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Bees of the Genus Megachile from the Belgian Congo

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Parasitic Bees of the Genus Coelioxys from the Belgian Congo

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Bees of the Genus Crocisa from the Belgian Congo and Notes on Trigona

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Bees of the Genus Sphecodes from the Belgian Congo

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Heriadine Bees from the Belgian Congo

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African Bees of the Family Megachilidae (Gronoceras and Megachilidae) from Liberia and Belgian Congo

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Heriadine and Related Bees from Liberia and the Belgian Congo (Hymenoptera, Apoidea)

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African Bees of the Family Anthophoridae, Cheifly from the Belgian Congo and Liberia (Hymenoptera, Apoidea)

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African Bees of the Family Ctenoplectridae from the Belgian Congo and Liberia (Hymenoptera Apoidea)

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African bees of the Family Xylocopidae Principally from Liberia and the Belgian Congo