a "C" shape with the same incredible skill of a Cirque de Soleil contortionist. It is believed that this helps protect the abdomen from egg invasion, but the trade-off is reduced foraging by the ant, which puts it at a disadvantage in relation to other more industrious, less preoccupied ant species. In this way, Pseudacteon contributes to a reduced fire ant population, which is greatly appreciated by those who know the alarming pain of a fire ant sting.  Although Pseudacteon have been recorded from LA before, they have become increasingly rare as their native ant hosts are pushed out by the ubiquitous Argentine ant, an introduced species that thrives in altered urban habitats, is not a picky eater, and succeeds by teaming up with sister ants from other colonies, joining forces against native ant species.  Knowing that the presence of these flies indicates a healthy population of 2 species of native ants makes this current find from one of our BioSCAN sites very impressive!  


(Posted by: Lisa Gonzalez )

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New Year: New Bird

January 3, 2014

"175," responds Kimball Garrett, the Museum's ornithology collections manager and resident bird nerd, when someone asked him how many birds he's documented around the Museum. In the last few days of 2013 Kimball checked off another bird that had never before been documented in Exposition Park, this brought Kimball's ever growing list to its current pinnacle.

Kimball behind the scenes in Ornithology

Although Kimball has been keeping track of birds in Exposition Park for 30 years now (WOW), this is nothing compared to his track record for Los Angeles. Kimball grew up in the Hollywood Hills where his parents had a bird feeder in their backyard. As a teenager Kimball would explore further and further afield, all the while documenting his bird observations in a journal.

Here's one of my favorite stories as recounted recently by Kimball:

"Growing up just a stone’s throw from Griffith Park’s Brush Canyon, I regularly escaped into that nature-filled canyon as a young teenager.  Among my many memories of watching birds and other wildlife in that area, one stands out in my mind. Winding my way up a narrow trail in the canyon bottom, not far below what I called “the waterfall” (I doubt it was more than about 8 feet high, but it seemed impressive at the time), I came around a bend and staring down at me from a dead oak snag was a King Vulture! Menacing, big, and very much out of place.  I assume this bird had escaped from the Los Angeles Zoo (just a couple miles north, over Mount Hollywood), and I couldn’t have known then it portended an interest I would develop in the non-native bird species (including parrots, mannikins, and doves) that are now among our most commonly encountered birds in urban habitats in the region."

Unlike the out of place vulture, the bird Kimball found on December 27 is a not that uncommon in our region. It was a Golden-crowned Kinglet (GCKI), Regulus satrapa, flitting around in a deciduous tree next to the pond. Unfortunately the bird was too fast for Kimball, and he was not able to snap a recognizable photo. However, he recorded the find and went back to his office. When he checked his Exposition Park bird list, he found that this was the first sighting of a GCKI! Though according to Kimball, we've had lots of sightings of its very close cousin, the Ruby-crowned Kinglet, Regulus calendula, which "is a common fall migrant and winter visitor to the park." In comparison the GCKIs are "scarce and irregular winter visitors to the lowlands of Southern California; this has been a better than average winter for them in the region."

This is what a Golden-crowned Kinglet looks like, photo courtesy of Dick Daniels.  

Maybe you can spot your own GCKI if you go out birding this weekend! Or if you are a novice, you could join a FREE L.A. Audubon bird walk this weekend and get some help.

Happy Birding in 2014!

 

 


(Posted by: Lila Higgins)


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Twelve Days of Los Angeles Nature: 2013

December 23, 2013

Let's celebrate another year of L.A.'s AMAZING BIODIVERSITY. The benevolent blogger that I am, here are your gifts:

Twelve Rattlers Rattling

Eleven Potter Wasps Piping

Ten Flies Decapitating (decapitating ants that is)

Nine Dragons Dancing (in the L.A. River)

Eight Mantids a Milking

Seven Planarians a Swimming

Six Lizards a Laying

Five Foxes Ring-ding-ding-ding-dingeringeding!

Four Glowing Worms (yes, they're glowworm beetles)

Three French Opossums

Two Turtle Newts

and P-22 in the Hollywood Hills

Here's to another year full of amazing Los Angeles nature discoveries!

*P-22 image courtesy of the Griffith Park Connectivity Study

 


(Posted by: Lila Higgins)

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California Holly: How Hollywood Didn't Get its Name

December 18, 2013

In Nancy Dale’s 1986 epic tome of Southern California native plants, Flowering Plants, she has this to say about Toyon — aka California Holly, Christmas Berry, or, if you’re a botanist, Heteromeles arbutifolia:

“It is thought that masses of this native shrub growing on the hills above Hollywood gave the community its name.”

This idea of floral origins for Hollywood is romantic. It’s also not true. Hollywood got its name for a much more mundane reason: someone wealthy liked the sound of it.

