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Project Lab 

October 16, 2013

There’s Bugs in My Paint, and I’m eating WHAT?!!

Cochineal

Before I became a biologist, I spent about 15 years as a licensed painting contractor. During the warmer months, a constant annoyance was the fact that insects were attracted to the bright colors and strong reflections of fresh paint, and my pristine white living room wall would be full of moths and gnats imbedded in the fresh paint, requiring me to carefully pick them out and touch up the paint, something that really ‘bugged’ me.  I no longer make my living this way, but last month I was helping a friend restore and paint a house that had smoke, water and mildew damage, and I remembered from my contracting days that the best way to solve these problems was to use a shellac-based primer. Then it dawned on me…shellac is a product made from insects! Shellac is produced from the secretions of the female lac bug, (actually a group of similar species of plant juice sucking true bugs). Depending on the host plant, it may be a pale yellow through a dark crimson color, and has been used historically as a dye and medicine.

Lac-1

India is the prime producer of lac, and the insect that produces most commercial lac is known as Kerria lacca, though there are several other species and countries that produce lac.  When it is refined, lac can be dissolved in ethyl alcohol to form shellac, which is used as a wood finish and sealer ingredient, as is also used in some nail polishes.

 

Paratrichardina decorella

 

IMG_0003-19

But wait, there’s more!  As Halloween and Thanksgiving approach, many of us will be looking forward to some of our favorite treats, such as ‘candy corn’ and other candy treats.  An examination of the ingredients in my candy corn showed confectioners glaze listed right after sugar and corn starch. Confectioners glaze is food grade shellac. I’m eating bug secretions!  Many other candies and other food products make use of shellac as an ingredient, coating, or polish (some citrus and apples). Many pharmaceuticals also use shellac as a pill coating.  These revelations got me to thinking about other insects that find their way into our food supply (other than the FDA allowable percentage of insect parts in peanut butter and grains).  I remembered that last year, Starbucks came under fire for using carmine coloring in one of its Frappuccinos®, because carmine is the product of the cochineal bug, a scale insect related to the lac bugs (Carmine, cochineal dye and natural red #4).  This scale insect inhabits Opuntia cactus in Mexico and South America, and produces carminic acid as a deterrent to predators. Though the thought of eating bug secretions might gross you out, these are natural products and are no doubt safer than the coal tar derived red food colorings used in its place. Carmine is also used as a red coloring in cosmetics like lipstick and make-up, and has also been used as a fabric dye.

As an entomologist, I have become aware that one way or another, we are never far from the presence of insects. These are just a few more examples of how insects are pervasive in human affairs.

Until next time,

Vic Smith

Curatorial assistant and imaging specialist


Filed under: Uncategorized — project_lab @ 3:34 pm

October 9, 2013

Attack of the jellyfish- a sign of imbalance in the ocean

The subject of surging jellyfish populations in the ocean came up in discussion this week at a social gathering at the Academy.  I admire the beauty and elegance of jellyfish, but their numbers are disrupting the balance of marine ecological systems. Rising sea temperatures, overfishing, decreases in shark and sea turtle populations, increases in low oxygen levels, and run- off from agricultural fertilizers are just some of the factors, which may be leading to their proliferation. Little historical data documenting their populations has made it difficult to be absolutely certain there are more, which is also leading to greater challenges to devise solutions to tackle the problem. Scientists from the University of British Columbia do have evidence showing 2,000 species of jellyfish have been appearing early than normal each year.

Photo 1

Their large numbers are becoming a nuisance since they are clogging pipes, which bring in water to nuclear power and desalinization plants. If cool water does not make it to the turbines of nuclear plants in a timely fashion it can lead to a devastating fall out, like that of Japan’s Fukushima Daiichi plant.

