Cerataphis vandermeermohri (Homoptera), a Tropical Aphid with Soldiers Falling off Their Huge Gall

Ramified galls of "Astegopteryx" vandermeermohri (Aphididae, Hormaphidinae, Cerataphidini) were collected from Styrax serrulata in Sumatra to investigate the life cycle and social behavior of the aphids, and the gall structure. The galls were of single-cavity type. It was found that the species produces 2nd-instar sterile soldiers which sting human skin and cause troublesome irritation. The colony size of one gall was estimated to be 94, 000, of which 45.6% were soldiers. Soldiers readily fell off this gall, but not from other two galls containing fewer aphids. The species was transferred to the genus Cerataphis based on the morphology of lst-instar nymphs deposited by alates.