October 20, 2011
Since it's October I decided to focus the rest of this month's posts on Halloween inspired themes. Wracking my brains for topics, I realized something I saw last week in the basement would fit the bill nicely. Flesh flies!Generally the Live Animal Program doesn't keep flesh flies but Shawna Joplin, Coordinator of Animal Care and Education, brought them in as a new food source for our spiders in the Spider Pavilion (open through November 6). The species we are keeping are grey flesh flies, Sarcaphaga bullata, which get shipped to us a pupa. After about a week and a half the adult flies emerge from the puparium and are ready for us to release into the pavilion.
Grey flesh fly pupae
Our adult flesh flies feeding on bananaFlesh fly emerging from its pupariumContrary to their common name, adult flesh flies don't feed solely on flesh. In fact they just as often eat nectar and other sugary items such as rotting fruit. All flesh flies in the family Sarcophagidae are larviparous, which means they incubate eggs internally and then seemingly give birth to live young, or maggots. It is the place of "birth" that gives these flies their common name—they are deposited on any available dead flesh! In fact these flies are some of the first visitors to roadkill, discarded innards, and even murder victims. Putting these flies to work, forensic entomologists have painstakingly studied their lifecycle, so they can assist Crime Scene Investigators in determining time of death. Because they rapidly discover a body and their development times are predictable under particular environmental conditions, the time of death can be calculated by counting back the days from the life stage of the flies found living on the body.Next time you feel like seeing these maggots in person, just do what some of our Adventures in Nature campers have done—put out a piece of store-bought liver and wait for the maggots to show up! WARNING: This is smelly, messy work! Lots of other species of flies, beetles, and other creatures are likely to show up too. Are you prepared? Happy Early Halloween!
October 13, 2011
Yesterday afternoon myself and number of other staff members braved the heat to continue our survey of North Campus insects. On the heels of last week's Gulf Fritillary discovery, I found the site's first Monarch butterfly caterpillar, Danaus plexippus!
Monarch butterfly caterpillar
As soon as I saw the caterpillar I knew it was a Monarch: There isn't another caterpillar in our area with such yellow, black, and white banding. Also, the caterpillar was found on a narrow-leaved milkweed plant, Asclepias fascicularis, which is one of the food plants of this well-known species.
Based on its size, this caterpillar is in the second to last caterpillar stage (4th instar). Over the coming weeks it will molt to the last and final stage (5th instar), and then turn into a chrysalis. In time for its fall migration, the adult Monarch will emerge and make its way to an overwintering site somewhere along the coast.
In the coming years I hope to tag and track the adult Monarchs that emerge in the North Campus, so we can determine the exact location(s) of our Monarchs' overwintering site(s). Tagging Monarchs is an easy process that in no way hurts the butterflies. The adults are collected with a net and then carefully held while a small sticker (approximately 2% of the butterflies weight) is attached to the hind wing of the butterfly. The butterfly is then released and flies onto its overwintering site. When the Monarchs dies the following spring (after mating) the tags are hopefully retrieved and we can answer the question, where do our North Campus Monarchs overwinter?
Demonstrating how to handle a Monarch for tagging
October 5, 2011
The last few weeks I have been spoiled with bloggable stories, but this week I needed inspiration. I took a stroll out to the North Campus to see what I could find, and was excited to happen upon the first North Campus caterpillar.
The caterpillar I found was in the last and final "J stage" of its larval lifecycle, just about to pupate.
Easily recognizable, Gulf Fritillary caterpillars are striped and spiny.
24 hours later the caterpillar had metamorphosed into the pupal stage, aka chrysalis.
If you look close, you can see the developing wings.
This pupa is a Gulf Fritillary butterfly, Agraulis vanillae, native to Mexico and the southeastern United States where its passion vine food plants are also native. However, this species is now very common to our region because of all the passion vines that have been planted in yards, parks, and also in the North Campus! The species of passion vine I found the caterpillar on was Passiflora 'Lavender Lady' cultivar, which is a cross between P. amethystina and P. caerula.
Typical alien-looking flower of passion vine, 'Lavender Lady' cultivar.
