Molecular phylogeny of Pemphiginae (Hemiptera: Aphididae) inferred from nuclear gene EF-1alpha sequences.

Three traditional tribes of Fordini, Pemphigini and Eriosomatini comprise Pemphiginae, and there are two subtribes in Fordini and Pemphigini, respectively. Most of the species in this subfamily live heteroecious holocyclic lives with distinct primary host specificity. The three tribes of Pemphigini (except Prociphilina), Eriosomatini and Fordini use three families of plants, Salicaceae (Populus), Ulmaceae (Ulums) and Anacardiaceae (Pistacia and Rhus), as primary hosts, respectively, and form galls on them. Therefore, the Pemphigids are well known as gall makers, and their galls can be divided into true galls and pseudo-galls in type. We performed the first molecular phylogenetic study of Pemphiginae based on molecular data (EF-1alpha sequences). Results show that Pemphiginae is probably not a monophylum, but the monophyly of Fordini is supported robustly. The monophyly of Pemphigini is not supported, and two subtribes in it, Pemphigina and Prociphilina, are suggested to be raised to tribal level, equal with Fordini and Eriosomatini. The molecular phylogenetic analysis does not show definite relationships among the four tribes of Pemphiginae, as in the previous phylogenetic study based on morphology. It seems that the four tribes radiated at nearly the same time and then evolved independently. Based on this, we can speculate that galls originated independently four times in the four tribes, and there is no evidence to support that true galls are preceded by pseudo-galls, as in the case of thrips and willow sawflies.