August 18, 2016
Wasp-mimicking beetle in the genus Necydalis found in Monrovia, CA. Photo credit: Kelsey Bailey
If you spot a brightly colored, slender, 1 inch-long insect in your yard, you might hesitate to get too close. It is not uncommon for residents of L.A. to come into contact with large wasps that have bright orange or yellow warning coloration, letting you know that they can sting if threatened. Colors can be misleading however, as you can see with this impressive longhorned beetle that was recently collected in Monrovia as part of the BioSCAN Project. The insect may have the same general shape (that characteristic thin wasp "waist") and bright orange body that screams out "I'm a wasp! Don't touch me!," but in reality it is completely incapable of stinging. This form of mimicry benefits the beetle as it deters potential predators from turning it into a crunchy afternoon snack!
August 16, 2016
Pacific Gaper Clam: A large, common bivalve that inhabits sandy areas of bays along an open coast, often buried a foot or more. Today it ranges from Humboldt Bay northern California to Punta Rompiente, Baja California Sur.
Asphalt soaked fossils are not new to the Hancock Park area of Los Angeles and most residents are already familiar with the iconic mammoths, saber-tooth cats, and dire wolves on exhibit at the La Brea Tar Pits and Museum that are between 11,000 and 40,000 years old. However, in 2014 during test excavations for a future Metro Purple Line Station at the corner of Wilshire Blvd. and Ogden Dr., a deposit of late Pleistocene marine fossils (120,000 to 300,000 years old) was excavated.
Big News for L.A.
The find made the front page of the Los Angeles Times and indicated that more fossils would likely be discovered as construction continues. What made this fossil collection unique from other marine Pleistocene deposits in the Los Angeles Basin is that the fossils are saturated with gooey asphalt much like the specimens collected from the La Brea Tar Pits. However, at 120,000 to 300,000 years old, these fossils are much older than those from the tar pits and were deposited much deeper. How did this occur? Asphalt migrated towards the surface along a buried fault, possibly the San Vicente Fault, from the Salt Lake Oil Field beneath Hancock Park. As it rose the asphalt encountered marine fossils in strata of the “San Pedro Formation” and saturated them completely. The asphalt eventually reached the surface where the tar pits ultimately formed.
A California Butter Clam found during Metro Purple Line construction. A large, common bivalve that lives in muddy/sandy areas of bays. Its modern range is from Kodiak, Alaska to Bahía Magdalena, Baja California Sur.
A Marine Fossil Bonanza
The 2014 discovery included a suite of invertebrates (animals without a backbone) that are indicative of a shallow-marine environment very much like that of modern Santa Monica Bay. In fact, large numbers of near-shore species such as the Pacific Gaper Clam (Tresus nuttallii) and the California Butterclam (Saxidomus nuttalli) indicate that the shoreline may have been in the Hancock Park area over 100,000 years ago! Over 60 species of mollusks, sea urchins and sand dollars, barnacles and crabs, worm tubes, moss animals, and encrusting hydrozoans were identified from this exploratory site that is 60 to 80 feet below street level.
One Extinct Species
With one exception all of these invertebrate species are still living. The single extinct species is a large Slipper Shell (Crepidula princeps). In 1970 paleontologists James Valentine and Jere Lipps reported a small assemblage of asphalt soaked marine invertebrates from a construction site just east of the current excavation. Unfortunately, the collection was lost, but field notes made available by Jere Lipps indicate that these two faunal assemblies are very similar. As subway construction proceeds westward it is anticipated that there will be a lot more of these marvelously preserved fossils unearthed for ongoing and future research.
So … over a 100,000 years ago the surf was indeed up in Hancock Park! Cowabunga dudes!
A tray of Pacific Gaper Clam specimens, ranging from juveniles to adults.
**Writing and photographs by Lindsey Groves, @Malacology Collections Manager.
Valentine, J.W. and Lipps, J.H. 1970. Marine fossils at Rancho La Brea. Science 169(3942):277-278, fig. 1.
August 12, 2016
Despite being the type of vegetable gardener who studies tomes on best practices, I have a hippy family that nurtures the welfare of tobacco hornworms (Manduca sexta). The big green caterpillars—considered major garden pests—feast and fatten like Henry VIII on the leaves, stems and fruit of the tomato plant. The caterpillars are masters of camouflage, blending into the dense, green foliage while clinging to the underside of leaves, and you often don't know that they're there until you spot their sizable dark droppings, the swift defoliation of your plant, or the mauled flesh of ripening tomatoes.
