Itchy-Scratchy!


Just in time for Halloween!  Yesterday I was using the Scanning Electron Microscope (SEM) at Friday Harbor Marine Labs.  I got to take some really cool photos but in order to use the SEM, your specimen has to be dried out.  Well, I had some specimens that are really tiny and very delicate and they weren’t dried out because it is a complicated process that takes a certain chemical called Hexamethyldisilazane (HMDS).  Also, drying out your specimen for viewing under the SEM renders it useless for viewing under a light microscope and you’ve lost the ability to preserve it in a collection.

So I’m going to share how I took images of some of my specimens at home with a pretty old compound microscope, an iPhone, and a clip-on macro lens from Amazon.   First, I’ll tell you a bit about the compound microscope image posted here.  This specimen is in the genus Damalinia, most likely the exotic chewing louse, Damalinia (Cervicola).

IMG_7536

Chewing louse Damalinia spp

It lives on black-tailed deer (Odocoileus hemionus columbianus) in Washington, Oregon and California, and has been indicated in what is called HLS (Hair-loss syndrome).  They build up in large numbers on deer at certain times of the year.  One factor thought to contribute to this is lack of adequate nutrition in the deers’ diet, particularly an absence or deficiency of Selenium.

In a nutshell, these lice can reproduce at high numbers in vulnerable deer (typically old, young, and those with weakened immune systems due to nutritional deficiencies or internal parasites).  The lice cause extreme itching, irritation, and hair loss.  The deer respond to the itchiness by excessive licking and grooming.   Why hair loss? Well, these lice are called “chewing lice” because they munch on hair, skin fragments and secretions, and in some cases will feed on blood from skin wounded from scratching.  It’s a miserable condition to have.  This is what a deer looks like that is suffering from HLS caused by the chewing lice.

hairloss

Photo by Brian Murray  https://www.dfw.state.or.us/wildlife/health_program/hairloss/index.asp

Here is a larger version of my photo.  It’s not as clear as I’d like, but I’m certainly going to practice to improve. Happy Halloween and I hope you don’t spend the night scrrraatching in bed!

IMG_7537

Chewing louse Damalinia spp.

Further reading and references:

Protocol for drying insects with HDMS: https://www.cdfa.ca.gov/plant/ppd/entomology/HMDS.html

Link to Amazon clip on iPhone lens set ~

Robinson, J. (2007). Transmission of the chewing louse, Damalinia (Cervicola) sp., from Columbian black-tailed deer (Odocoileus hemionus columbianus) to Rocky Mountain mule deer (Odocoileus hemionus hemionus) and its role in deer hair-loss syndrome. Masters Thesis. Oregon State University. https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/1v53k0068?locale=en

Roug, A., Swift, P., Puschner, B., Gerstenberg, G., Mertins, JW, Johnson, CK, et al. (2016). Exotic pediculosis and hair-loss syndrome in deer (Odocoileus hemionus) populations in California. Journal of Veterinary Diagnostic Investigation, 28(4), 399-407. http://journals.sagepub.com/doi/10.1177/1040638716647154

Maude, R. J., Koh, G. C., & Silamut, K. (2008). Taking photographs with a microscope. The American journal of tropical medicine and hygiene, 79(3), 471-2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2843439/

Smartphone Microscopy by Annie Morrison.  Youtube.

 

 

 

 

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s