September 26, 2012
I just got this e-mail from our Curator of Entomology, Brian Brown. "I asked Entomology Volunteer Franesca Zern to concentrate on identifying true bugs from the North Campus Malaise trap. She just identified (through her own research) a new record for Los Angeles County, a mirid plant bug called Coridromius chenopoderis. This tiny, 2 mm long Australian bug feeds on plants, including beets and spinach, but is considered unlikely to be a pest. According to our colleagues at L.A. County Agriculture, this is the first report from here, although it is also known from farther south in California." Photos of the bug taken by Inna Strazhnik:
But that's not all! Brian left Museum staff with this interesting tidbit: "One interesting thing about these bugs is that they have traumatic insemination, like bed bugs. I won't broadcast the details, but yes it is as kinky as it sounds!" Although Brian won't broadcast the details, I will! Traumatic insemination, aka hypodermic insemination, is a mating practice employed by some kinky invertebrates, bed bugs being the most notable. The male insect pierces the female's abdomen with his sword-like penis and injects sperm into the abdominal cavity. The sperm diffuses through the hemolymph (insect blood) and eventually reaches the ovaries. Hey presto, we've got fertilization! As you can imagine this process is no cake walk for the female insect in question. It creates open wounds which often lead to infection, thus shortening life expectancy. There we have it folks, another post about kinky InSEX.
August 11, 2012
Lots of people in the L.A. area have been complaining about the heat. Over the last week, cities in our region have been experiencing temperatures well into the 90s. On Monday, Woodland Hills reached 108 degrees!Whenever the temperature rises like this, I start to notice ants indoors. Only this morning during our Nature Lab meeting, I found a trail of ants leading to the sink, and another leading to the snack shelf.The ants I found are Argentine Ants, Linepithema humile. They are an introduced species from South America (Argentina and Brazil) and are now considered the most common ant in our area. According to the Insects of the Los Angeles Basin book, these ants were "introduced to New Orleans before 1891 in coffee shipments from Brazil, and it has since spread rapidly over much of the United States."This is what the same book has to say about their pest status:"The species is one of the most persistent and troublesome of all our house-infesting ants. Argentine Ant workers seek out and feed on almost every type of food, although they are especially fond of sweets. Making themselves most objectionable, the ants invade the house through minute crevices and cracks—filing along baseboards, across sinks, and over walls and tables in endless trails."How do you feel about ants in your home? While writing this blog, I've found it interesting to ponder this question. As you may have noticed I am a nature lover, however I am definitely not a fan of ants in my house and will go to great lengths to remove them. Many times this feels like a losing battle, especially because I'm not one for spraying pesticides all over the place I live.
Argentine Ant about to take drink of water in our Nature Lab trailer(It is one eighth of an inch long)The Argies, as we "fondly" refer to them, have also been found throughout the North Campus. This isn't surprising as it is well documented that this ant species has displaced many of our native ants. According to Alex Wild, author of the Myrmecos ant blog, Argentine Ants, "can drive native arthropods to extinction, instigating changes that ripple through ecosystems. In California, horned lizard populations plummet. In South Africa, plant reproduction is disrupted. Worldwide, the Argentine Ant is a persistent house and crop pest. This is not a good ant." Here are some pictures of their activities on the North Campus:
Argentine Ants killed all the paper wasps in this nest
Argentine Ants tending citrus scales in our orange treesWhen I found the ants had killed all the paper wasps in the nest pictured above, I have to admit I was disappointed. I know many would be cheering for the ants, as paper wasps are viewed as a pest themselves. However, I had already become invested in the livelihood of that particular wasp nest and would check up on it every time I was out in the gardens. I find it infinitely interesting to ponder our notion of pest. What is acceptable in some circumstances is unacceptable in others. However, I still haven't come across anyone who is a fan of Argentine Ants!Need tips of managing ants in your home? Check out the UC Davis Integrated Pest Management website.