Caught in the act. Tobacco hornworm enjoying a black cherry tomato. Photo by: Candice Kim
You might consider the caterpillars, with their menacing red tail spike, unsympathetic garden inhabitants. The larvae, however, transform into the striking sphinx, or hawk, moth. Sphinx moths (family Sphingidae) are so large that species that hover while feeding on flower nectar have been mistaken for hummingbirds. Our local tobacco hornworms metamorphose into a mottled gray moth with an impressive four-plus-inches wingspan.
My family has raised numerous hornworms to their glorious adult form. Gently disengaged from our tomato plants, the caterpillars are given a new home in a small, pink-lidded terrarium, with a supply of fresh tomato plant branches and a moist bed of soil. Because they are mature caterpillars by the time we spot them and prepare their temporary plastic quarters, they are usually ready to pupate in the terrarium soil only a couple days after joining our household. Most have typically emerged weeks after pupating, but once we had a moth emerge ten months later.
Our hand-raised sphinx moth, released after 10 months' pupation in a terrarium on top of the refrigerator. Photo by: Karen Klabin
Recently, I found a tobacco hornworm on the back of a tomato plant only because I could actually hear it in battle with a sarcophagid fly. The parasitic fly, unappealingly called a “flesh fly,” is ovoviviparous, meaning it deposits its progeny—maggots—in, among other places, the flesh of other creatures. The maggots then eat their way out of the reluctant host, thereby, in the case of the caterpillar, killing it (an event most gardeners would welcome). I watched the fly buzz and dart around the caterpillar, which squirted a dark liquid and twisted and seemingly snapped at the fly to try to keep it at bay. After a few minutes of battle, the dauntless fly landed successfully on the caterpillar, presumably depositing its larvae. I left the caterpillar on the tomato plant to fulfill its martyrdom as a maggot buffet.
The perp up close. The sarcophagid fly takes a break from attacking the hornworm. Photo by: Martin Schlageter
After returning from a short trip, I examined the tomato plant and failed to find the hornworm itself but did find the evidence of its diligent employ: a number of perfectly ripe tomatoes marred by gnawed and moldy flesh. The tomatoes weren't salvageable. And so the thought of the hornworm being parasitized by the sarcophagid fly did not break my heart. Nor those of my hens, who enjoyed the ruined tomatoes.
The ladies enjoying a hornworm-ravaged tomato. Photo by: Karen Klabin
August 11, 2016
The orange spots on this Moorish Wall Gecko foot are not gecko bling. They are tiny parasitic mites that wedge between the gecko's scales to suck blood. Lizards often have mites, but rarely do I see infestations like this. These geckos are native to the western Mediterranean Region (southern Europe and North Africa), but I recently found an established population here in Southern California. Some of the geckos had as many as 286 mites, most of which were wedged between toes or on the soft skin around the eye (up to 52 mites around one eye!).
Do they impede the geckos from walking on walls and ceilings? This has not been well studied, but probably not. The incredible grip that allows geckos to walk on walls is caused by tiny hair-like structures called setae on the underside of the foot, and hardly any mites take up residence there.
That itchy feeling you have right now...sorry about that...
August 10, 2016
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)
August 9, 2016
Mulitcolored Asian ladybug, Harmonia axyridis, collected from the roof of Angel City Brewery in Downtown LA. Ladybug date night? Photo credit: Kelsey Bailey
A Curious Growth on a Ladybug
Sometimes I feel like I have seen it all when it comes to the bizarre happenings of the bug world. Like some sort of insect inception (insection?), there are insects that live on insects, insects that live inside other insects as parasites, and even parasites on the parasites of those insects! I see evidence of these strange phenonmena regularly as I sort samples of insects from Los Angeles, but recently I came across a ladybug that had something I had never seen before. On top of the hardened wing covers, which entomologists call elytra, were oblong projections that covered the beetle like a tacky orange shag rug. Were they eggs of a ladybug parasite? Or some sort of mite? I immediately asked our talented photographer, Kelsey Bailey, to take photos of this specimen so that I could share the image in hopes of unraveling the enigma.
