During the summers of 2011 through 2013, we used trap-nests to survey assemblages of solitary cavity-nesting Hymenoptera and their nest associates, at two sites within Finger Lakes National Forest in central New York State. The 525 occupied trap-nests produced>2,000 identifiable offspring. Nest-provisioners included 13 species of wasps (Sphecidae, Crabronidae, Vespidae, Pompilidae), of which the most common were Isodontia mexicana, Trypoxylon lactitarse, and Ancistrocerus antilope. Of the 14 species of nest-provisioning bees (Megachilidae, Colletidae), the most frequent nest occupants were Megachile campanulae, Hylaeus annulatus, Osmia pumila, and Osmia cornifrons. The most prevalent natural enemies of nesting species were Coelioxys modesta (in M. campanulae nests), sarcophagid flies (in nests of several wasp species), and Leucospis affinis (in megachilid bee nests). The study documents the presence of 10 species not found associated with trap-nests in our previous two surveys in the Finger Lakes region: Isodontia auripes, Euodynerus leucomelas, Trypoxylon tridentatum, Osmia caerulescens, O. cornifrons, Hylaeus modestus, Megachile sculpturalis, Omalus aeneus, Sapyga centrata, and Coelioxys modesta. We review the results of the trap-nesting studies we have conducted in the region since 2001, providing a compilation of data on patterns of nest-size use for the most common species. Overall, our trap-nest studies have now recorded 38 species of nest-provisioning wasps and bees, along with 14 species of brood-parasitic Chrysididae, Megachilidae, and Sapygidae.