May 31, 2012
I've been spending a lot of time thinking about rats. Thankfully, it is not because I have a problem in my apartment! Unfortunately, for many people in L.A., rats are a serious pest, and it's not just one type of rat. The most serious rodent offenders in our cities are the brown (aka Norway) rat, Rattus norvegicus, and the black rat, Rattus rattus.
What species of rat is this? Here on the North Campus we have camera trap images and footage of rats hanging out underneath the bridge. But what type of rat is this? Since Jim Dines, our Mammalogy Collections Manager, wasn't available, I decided to try and figure it out myself. Doing a Wikipedia search for brown rats, I came across a nice diagram that helped me to make an identification. What species do you think it is?
Comparison of the physique of a black rat, Rattus rattus, with a brown rat, Rattus norvegicus, from wikipedia Using this diagram I looked closely at the ears and the eyes of the rat. Based on the relatively large size of the ears and the eyes, I determined the above image was of a black rat rather than a brown rat. I showed the image to Jim and he confirmed that it was indeed a black rat!
Black rat (top) and brown rat (bottom) from the Museum collection. Note the tail to body length ratio. Regardless of the species, why do people hate rats? As I referenced in the introductory paragraph, rats are sometimes pests in our homes, but what exactly do people think about rats? I did a Google search for, "why do people hate rats," and this is what I found. "Cute or not they're germ-ridden disease carrying vermin who in addition, can cause untold damage. THAT'S WHY." I also found this: "Rats are pests to humanity, but I personally believe that people especially hate rats because they subconsciously identify with them and see them as a reminder of themselves." Finally, someone else wrote: "A lot of rat-hatred goes back as far as plague. Rats were responsible for the disease that killed thousands of people." But, is plague a worry for us today in L.A.? Not really here in the city (I hear a collective YAY)! Firstly, according to the Centers for Disease Control and Prevention the last cases of urban, rat-associated plague occurred in L.A. in the 1920s. However, plague is present in L.A. County, and the principal mode of infection is from infected fleas living on wild rodents in rural areas. These rodents include California ground squirrels (remember the recent blog post?) and chipmunks! According to L.A. public health officials, "the major threat of plague to humans is in the rural, recreational and, wilderness areas of the Angeles National Forest, as well as the Santa Monica and San Gabriel Mountains." But, before you swear off recreating in our lovely parks forever, know that there have only been four cases of the plague in L.A. since 1979, none of which were fatal (another YAY for antibiotics and modern medicine). P.S., Plague is actually caused by a bacteria, Yersinia pestis, that lives in the blood and other bodily fluids of fleas, rodents, and other mammals.
March 16, 2012
We have another new sighting for the North Campus. A California ground squirrel has been spotted using the opossum den located underneath one of our Museum sheds. So far it seems that both the opossums and the squirrels are sharing the space!
Sam Easterson's camera trap captures the first image! This is what Jim Dines, our Mammalogy Collections Manager, has to say about them: The California ground squirrel, as its name suggests, is common throughout California as well as the rest of the western U.S. Scientists know this rodent as Otospermophilus beecheyi (formerly known as Spermophilus beecheyi). They are diurnal (active during the daylight) and, like other ground squirrels, live in burrows that they excavate or take over from other animals. Our ground squirrel has apparently moved into a den built by an opossum. Ground squirrels eat seeds, nuts, and a variety of other plant material, as well as insects and handouts left by humans. Since they also invade gardens and cultivated areas, California ground squirrels are commonly regarded as pests. Their extensive burrow systems can be very destructive. They are also a host to fleas that can carry plague, so pose a health risk to humans and their pets. Rattlesnakes are one of the main natural predators of California ground squirrels and the squirrels have developed an interesting defense mechanism: the ground squirrels will eat the shed skins of rattlesnakes and then lick themselves and their young, thus covering themselves with rattlesnake scent and confusing a potential rattlesnake predator into thinking it is merely smelling another rattlesnake. Pretty sneaky, eh? The California ground squirrel has a fairly bushy tail so is sometimes mistaken for the Eastern fox squirrel (a tree squirrel), but has different colored fur and retreats underground instead of up into a tree. Watch Sam accidentally startle the squirrel into the den!
