Usually I don’t try to rear insects that I have previously, eventually, reared successfully. But in this case I’m glad I did.
August 12, 2014: collected
Anemone cylindrica with tell-tale sign of
Phytomyza anemonivora 
August 19, 2014: transferred from a jar to a baggie
November 19, 2014: transferred to another baggie but accidentally squished 1 puparium, darn me! Larva looked to be still viable but was it a fly or a wasp inside the puparium? (Didn't take a photo.)
September 13, 2015: pulled apart the Anemone seed heads (retain the seeds!) to find puparia
December 25, 2015: finally took the time to look more closely, just before discarding. Emptied the baggie to find: 2 adult (dead) flies, spent puparia and what looked to be a gall wasp

but that couldn't be. Was there an undetected gall in the container? Did I contaminate this rearing? Do I not know what gall wasps look like? What was this all about? So I started pulling apart the seed heads and there, inside, is another gall wasp type

as well as 3 adult flies that died while emerging

, and more dead puparia. Pulling more seeds apart there was another spent puparium with a wasp between the puparium and the popped off cap

. What's going on? Well, if all else fails I pull out Borror and Delong
Study of insects and discover a family (and subfamily) of insects new to me. What fun!
Batch rearing