Curious about the use of "chigger" . . . My field guide (Nat'l Wildlife Federation's Field Guide to Insects and Spiders of N. America) includes an entry for "Chigger (Trombicula alfreddugesi)" with a photo of an eight-legged adult mite (implying that the name "chigger" refers to both the larva and the adult). The Wikipedia entry for Trombiculidae / Chigger states that "chigger" is applicable to members of Trombiculidae whose larvae bite, implying that the name applies to the species, not the life cycle stage. Are these two sources examples of an imprecise use of a colloquial name?

Also, why is the BugGuide's Trombiculidae page so sparse? Shouldn't there at least be an entry for E. (or T.) alfreddugesi?

Hi Mark,

Welcome to the sometimes frustrating world of mite biology! :) A world where most of the information available is either completely incorrect, or misleading because the information isn't known by anyone. I am in the process of writing a misconception-focused article about chiggers and their relatives. I'll let you know when it's finished. Until then, here are some answers to your specific questions...

Nearly all of the images depicting chiggers are misidentified. The photograph in Nat'l Wildlife Federation's Field Guide to Insects and Spiders of N. America actually depicts a whirligig mite (Anystidae: Anystis) and much of the information found in that paragraph is incorrect with respect to both chiggers and whirligig mites. Ironically, the previous page (p. 413) depicts a line drawing of an adult chigger... even though the morphological terms therein are misleading. The Wikipedia article you mentioned depicts a certain velvet mite (Trombidiidae: Trombidium), not a chigger. There are very few accurate chigger images available, but here are three:

http://www.fcps.edu/islandcreekes/ecology/Arthropods/Chigger/chigger_adult_l.jpg
https://www.flickr.com/photos/artour_a/13210918005/
https://www.flickr.com/photos/artour_a/13345706854/

Interestingly, the first one comes from a webpage where most of the other images are incorrectly identified. This problem is also true of most paper references. For example, Baccaloni's Arachnids depicts a concrete mite (Balaustium), not a chigger.

The Bugguide trombiculid page is so sparse because no one is photographing chiggers. I'll eventually add some of my photos when I can. The E. alfreddugesi page is blank because chiggers are diverse and nearly impossible to identify without examining properly slide-mounted specimens. So far, no one has posted photos of this species.

The common name "chigger" derives from the stage that bite humans... and it is the larvae that do this. But I absoultely refer to the whole family (Trombiculidae) as "chiggers", and I encourage you to do the same. In other words, like with most common names, it applies to whatever you want it to contextually :)

Thanks for the questions!