The Morphology and Relationships of the Stenocephalidae and Hyocephalidae (Hemiptera: Heteroptera: Coreoidea)

Abstract

The cuticular anatomy of the Stenocephalidae and Hyocephalidae confirms that they 1) are closely related each to the other, 2) are primitive within the Coreoidea, and yet 3) possess some apomorphies. Autapomorphies of the Hyocephalidae include a filament of the metathoracic scent-gland channel, the presence of a 3rd-sternal “strainer,” the arrangement of 5th-sternal trichobothria, and the lack of a vesica and sperm reservoir. Autapomorphies of the Stenocephalidae include the structure of the genital capsule's median projection, and an anterior projection of the male's 8th segment. Synapomorphies of the 2 families include the suturing between the 3rd and 4th abdominal sterna and other features of this region, a connection between the genital capsule's rims and the cuplike sclerite, the dorsal opening of the capsule, and asymmetries of the flange(s) of the spermathecal duct. Confirmation that other shared features are indeed synapomorphies must await study of other primitive Coreoidea.