A Sexually Transmitted Fungus
The astounding answer came from a colleague at the UC Riverside Entomology Research Museum, Dr. Doug Yanega. The mystery fuzz was identified as the parasitic Laboulbeniales fungus, which incredibly feeds off of internal vital fluids. This fungus is unlike any other; it is only found living on the exoskeletons of hard-bodied creatures like beetles and their kin, and must be spread by direct body-to-body contact. Fortunately for the fungus, some insects like to take it slow when it comes to mating, allowing for that direct contact needed for the fungus to spread. Certain ladybug species stay locked in copulation for a minimum of 30 minutes and as a group are known to have many different partners throughout their adult lifetime. These behaviors can benefit ladybugs in that they assist in successful sperm transfer and maximize genetic diversity, but they also give parasites ample time to hop ship from one ladybug lover to the other.
Seven spotted ladybugs, Coccinella septempunctata, mating via GIPHY
It Feeds on Blood!
The realization that the Laboulbeniales fungus, despite its flowery name, is essentially an insect STD, blew wide open my notion of what makes a fungus a fungus. While most fungi are important ecologically as decomposers and nutrient recyclers, Laboulbeniales are one of the most unusual, intriguing, and unfortunately poorly studied fungi. They do not form fruiting bodies, what most people know of as mushrooms, but consist only of a simple finger-like structure that attaches and bores into the exoskeleton. The insects’ version of blood, called hemolymph, contains nutrients that the fungus happily sucks up. This is the living version of a pointed straw that you pierce into a child’s juice box, but instead of fruit punch, in this case it’s beetle blood!
Macrophotographs of the Laboulbeniales fungus.
A Non-lethal Dose
Fear not for the life of the ladybug who has been shagged by the Laboulbeniales fungus! Moderate infections do not appear to be lethal to the infected individual. A study done on yet another ladybug STD, a sexually transmitted mite, showed that the ladybug’s life span was too short to succumb to the pressure of the parasite. In other words, they die of old age before the infections become serious. This ensures that future generations of ladybugs will continue to congregate and live out their free-love lifestyle in peace and harmony.
August 2, 2016
Los Angeles is a stunningly metamorphic place. A vast, industry- and people-dense metropolis, L.A. lives in the global psyche as the frontier of opportunity and personal transformation. Everything about L.A.—its geographic boundaries, the contours of its built environment, the languages and culture and impulses of its residents—is in a permanent state of flux. The city becomes nearly unrecognizable from one generation to the next.
Our planet is in a state of equally dramatic transformation.
The Earth is rapidly being reconfigured into sprawling urban centers, like L.A. According to the World Health Organization (WHO), “The urban population in 2014 accounted for 54% of the total global population, up from 34% in 1960, and continues to grow.” Interestingly, WHO notes that the growth is concentrated in less developed regions of the world.
For that reason, the May 20, 2016 edition of the journal Science was dedicated to our “Urban Planet.” The introduction to the special issue, titled “Cities are the Future,” describes the impact of global urbanization. “The implications are sobering. The land area needed to provide city residents with food, energy, and materials is expanding; this ecological footprint is often 200 times greater than the area of a city itself. The resulting carbon emissions, added to those from cities themselves, mean that urbanization is now the main driver of climate change.”
A “perspective” in Science’s blowout issue, written by Terry Hartig and Peter H. Kahn, Jr., and titled “Living in Cities, Naturally,” addresses some of the physical and psychological malaise that urban residents can experience when they are disconnected from the natural world. They also discuss an impact of urbanization that may be more subtle but far-reaching.
When city dwellers are divorced from nature and a sense of the richness of the natural world, they start to normalize environmental degradation in what Hartig and Kahn call “environmental generational amnesia.” “[P]eople do not feel the urgency or magnitude of problems because the experiential baseline has shifted.” In other words, to paraphrase Donald Rumsfeld, urban dwellers don’t know what they don’t know about environmental change. They have no real reference point. They can only measure changes to their natural environment based on vague memories of childhood experiences. “Providing opportunities for people to experience more robust, healthy, and even wilder forms of nature in cities offers an important solution to this collective loss of memory and can counter the shifting baseline,” Hartig and Kahn write.
