Asked April 15, 2021, 1:21 AM EDT
Douglas County Oregon
Here is an Extension article that helps to address the True Flies category https://extension.oregonstate.edu/pests-weeds-diseases/insects/true-flies-order-diptera
True Flies are those in the order of Diptera. Although many insects are termed "flies," only those having one pair of wings belong to the insect Order Diptera.
The "True Flies" are those with wings in the insect Order of Diptera. https://www.si.edu/spotlight/buginfo/true-flies-diptera