If you want to encourage these butterflies in your own yard, try planting a few passion vines of your own. Here is a list of the other passion vines we plan on planting in the North Campus:
September 12, 2011
When Tim Bovard, the Museum's taxidermist, told me about getting stung by wasps on the fourth floor patio, I had to investigate, especially since I sometimes eat lunch up there. During a much needed afternoon break from my computer, I went in search of the offenders. What I found on my afternoon foray were some large and impressive nests, definitely worthy of a blog entry. So of course I asked Sam if he would take pictures for me, and I went to work identifying them.
Common paper wasp nest, Polistes exclamansThe species living on our patio are Common Paper Wasps, Polistes exclamans, which have a widespread distribution through much of the southern United States. These insects construct a papery nest from fibers they gather off dead wood or plant stems. Next time you see a paper wasp on a wooden fence realize it might be chewing off tiny pieces of wood which they will mix with their own saliva to make paper! The nests are umbrella shaped and generally built under eaves or porches, or in similarly sheltered locations. Unlike yellowjackets and hornets, paper wasp nests are not enclosed in a papery shell, which give a really good view into the individual cells.
A view into a brood chamber, can you see the larva?Sam was also able to get some great video footage of the wasps at work. In an effort to provide the best video documentation ever, Sam nearly sustained a few stings himself. Luckily the wasps went for the video camera instead!
August 5, 2011
A couple weeks ago we had the second round of our North Campus insect survey. Fifteen Museum staff tromped around the North Campus to see what insectuous wonders we could collect. Although we found some notably large specimens, the largest being a 3-inch bird grasshopper (Schistocerca sp.), the most interesting find was actually something a lot smaller. Much, much smaller in fact: a minute fig wasp about 2 millimeters in length!
Female Fig Wasp, Pleistodontes sp.
Fig wasps belong to the wasp family Agaonidae and as their name implies, they have a life history intricately linked with fig trees, family Moraceae. In fact fig trees can not produce figs without the wasps, and the wasps can't reproduce without the figs! The way this mutually beneficial relationship works is quite astonishing, especially if you take a journey to the core of a ripening fig!
Journey to the Center of the Fig
It all starts when a mature female fig wasp enters the synconium (an immature fig if you will) through its natural opening, called the ostiole. This sounds really easy when you think how small these wasps are, but nature has not made it easy on the fig wasp, as the opening is actually too small for the adult wasp to enter without damaging herself. It's so small that the fig wasp often loses her wings and much of her antennae as she struggles through the opening. To enable passage through the ostiole, the underside of her head is also equipped with spines that help to get a grip as she's going through the hole (see image above).
Once inside the synconium she passes over the fig's female flowers and inadvertently deposits pollen from the male flowers of her original host tree. She then deposits her eggs in the cavity. Her business being done, she dies. The Pleistodontes fig wasp we found is, interestingly, not a pollinator of edible figs. Instead, it is a pollinator of ornamental figs which can be found in backyards and parks across Los Angeles.
Once pollinated, the fig fruit begins to develop, consuming the wasp's dead body in the process. The eggs hatch and the larvae consume small parts of the developing fig. After the larva eat enough fig, they pupate and finally emerge as adult male and female wasps. The wingless male wasps have only two functions to perform in their short lives—to mate and to escape! Finding a mate inside the fig isn't too difficult for the male wasp as all of his sisters are stuck inside the fig with him (remember how small the ostiole opening is). After he mates with at least one of his siblings (or offspring from another wasp), he begins digging a tunnel to exit the fig. This tunnel is the escape route that the female wasp uses to exit the fig, but not before she picks up pollen from the male flowers. This pollen will eventually pollinate the developing fig she visits to lay her own eggs in, and thus the life cycles of both fig and fig wasp continue.
All I can say is WOW! Nature is weird, wonderful, and so cool!
Thanks to entomology curator Brian Brown for identifying and photographing the wasp.
