Five of the most important reference collections of world Thysanoptera are housed within research institutes in California.
The University of California at Riverside, Department of Entomology, houses a collection of approximately 450 named species, together with many flagged but unnamed species from California. Although this is one of the smallest collections, it is in many ways the most useful, because of the high quality of the slide mounted specimens together with details of host associations.
The University of California at Davis, Department of Entomology, houses a collection of nearly 800 species from many parts of the world and a total of over 25,000 slides.
The University of California at Berkeley, Department of Entomology, houses a collection that includes about 170 species.
The California Academy of Sciences, San Francisco, houses a particularly rich collection, with type material of 440 species from around the world.
The California Department of Food and Agriculture, Sacramento, houses an extensive collection that includes over 600 species.
Incorporated into the major holdings of the Smithsonian Institute, at USDA Beltsville, this collection preserves important Californian thrips material.
The Illinois Natural History Survey, Urbana, houses type material of a few Californian thrips.