Toyon on Los Vaqueros Watershed Miwok Trail, photo by Miguel Vieira

In 1886, Harvey Henderson Wilcox, a rich prohibitionist from Kansas, and his wife, Daeida, purchased 120 acres of apricot and fig groves near the Cahuenga Pass at $150 an acre. Harvey, an inveterate businessman, realized he could make a lot of money by subdividing the land and selling the lots for $1,000 a pop. And so the Wilcox subdivision, as Hollywood was then known, was born.

A year later, on a train journey back to Ohio, Daeida Wilcox befriended a fellow wealthy traveler who just happened to own a fine estate in Illinois. Its name was Hollywood. The story goes that Daeida was so taken with the name that upon her return to California she encouraged Harvey to apply the name to their property. On February 1, 1887, the name was immortalized when Harvey filed a subdivision map to the Los Angeles County recorder's office, with the name “Hollywood.”

The Wilcox map of Hollywood-courtesy of the USC Libraries, California Historical Society Collection

But long before Daeida’s chance encounter and the installation of an enormous “Hollywoodland” sign, Toyon — or California Holly — was growing in the Hollywood Hills. These shrubs and the brilliant red berries that adorn them have been growing in Southern California for hundreds, if not thousands, of years. We’re not quite sure how far back they go: Scientists at the Natural History Museum, where I work, haven't found any in the La Brea Tar Pits yet, so it seems they’ve been here less than 10,000 years.

Toyon and Hollywoodland sign, 1937-courtesy of the Los Angeles Public Library photo collection

Before the Europeans showed up, the indigenous peoples of the area used Toyon for food, medicine, and tools. Making use of a plant isn’t unusual, but this plant’s name is. According to California Native Plants for the Garden (co-authored by the Natural History Museum's director of the nature gardens, Carol Bornstein), "Toyon is the only California native plant that continues to be commonly known by a Native American name." Toyon was the name given by the Ohlone people, and it stuck.

Two years ago, we planted about 25 Toyon in the Natural History Museum’s new Nature Gardens. Toyon are a mid-sized shrub in the rose family and can grow up to 20 feet; ours are now standing tall at a stately 10 feet. We knew they would fill in the garden pretty quickly, and provide great cover for many birds, mammals, and insects we wanted to attract.

In early summer their showy white flowers are magnets for native pollinators, which help to produce the bright red fruits that catch our attention at this time of year. If you cut open a berry—more technically known as a pome—the inside looks a lot like the core of an apple, and birds love them. Last year a large flock of Cedar Waxwings, Bombycilla cedrorum, descended on our mini Toyon grove. One of our gardeners noted that it only took these birds a matter of two weeks to clear out every last morsel.

Thankfully, there’s plenty of Toyon to go around as the shrub ranges all the way south into Baja California and north into the Sierra Nevada.

To Angelenos of the early 1900s, Toyon was better known as California Holly. The shrub closely resembles another winter evergreen, European Holly, Ilex aquifolium. Both have green leathery leaves with spiky edges and bright red berries that fruit in winter, and consequently were used to adorn people's homes as yuletide decorations. Lore has it that over-harvesting of the berries in the early 1900s led to a California state law outlawing the gathering Toyon on public lands. I couldn't find any evidence for this, but the story is repeated in many places, including on Wikipedia's Toyon entry.

Is California Holly our state’s most apocryphal plant? Perhaps. In 2012, it also earned the distinction of being named L.A.’s official native plant by the City Council. But we remain lucky that it ultimately wasn’t a neighborhood namesake. Can you imagine a huge sign over our city that reads TOYONWOOD? No, neither can I.

 

 

 

 

 

 

 

 

 

 


(Posted by: Lila Higgins)


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Botfly Found in Los Feliz

November 27, 2013

Much to the BioSCAN team’s excitement, we collected our first specimen of a large bodied fly that is infamous for its bizarre life history. Botflies are a group of flies in the Family Oestridae that are obligate parasites on mammals; the only way for their larvae to develop is to feed inside the bodies of their host. For those of you that have heard of botflies before, you might be familiar with horrifying tales of people who have traveled to the tropics and have been infested with a maggot (or multiple maggots!) that can reach an inch in length when fully grown.  That particular botfly, Dermatobia hominis, has been dubbed the “human botfly” for infecting humans, including one Entomology staff member, but in truth the fly does not target human beings (which would be foolish considering our strong ability to remove parasites from our skin)  nor does it really choose a particular host at all! Rather, the female botfly of this species attaches an egg to the underside of a mosquito’s abdomen in hopes that the mosquito will find a warm mammal to feed on — a cow, deer, or the occasional human being — so that the larva can emerge from the egg and bore into the skin where it will develop.

