A Movable Fleas’t

The specimens you are transcribing in this expedition are a portion of the Milwaukee Public Museum’s slide collection. They were all collected by Dr. Omar Amin, a professor at University of Wisconsin – Parkside, and, along with other slides, form the basis of his work on the internal and external parasites of animals in the region. 

You will notice there’s a fair amount of repetition in the collection – a very limited pool of hosts and parasites, and perhaps wonder: why so many? A dog flea is a dog flea, after all. But there’s a lot more to unlock in these slides. First, there’s host specificity. Fleas have some host fidelity (they’re called dog fleas for a reason, after all), but collections like this can give us quantifiable information about how often those fleas pop up on other hosts. In this collection, you’ll notice several instances of squirrel fleas (Orchopeas howardi) collected from the opossum (Didelphis virginiana). Collections like this one, taken in conjunction with collections of squirrel fleas from all over the country, can help scientists work out how common it is to find squirrel fleas on opossums, or if these fleas are just freaks. We can glean additional data, too–like if there’s a seasonality to flea abundance (e.g., infestations are more common at certain times of year), if male vs. female hosts are more likely to have parasites, and what the ratio of male to female parasite is on a given species during a given year.

Having a collection of parasite slides is essential to documenting the natural world both of today and of the past.  Your digitization efforts on these slides, or any other community science transcription project, helps unlock this material for scientists, veterinarians, and public health officials.

Visit the Terrestrial Parasite Tracker (TPT) project today to give this expedition a try.

— Julia Colby

Vertebrate & Invertebrate Collections Manager, Milwaukee Public Museum