Maybe Brachymeria podagrica? These wasps were parasitoids of fly larvae that I found leaving the corpse of an opossum. See https://www.inaturalist.org/observations/59172466 for the larval host and https://www.inaturalist.org/observations/66813738 for the parasitized pupae.

Pupae formed by larvae found exiting the corpse of an opossum. See https://www.inaturalist.org/observations/59172466 for the larvae.

The fuzz here may have no relationship to the pupae, as I dumped the larvae into a container with a damp paper towel, the fibers of which may have gotten snagged on the surface of the puparia.

All sorts of mines, feeding sign, and leaf-tying on Populus fremontii. A single species at different development stages, or more than one species? Some leaves from this tree yielded the larva found at https://www.inaturalist.org/observations/66674668

I attempted to rear these leafmining flies, but the larvae went down the stems and drowned in the water I was using to keep the leaves alive (despite the fact I had covered all but the stem hole). The large yellow patches on the leaves are from becoming waterlogged. Host plant: Capsicum annuum (see https://www.inaturalist.org/observations/33820752 )

See also https://www.inaturalist.org/observations/66659340 for better photos of mines from this species.

A single species? Host plant: Capsicum annuum (see https://www.inaturalist.org/observations/33820752 ). These mines greatly increased in number the next year.

See also https://www.inaturalist.org/observations/66659342 for the larvae of this species.