Volume 9 of Fauna Entomologica Scandinavica is the first of four planned volumes dealing with the superfamily Aphidoidea of the infraorder Aphidodea (= Aphidoidea of Borner) within the order Homoptera, suborder Sternorrhyncha.
The volume comprises the introductory chapters to the superfamily and the systematic treatment of the families Mindaridae, Hormaphididae, Thelaxidae, Anoeciidae, and Pemphigidae. The next volume on Aphidoidea deals with the Drepanosiphidae (including the subfamilies Drepanosiphinae, Phyllaphidinae, and Chaitophorinae). The third volume deals with part of the Aphididae, viz. Pterocommatinae and Aphidinae: Aphidini. The fourth volume may appear in two parts, dealing with the remaining species, viz. Aphidinae: Macrosiphini and Lachnidae.
A zoogeographical catalogue is given in each of the four volumes, references are given in each volume, but those listed in the first, second, and third volumes do not reappear in the second, third, and fourth volumes, respectively. The last volume contains a host plant index of all species treated in the four volumes. Each volume has its own index of entomological names. The last volume is concluded with an index listing all entomological names in the four volumes. The Scandinavian species are provided with numbers continuing throughout the four volumes, but each volume is paged separately.