January 5, 2012
Last Friday two Indian walking sticks, Carausius morosus, mysteriously showed up inside the Museum! They didn't escape from the Insect Zoo (we've never kept this species of walking stick before), and we haven't been able to find out exactly how they got here. What we do know is that the insects were discovered after a visitor felt one "fall" on his arm, and then promptly reported it to a staff person.
One of the Indian walking sticks found in the Museum!Indian walking sticks, a.k.a. laboratory walking sticks, are one of the most common walking sticks around. They are often kept as pets and classroom teaching tools, and their eggs can even be purchased on eBay for fish food! Surprisingly these insects have recently established themselves in our area through inadvertent or purposeful introductions. How does one inadvertently introduce stick insects into the environment?Indian walking sticks can reproduce parthenogenetically, that is without sexual reproduction. Therefore females can produce eggs regardless of the presence of males. The eggs are very small, about 3mm in length, and look a lot like tiny stones. Female sticks lay their eggs by dropping them directly to the ground, where they accumulate in the leaf litter. When they are in captivity, fecal material, partially chewed leaves, and eggs accumulate very quickly at the bottom of walking stick enclosures. To keep the insects clean and safe it is important for owners to clean this material out on a regular basis. For the untrained stick keeper, it is very easy to inadvertently discard eggs. Often this will be directly into the trash, or maybe even into the backyard compost pile. Paired with purposeful introductions, "I can't keep this pet anymore, I'm sure it will be better outside," is it any wonder that these insects have established themselves in numerous areas around Los Angeles?
Indian walking stick eggs (photo courtesy of Dr. Arakelian)According to Dr. Gevorak Arakelian, Senior Biologist in the L.A. County Department of Agricultural Commissioner, Indian walking sticks have recently been downgraded from a B rating to a C rating. This means that they aren't viewed as serious pests that need to be eradicated. However, for gardeners and the nursery industry these insects can still be troublesome. They eat a wide variety of landscape plants including rose, bramble, camelia, hibiscus, geranium, oak, and English ivy (the list goes on). Next time you find mysterious chew marks on your rose bush, take a closer look and see if you can find a walking stick hiding nearby.For more information check out Dr. Arakelian's Indian walking stick fact sheet.
December 16, 2011
Last week, while I was away in Costa Rica finding amazing bugs of all varieties, Sam's camera trap discovered a new species of mammal for our North Campus list!
Raccoon found under bridge in North CampusOpossums, squirrels, dogs, and cats have all been spotted in the North Campus since we planted the space, but until recently we had only suspected that raccoons were part of that mix too. Raccoons, Procyon lotor, are common urban mammals often found in the urban core. These nocturnal mammals are notorious for destroying new lawns as they try to reach the tasty grubs and other insects that come to the surface after heavy watering. They are clever little creatures and will neatly roll up the new turf to get to the tasty invertebrate morsels they are craving. Another pestiferous trait is their proclivity for dumpster diving. They can often be heard in the middle of the night knocking over trash cans and tearing into trash bags, looking for leftovers and other edible waste. Of course, the raccoons are not dumb; they want an easy meal! They'll bypass all the aforementioned nonsense if there's easily available free food—a.k.a. Fido's pet chow!
Raccoon stealing Amy's pet chow!About a month ago, I met Amy at the Green Festival at the Los Angeles Convention Center. I had a raccoon pelt with me which prompted her to tell me about the raccoons that vist her front yard every night in downtown Long Beach to eat her pet's food. One night Amy decided she would try and foil the raccoons and put the pet chow in a sealed rolling container. However, the raccoons weren't having their free dinner taken away. They actually figured out how to open the container (even rolling it down the stairs) and gorged on the hidden food!
Something's been searching for bugs!Luckily there's no pet chow to be had in the North Campus, but they're obviously finding plenty of food here. I'm pretty sure the raccoons are responsible for the many small divets I've seen in the mulch, as this is where the grubs and other insects are hiding. Mmmmmm tasty!