June 7, 2011
We here at the Museum really like bees, so much so that we are building them a hotel! This hotel will contain over 200 deluxe suites for native bees. We've specifically designed the hotel to accommodate various solitary bees found in L.A. We'll keep you posted as we see what moves in. Thanks to exhibit fabricator, Jerome Brown, the hotels are nearly ready to be put out in the Butterfly Pavilion yard.
Cedar log with pre-drilled bee holes
It seems that other bees have heard how luxurious our accommodations are and stopped by to check them out! Last Friday we got reports of a European honey bee, Apis mellifera, mass in one of the Magnolia trees on the west side of the Museum. Brent "the Bug Guy" Karner, went to check it out and took this picture below, thanks Brent!
Honey bees, Apis mellifera
This mass of bees is called a swarm and likely contains over 1,000 bees! Swarming is a natural part of a honey bee colony lifecycle and provides the colony with a means of reproducing. This is the season for seeing swarms, as colonies have increased in size and no longer comfortably fit in their nests. In preparation for this big move, the old queen lays eggs that will turn into new queens and she takes off with about half of the colony to find new a new home. If you come across a honey bee swarm, don't worry, since they are all adults with no nest to defend, they are not quick to sting.
May 26, 2011
I know you've seen a lot of still images from the Black Phoebe, Sayornis nigricans, nest, but I just had to share this footage. Honestly, it is too good not to post. At the beginning of the video you'll see one of the adults (hard to tell if it's the mom or dad, they both help to care for the nestlings) feeding a European Honey Bee, Apis mellifera, to one of the young. This in and of itself is pretty awesome to see, but it gets even better! Remember the Bushtit post? I told you all about how some species of birds produce fecal sacs, to make it easier to keep the nest clean and disease free. Well, Black Phoebes also produce fecal sacs, and this video gives you an insight to this behavior. I'll let you judge for yourself whether you think it's gross, cool, or just plain interesting.
April 22, 2011
As mentioned in an earlier post New Fly for North Campus, we've been trapping insects on the North Campus for a while now. This week however, is a milestone for NHM as we held our first quarterly insect survey. Our aim was to go after the insects that our Malaise trap wasn't sampling, like large flying insects such as crane flies and bumble bees and ground dwelling insects like earwigs and beetles. Since this was our first time and the site is still an active construction zone, we limited participation to NHM staff and partners. As the specimens get prepared and sorted, I'll keep you all up to date on the species we identify.
Brent "the bug guy" Karner demonstrates proper use of a
beating sheet to our USC partners.
Brian Brown showing off his aspirator (aka pooter) skills.
Look closely, I swear there's an insect there!
A common insect, but nonetheless an impressive catch.
Female carpenter bee in the genus Xylocopa
Special thanks to Cordell Corporation for allowing us to access the site.
April 5, 2011
Insect Trapping To better understand the insect diversity of the North Campus, we've started surveying the insect fauna on the construction site. A few months ago, Dr. Brian Brown, the Museum's Curator of Entomology, set up a Malaise trap. This type of trap is commonly used by entomologists to capture small flying insects, and so far we've collected hundreds! One of the coolest (at least in Brian's opinion, and now mine too) is the Boatman Fly.
Dr. Brian Brown setting up a Malaise trap in his backyard (yes Entomologists take their work home with them too!)The Boatman Fly, Pogonortalis doclea, is a small (1/4 inch) fly originally from Australia. It was first recorded in California in 1963, and to date has not been recorded in any other state. These flies are quite striking in appearance with their brightly colored eyes and highly patterned wings. Males of the species are often seen walking over leaves waving their wings in display, which look very much like a person rowing a boat, hence the name.
Boatman Fly, Pogonortalis doclea
March 23, 2011
Inter-whats? Interactives are what we at the Museum call cool gizmos and hands-on experiences in exhibits. We are planning to have some really great outdoor interactives in the North Campus. Right now we are getting ready to test prototypes in the Butterfly Pavilion yard. I'll post more about them when the Pavilion goes live on April 8, but as a teaser, check out this article posted on LA County Board of Supervisor, Zev Yaroslavsky's website.
This is the first round prototype of our proposed Butterfly Counter. Stay tuned for the version that visitors will try out in the Butterfly Pavilion.