Gustaaf Hulstaert (1900–1990) was a Belgian entomologist mainly interested in Lepidoptera.
From 1925 Gustaaf Hulstaert was a missionary in the Belgian Congo. Before that year he had studied insects from the Dutch Indies (including Dutch New Guinea) sent to him by other missionaries. His collection is held by Naturalis Biodiversity Center in Leiden.
Hulstaert, G. 1923. On Lepidoptera from New Guinea, Kei, Tenimber, the Philippines, and Australia. Annals and Magazine of Natural History (9)11: 178–190.
Hulstaert, G., 1924 New Indo-Australian Noctuidae. Annals and Magazine of Natural History (9)13: 97–127.
Hulstaert, G., 1924 New moths from New Guinea, Kei, and Tenimber. Annals and Magazine of Natural History (9)13: 127–139.
Hulstaert, G., 1924 Heteroceres indoaustraliens nouveaux. Annales de la Société Entomologique de Belgique 64: 85–101.
Hulstaert, R.P.G. 1924 Pieridae nouveaux de l'Afrique Central. Revue de Zoologie et de Botanique Africaine 12:90–99.
Hulstaert, R.P.G. 1924 Lycaenidae nouveaux des collections du Musee du Congo Belge. Revue de Zoologie et de Botanique Africaine 12:112–122; 173–194.
Hulstaert, R.P.G. 1924 Rhopaloceres nouveaux du Congo Belge. Revue de Zoologie et de Botanique Africaine 12:476–481.
Hulstaert, R.P.G. 1926 Rhopaloceres nouveaux du Musee du Congo Belge. Revue de Zoologie et de Botanique Africaine 14:60–63.
Hulstaert, R.P.G. Lepidoptera Rhopalocera, Fam. Danaidae, Subfam. Danaidinae and Tellervinae. Genera Insectorum (1931)[ii] +
