Mark Fink

http://www.hhpz.org/files/hhpz/documents/AnimalFactSheets/Cattle%20Egret.pdf

I am no expert.  I just remember Geoff Lawton's permaculture design course where he said if you have insect problems then you need birds. What immediately comes to mind since I live in the sub-tropics are cattle egrets. They ride the backs of cattle. They eat anything that moves. I have told mine that they are welcome anytime, telepathically of course! And they seem to understand that and believe it or not they seem to have developed some bond with me and keep coming back or so I think. Soldier flies will keep black flies from breeding and manure piles down. http://aggie-horticulture.tamu.edu/galveston/beneficials/beneficial-51_black_soldier_fly.htm  Bats will devour mosquitoes and other insects. If it were me I would make a home for all of these diverse possibilities rather than rely on labor intensive herbal or poisonous concoctions - if possible. I found this on bot fly predators, it seems a parasitic wasp lays its eggs on bot fly larvae, but can be killed off by insecticides.  http://www.bendsource.com/bend/what-goes-round-come-around-the-curious-life-of-bot-flies/Content?oid=2132188

I have experience with grow beds on concrete if it helps any. I live in south Florida where soil pH is 8.5 - so I grow all of my vegies in raised wicking beds (concrete blocks stacked 3 levels high) on my back patio made of concrete. The first level is a plastic sheet with granite gravel filled one block high. It has a perforated 4 inch plastic flexible drain pipe that esses through it 3 times the length. On top of that first level is a plastic ground cloth. On top of that 2 blocks high is composted soil. Rain water from the roof can fill the wicking bed via the perforated pipe. I have had great results with this system. Zero complaints.