Saturday, March 28, 2020

Answer to Case 585

Answer to Parasite Case of the Week 585: Hard tick, Ixodes scapularis, unengorged adult female with intact mouth parts.

As several of you mentioned, it would be important to know the location for where this tick was obtained. This particular tick was obtained in Florida, although similar-appearing ticks are found on the west coast of the United States (Ixodes pacificus) and Europe (Ixodes ricinus). All three of these ticks serve as the vector for members of the Borrelia burgdorferi sensu lato species complex that cause human Lyme disease (Lyme borreliosis).

There are a couple of features below which can get you to the genus level pretty quickly: specifically, the inverted "U-shaped" anal groove and the lack of festoon. The following image shows these, and some other morphologic features.

You will then want to refer to specific keys for the morphologic identification of Ixodes ticks in the different regions of this world.

Thanks again to Florida Fan for donating this case!

2 comments:

Old One said...

Dr. Pritt

Could you possibly point out the porose areas. These are 2 patches on the dorsal surface of the basis capitulum near the base of the palps. They are the glandular openings where newly laid eggs are coated with a protective covering. Therefore they are found only on ADULT FEMALE TICKS.

Wonderful photos F.F.

ParasiteGal said...

Thanks for the suggestion Old One! I've now updated the image, and also included a few other key morphologic features.
Bobbi