Family Hypochthonellidae China & Fennah, 1952
The Hypochthonellidae consists of a single species, Hypochthonella caeca China & Fennah, 1952, found in southern Africa (Zimbabwe). It is the only known true endogean fulgoroid taxon (i.e., interstitial soil organism) (Hoch 2002) and apparently the only higher planthopper with subterranean habits as an adult. The other planthoppers with subterranean habits are more basal groups – viz. Cixiidae, Kinnaridae, Meenoplidae and one Delphacidae). Hypochthonella caeca was originally reported to occur “in great numbers” on the roots of “groundnut” (possibly Macrotyloma geocarpum, Vigna subterranean, or Arachis hypogaea (peanuts)), maize, and tobacco near Hartley, Southern Rhodesia (now Chegutu, Zimbabwe) (China and Fennah 1952). Although it was found “in great numbers” (along with attending ants) and was “associated with a decline in the plants” (China and Fennah 1952: 198), the species has evidently not been reported in collections since. The adults are pale and pubescent; their ocelli are absent and the eyes are reduced, their wings are reduced to pads extending only slightly onto the abdomen, their metathorax has a strigil‐like organ, and their abdomen has lateral wax glands on the sixth, seventh, and eighth segments. They appear generally similar to flatid nymphs except that they possess the strigil‐like organ and have a different arrangement of wax glands. The Hypochthonellidae have not been included in molecular studies of planthopper phylogeny. The phylogenetic affinities of Hypochthonellidae are unknown but are speculated to be near the Flatidae.
Family Hypochthonellidae China and Fennah 1952
1 species; nomative subfamily (Hypochthonellinae) and tribe (Hypochthonellini) only, erected by China and Fennah (1952) implication through the principle of coordination (ICZN 1999).
Hypochthonella China & Fennah, 1952
Hypochthonella caeca China & Fennah, 1952
Hypochthonella caeca, Hypochthonellidae (paratype; photo by Mick Webb, The Natural History Museum)
Hypochthonella caeca from China & Fennah, 1952 (my copy of this work is poor, I will provide a better scan, someday, when I have a better copy)
Distribution of the Hypochthonellidae from FLOW (2 Mar. 2018)
References
China, W. E. and R. G. Fennah. 1952. A remarkable new genus and species of Fulgoroidea (Homoptera) representing a new Family. Annals and Magazine of Natural History, Series 12(5): 189-199.
Hoch, H. 2002. Hidden from the light of day: planthoppers in subterranean habitats (Hemiptera: Auchenorrhyncha: Fulgoromorpha). Denisia 4: 139-146.
Hoch, H., M. Asche, C. J. Burwell, G. M. Monteith and A. Wessel. 2006. Morphological alteration in response to endogeic habitat and ant association in two new planthopper species from New Caledonia (Hemiptera: Auchenorrhyncha: Fulgoromorpha: Delphacidae). Journal of Natural History. 40. 1867-1886. 10.1080/00222930601046576.
ICZN. 1999. International Code of Zoological Nomenclature. Fourth edition. The International Trust for Zoological Nomenclature, London, UK. BHL. The Code Online (ICZN).
Metcalf, Z. P. 1957. General Catalogue of the Homoptera. Fascicle IV, Fulgoroidea, Part 13, Flatidae and Hypochthonellidae. North Carolina State College, Raleigh, North Carolina.