L.A. Can Lead the Way
Greg Pauly, curator of herpetology and co-director of NHMLA’s Urban Nature Research Center (UNRC), grew up in a suburban neighborhood near San Jose, California. He spent his afternoons wandering the nearby hills searching for lizards. He also rescued and rehabilitated a menagerie of three-legged, no-tailed lizards that had been maimed by neighborhood cats. His early relationship with these lizards, and the acute awareness of the natural and unnatural environments which they navigated, spurred his desire to study and protect them.
“When my father was growing up in Pasadena, horned lizards were a common part of the landscape. That species is now entirely gone from the L.A. basin. At the UNRC, we’re trying to understand how species have responded to urbanization and how their distributions are changing.”
Once common, the majestic horned lizard is no longer found in the L.A. Basin. Argentine ants have displaced native ant species on which the horned lizard feeds. The well-camouflaged lizard above was recently photographed in Kern County. Photo by: Martin Schlageter
“Los Angeles is a biodiversity hotspot,” says UNRC co-director Brian Brown. “It’s an area of great diversity, but it is also under great threat. Through collaborations and access to scientific resources, UNRC is creating the world’s largest urban biodiversity survey. Our research can help inform urban planning policies to minimize impacts on native species.”
We are well past the era of boosters selling the young L.A. as a utopia of unbridled innovation, opportunity and wellness. And we are also beyond the bleak, Blade Runner-esque dystopian vision of L.A. that dominated in the latter half of the past century. Like all cities, Los Angeles, even at its urban core, remains a dynamic, living ecosystem. Understanding, protecting and promoting the region’s biodiversity is our next frontier.
If you’d like to be involved in efforts to document and protect L.A.’s biodiversity, check out our Citizen Science program. Or you can donate to the UNRC.
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!
July 19, 2016
Allison (Allie) Balthazor, a Gallery Interpreter at NHMLA, recently had a new family move in next to her apartment. Instead of a U-Haul, all they brought were a few sticks and twigs. Allie lives in an apartment complex in Burbank and not off the grid in a local wilderness, so of course her new neighbors were not humans. They were a mated pair of Mourning Doves (Zenaida macroura)!
Footage of female Mourning Dove guarding her nestling in the nest, seemingly unfazed by the urban sirens passing by. Video by Allison Balthazor.
Twigs and branches being set up by Allison’s new neighbor. Photo by Allison Balthazor.
Allie shares her entertaining story with us:
“The property manager was not happy about them moving in, and he wanted to kick them out. (Maybe it was because they didn’t sign a lease!) Of all the pest problems you can experience in an apartment, I’d much rather live with a Mourning Dove family than with bed bugs ANY DAY!
The doves first brought some twigs with them and stuffed them in the case above the fire extinguisher, then they formed them onto a little twig wreath. Shortly after, I saw one egg appear. The next day, when I came back from work, there was a second egg. The parents took turns incubating the eggs, and the chicks hatched, grew and fledged surprisingly quickly. The property manager was happy when they left. But his glee was premature. They returned not two weeks later, built another nest, and are raising a second family.”
Nesting on fire extinguisher at eye level at a semi-indoor hallway. Photo by Allison Balthazor.
Kimball Garrett, NHMLA’s ornithology collections manager, says that Allie’s observations are consistent with known Mourning Dove breeding patterns. They only need approximately 30 days between the initiation of the first and second clutches of eggs, and can actually lay new eggs while the first brood of offspring are still being tended. Which is why Mourning Doves are one of the most abundant species in the United States, with a population of 350 million.
Human parents, or soon-to-be parents, may be able to learn from these avian team players. The male and female doves work together to make sure their breeding is a success. The male chooses the territory, the mom finds the actual nest site, and the male gathers branches and twigs for the female to construct the nest. Both parents produce crop milk—a highly nutritious secretion from the lining of the doves’ crops—and they consume snails and bone fragments to aid in the production of the delicious baby bird formula.
Unlike the ubiquitous Rock Pigeon (or Rock Dove—otherwise known, and loathed, as our common domestic pigeon) that was introduced from Europe into North America in the early 1600s, Mourning Doves are a native dove species in Los Angeles. Pigeons and doves are part of the same taxonomic family (Columbidae). Species known as “pigeons” typically have a heavier build with shorter necks, and broader, more squared-off tails than doves. Interestingly, Mourning Doves are more common than Rock Pigeons inside the NHMLA Nature Gardens, though there are more Rock Pigeons in the surrounding buildings and open lawns.