Photo credit: Kelsey Bailey

Photo credit: Kelsey Bailey

But there is no need to panic: the botfly found at one of the BioSCAN sites in Los Feliz is the California rodent botfly Cuterebra latifrons, which specializes in parasitizing the Dusky-footed wood rat, Neotoma fuscipes. This large, exquisite fly, with its white tufts of hair and shiny black and white Rorschach  patterned face, is not harmful to humans, but is certainly a wood rat’s nightmare. Females lay their eggs in the wood rats nests which hatch upon stimulation from movement and heat given off from the rat’s body.  The larvae then develop in the skin of the rat, which can have devastating effects to an individual rat if infested in high enough numbers. In contrast,  some species of botfly are ingested as their hosts groom themselves and develop inside the digestive track, and others, like the “snot bots” (one of my personal favorite nicknames for any group of flies), hover around the nostrils of their host, take aim, and shoot live larvae right up the nose!  We should appreciate that our California rodent botfly is a little more refined.


(Posted by: Lisa Gonzalez )

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What Does the Gray Fox Say?

November 26, 2013

A few days ago, Miguel Ordeñana, NHMer and local biologist working on the Griffith Park Connectivity Study, captured images of the elusive gray fox, Urocyon cinereoargenteus. Fortunately, I'm able to speak fox (growing up on a farm in England gives you certain skills), and have, through the magic of Photoshop, been able to translate his "Ring-ding-ding-ding-dingeringeding's" and "Fraka-kaka-kaka-kaka-kow's" into English.

*If you have no idea what the heck I'm talking about, you may want to check out Ylvis' sensational internet hit, "What Does the Fox Say?" Sure the fox they are talking about is most likely the red fox, Vulpes vulpes, but hey, I think you'll get the idea!

This is what the gray fox says:

All kidding aside, this is great news. According to Miguel, it is only the third time he's captured images of gray foxes in L.A., after almost two and half years of camera trapping! Why is this?

Mostly, it's because there just aren't many living in urban Los Angeles. They've been documented in the Baldwin Hills, on a golf course in South Los Angeles (not too far from the Museum), and in both Elysian and Griffith parks. Miguel, and other scientists studying urban carnivores, note that they "seem to be finding pockets of habitat that have enough resources, tree cover, and relatively low densities of coyotes." Even though gray foxes are very adaptable due to their small size and omnivorous diet, the larger, more social and aggressive coyote seems to have won out in the local wild dog war.

But, they're out there as Miguel's camera traps can attest, they're just pretty secretive. Not only are they mostly nocturnal, they also take to hiding while at rest. This can be in their underground den, in your backyard brush pile, or even up a tree! Gray foxes are one of the few Canids that can climb trees! By rotating their forearms, they can hug the trunk of a tree and propel themselves up the trunk with their hind legs. They've been known to scale heights of up to 60 feet, and sometimes they even build dens in the leafy reaches. How's that for vertical living in Los Angeles?

Learn more about our local gray foxes at Urban Carnivores.

 

 


(Posted by: Lila Higgins)


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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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Oak Wasp Galls

October 31, 2013

Let me introduce you to a tiny parasitic wasp that makes a unique nursery for its offspring. Meet the Oak Gall Wasp:

To construct her nursery, female Oak Gall Wasps employ a not-so-subtle subterfuge. Instead of working to find and construct a nest of her own, the wasp turns to the mighty oak and bends it to her will!

Eggs are gently inserted into the flesh of the oak's limbs and cause the area to swell. These deformaties are better known as galls, and help to protect and feed the developing wasp larvae that hatch inside. Although they are sometimes referred to as plant tumors, these growths are not harmful to the oak. Galls made by this particular wasp, can grow to the size of a small babies fist, and to the untrained eye look like apples. Therefore, they are often referred to as oak apples. What if one were to pick said oak apple and take it into their office? What would happen?

This is exactly what Carol Bornstein, Director of the Museum's Nature Gardens, did two weeks ago. Though Carol knew exactly what she was plucking from the Valley Oak, Quercus lobata, in our Nature Gardens, she ended up getting a bit more than she bargained for. A few days later—in the middle of a meeting no less—an unsuspecting Museum staffer, saw a tiny wasp skittering over her desk. Being a diligent worker, he quickly scooped the tiny insect into a handy vial (who doesn't go to meetings with vials in their pockets?) and brought it to my office.

Needless to say, I was excited! I've been waiting for a gall to grow on our oaks since they were planted two years ago. With a little sleuthing, I was able to find out the exact identity of our little waspy. Valley Oaks are often afflicted with galls of two varieties, those that look like apples, caused by the Cynipid gall wasp, Adricus californicus, and others that looks like Hershey Kisses, formed by A. kingi. Here's the gall in question:

It doesn't take Sherlock Holmes to figure out which species we have...Andricus californicus! So, now it's your turn. Go out and find some unsuspecting oaks and start looking for galls. If you get truly inspired, you might want to purchase the Field Guide to Plant Galls of California and Other Western States, because then you'll be able to start going on adventures looking for everyone of the 300 species covered. Its a gall new world!

 

 

 

 

 

 

 


(Posted by: Lila Higgins)


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