Increases in jellyfish may also be exacerbating ocean acidification (increases in the amount of carbon dioxide in the ocean lowers the pH, making it more acidic), since marine bacteria are less able to take in carbon from decaying jellyfish than they are from fish and other marine organisms. Rather than using this carbon to grow, the bacteria are breathing it out as carbon dioxide. Jellyfish are also disrupting marine food webs, since they are consuming larger amounts of plankton, depriving smaller fish of their food. Since fewer organisms feed on jellyfish, nutrients are also not being adequately transferred up the food chain.

Photo 2

 

The box jellyfish, the most toxic jellyfish in the world responsible for over 5,000 deaths since 1954, has turned up in some unlikely places due to increases in ocean temperatures and changes in currents. Some have migrated as far north as North Carolina from the Caribbean. These occurrences have raised concerns about safety along beaches up and down the Eastern coast of the US.

So, you might be thinking, but what can I do about it?   Just a few of the ways you can help with the jellyfish infestation in our ocean include: supporting sustainable fisheries including those that prevent excess by-catch of jellyfish predators, such as sea turtles, and purchasing organic foods, which do not contribute to excess fertilizer input into the ocean.

Stay tuned for my next post on the Fukushima Daiichi plant nuclear fall out and its impact on the ocean.

 

Carissa Shipman

Graduate Assistant in Public Programs

Department of Invertebrate Zoology and Geology


Filed under: Uncategorized — project_lab @ 11:00 am

October 2, 2013

Specimen of the Day: Song Sparrow (Melospiza melodia)

Today in the Project Lab, I prepared a study skin of a Song Sparrow (Melospiza melodia).  Although not as prominent as their other sparrow contemporaries, I often hear Song Sparrows speaking to each other in Golden Gate Park through series of “barks,” saying “here I am” and “where are you?”  These small birds can be identified by their streaked breast with central dark spot and heavy malar stripe.  As I walk to work, I start to wonder what interesting things can be learned from this bird.  What in our collections can help us understand more about Song Sparrows?

Slide2

 

The International Union for Conservation of Nature (IUCN) currently classifies the Song Sparrow as a species of “least concern.”  Species in this category are seen as stable populations that presently do not fit into the threatened or extinct category.  Although they are a species of “least concern,” it doesn’t mean they don’t face fierce competition from other birds.  Song Sparrows can be victim of brood parasitism, which is when one bird species lays their eggs in other bird species’ nests.  So how does this happen, and why?

Bird nests come in a wide spectrum of shapes, sizes and materials.  Some birds build completely enclosed nests and other birds lay their eggs directly onto the ground.  Song Sparrows are open cup nesters, meaning their nests look like a cup or a bowl.  Eggs are laid at the bottom of the “cup” and the parent provides warmth and cover by sitting inside the nest.  When these nests are left unattended, brood parasites can swoop in and place their own eggs into the exposed nest.

Insert photo of nests.

Slide1

Brown-headed Cowbirds (Molothrus ater) will lay their eggs in nests of Song Sparrows when the moment is right.  Both lay eggs that look very similar, which may be an adaptation that allows brood parasites to deceive the host.  For Song Sparrows, sometimes the egg is noticed right away and the parent will kick the Cowbird egg out of the nest, but other times the parent will unwittingly raise the Cowbird chick, occasionally to the detriment of its own young.  The Cowbird adult is effectively relieved of parental duties and can invest energy into foraging and breeding, rather than nest building and raising young.

Brood parasitism is seen in cuckoos, some ducks, and a few different passerines. There are many theories as to how this strategy has arisen over time.  The relationship between the brood parasite and its host can be complicated, constantly evolving with one trying to outwit the other.  Song Sparrows and Brown-headed Cowbirds are only one example of this fascinating phenomenon.  Eggs and nests here in the Academy’s collection can be used to study brood parasitism and how it evolves over time.  How much of a role does egg mimicry play?  How much of a role does nest shape play?  These are questions that can utilize the amazing egg and nest collection right here in our very own museum.

 

Codie Otte

Curatorial Assistant and Specimen Preparator

Ornithology & Mammalogy Department


Filed under: Uncategorized — project_lab @ 10:00 am

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