Mourning Dove nesting in the NHMLA Nature Gardens. Photo by Allison Balthazor.
Doves and pigeons are the only birds, other than sandgrouse, that have the unique ability to suck and swallow water without lifting their heads. This may be an anti-predator defense, as they are ground-feeders and need to stay extra-vigilant.
Mourning Doves are typically recognized as the lighter colored and pointy-tailed pigeons with wings that whistle in flight. They are often confused with owls due to their cooing “hoo-OOOoo, hoo, hoo-hoo” call.
The only other common native Columbidae family member in the L.A. Basin is the Band-tailed Pigeon. Its distribution is centered in the foothills and forests, although many have colonized the suburbs and even downtown L.A. The native Mourning Dove, however, is possibly the most widespread bird in Southern California, which is impressive given how many bird species occupy the region.
A few non-natives are becoming increasingly populous. Introduced species that thrive in a new region are usually generalists (flexible diet, habitat preferences, and behavior). Those characteristics allow them to outcompete less flexible native species that have overlapping ranges and habits. Similar to the Mourning Dove, the Eurasian collared dove is an introduced species that has become widespread. One of the easy ways to distinguish between the two species is by looking for the distinctive black collar on the back of the collared dove’s neck. They are also stockier and much paler than Mourning Doves. Eurasian collared doves were accidentally released in the Bahamas in the 1970s and subsequently spread to Florida. Throughout the 1990s and into the early 2000s they spread rapidly across North America, including California. A separate introduction of collared-doves took place in Ventura in the early 1990s (Garrett et al. 2012).
Eurasian collared dove documented on iNaturalist by @nhmordenana.
Perhaps, one of the reasons dove species do better in our region is because they aren’t hunted. Mourning Doves are a highly hunted game bird in North America, but L.A. doesn’t have a robust hunting culture, nor is hunting even allowed within city limits.
You can now appreciate our common Mourning Dove wherever you go in L.A. If you see a dove, take a moment to appreciate its quirkiness, try to ID it, and send a photo to our L.A. Nature Map.
Garrett, K. L., J. L. Dunn, and B. E. Small. 2012. Birds of Southern California. R. W. Morse Company, Olympia, Washington. p. 219.
Mirarchi, R. E. and T. S. Baskett. 1994. The Mourning Dove (Zenaida macroura). In The Birds of North America, No. 117 (A. Poole and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists’ Union.
July 12, 2016
Jesse Brewer Park. Useful, if not exactly lovely. Photo by: Brian Brown
Across a small lane from the Museum lies Jesse Brewer Park, a modest, if thirsty, area of lawn, trees and playground equipment. Usually, there are homeless people encamped there, waking up in the morning as I arrive at work. I sometimes look at the park and think that it is an uninspired space compared to the Museum’s Nature Gardens, but it is surely better than concrete, providing much-needed play space for kids.
But what, I ask myself, does it provide for wildlife? Surely there must be some habitat, since the park has large, mature trees. Recently I walked across the road with camera in hand to see if I could find something interesting.
It didn’t take long. The sycamore trees along the east side are dotted with pupae of ladybird beetles, or ladybugs. Like all beetles, ladybugs have “complete” metamorphosis, with an egg, larva, pupa, and adult stage. There are no “baby” beetles that somehow grow into larger beetles; once an adult emerges from its pupa, it is done growing.
Yes, this is a beloved creature: ladybug pupa. Photo by: Brian Brown
Looking like some fabulously ornate shell, a ladybug pupal skin nested inside its bristly larval skin. Photo by: Brian Brown
I found a number of pupae decorating the trees, usually skirted with their spiky larval skins. Some of them looked a little different and might represent other species. Finally, I came across an adult, a still-pale-colored (from having just recently emerged) Harmonia axydris, the Halloween ladybug, so named by my friend John Acorn because of its orange color. It is an introduced species that has caused concern that it might be competitively excluding some native ladybugs, but in Jesse Brewer Park they are a welcome decoration on the sycamore trees.
Harmonia axydris, the Halloween ladybug. Photo by: Brian Brown
Find nature in your local park? Share your photos with us, so they can become data points for science. Use #NatureinLA to share on social media, or e-mail your observations to email@example.com, or upload them directly to iNaturalist using the free app.