Update: The book arrived some time ago, and I've read bits and pieces of it.rjlittlefield wrote: ↑Sun Aug 15, 2021 12:55 pmI have a book on order: https://www.amazon.com/gp/product/041256520X "Scuttle Flies: The Phoridae" by H. Disney, 1994. Current list price $299 but out of stock. Amazon found me a copy in the UK for less than $30 including shipping. (No, they aren't offering any more for that price.) I'll report back after the book arrives and I've had a chance to do some reading.
The book is dense and highly technical, 467 pages in total, with 178 pages just in Chapter 8 "Identification". Most of that goes only to genus level.
Speaking of "genus level", the book's index lists 236 species of Megaselia. But that was in 1994. At this moment in 2021, the Phorid Catalog at https://www.phorid.net/pcat/ lists 1690 species of Megaselia worldwide, with about 235 of those labeled as USA, N America, or cosmopolitan.
I was interested to see that the home page at https://phorid.net includes a navigation link, "How to recognize Megaselia scalaris, the most commonly seen phorid". The link goes to a file named "scalaris.php", which unfortunately is not present on the website or captured in the Internet Archive's Wayback Machine. I've sent some email to try tracking that down.
--Rik