Large Tree:
Gumbo Limbo (Bursera simaruba), with its smooth, reddish, peeling bark, grows in the hardwood forests of South Florida. Flycatchers and other birds feed heavily on its small fruits. Eastern, Western and Gray Kingbirds, along with Great Crested and Scissor-tailed Flycatchers visit during March and early April
Live oak (Quercus virginiana), a stately native of southeastern United States, is a favorite of woodpeckers, especially the Yellow-bellied Sapsucker, as well as many other insect-eating birds. Ruby-throated Hummingbirds feed on the pollen. The leaves are the larval food of the gorgeous, iridescent blue white-M hairstreak, a fast-flying native butterfly, while the acorns are eaten by gray squirrels, blue-jays and woodpeckers.
Medium Trees:
Coffee colubrina (Colubrina arborescens) produces clusters of tiny greenish flowers which give off a sweet odor detectable from great distances, attracting an abundance of insects, mainly nectar-seeking bees and wasps. Flycatchers, gnatcatchers and warblers abound during its extensive flowering season, taking advantage of the cornucopia of insects drawn to the flowers.
These are the main attractors, but if you build a small, dense area of bushes you will find that birds will come and make homes there, which can only help.
On Buzzard's Roost, we have clearings surrounded by forest, this helps us with keeping the beneficial animals around quite a bit. This year we had a two month period (April and May) where we had no wasps, now that the heat is here they are coming back, unfortunately the flycatchers appear to have moved on, but we are now starting to see other wasp eating birds begin to show up. I know the problem your having and if I come up with a real solution I will post it for everyone.