Theron, J.G. 1968 Studies on the morphology and relationships of male Apiomorpha and Opisthoscelis (Hemiptera: Coccoidea).. Australian Journal of Zoology. Melbourne 16: 87-99.

Notes: Both genera belong to lecanoid group of Coccoidea, but their relationship to various families of lecanoid group is uncertain; they show some affinity with Eriococcidae.