Cerataphis jamuritsu, a Subtropical Aphid Producing Soldiers in Large, Hard Galls (Homoptera)

Of five cerataphidines that form galls on Styrax suberifolia in Taiwan, "Astegopteryx" jamuritsu is the only species whose life cycle and taxonomic position remain unclear. We found three mature galls of the species in southeastern Taiwan. The galls were very hard and of single-cavity type. Examination of the morphology of 1st-instar nymphs deposited by alates revealed that the life cycle is host-alternating, and that the species belongs to the genus Cerataphis. The aphids were found to harbor slender yeast-like symbionts, like other genuine Cerataphis species. It has been hypothesized that the species produces soldiers that readily fall off their gall when disturbed. We found numerous 2nd-instar soldiers in the galls, but they did not readily fall off the galls. Keys to the five species based on the 2nd-instar soldier and the mature gall are given.