Eriophyoids have a significant economic impact as weed pests, particularly when it comes to the malformations they can occasionally cause, such as rusting, bronzing, leaf rolling, erineum, bud galls, stunting, blisters, leaf galls, damaged seeds, and mosaic virus disease. Six eriophyoid mite species collected from Egyptian weeds are described. Aceria newplucheae sp. nov. is described as a vagrant on the leaf axil of Pluchea dioscoridis (L.) DC. (Compositae). A complementary description to the first-recorded species, Aceria chenopodia Xue, Sadeghi & Hong infesting Chenopodium album L. and Chenopodium murale L. (Amaranthaceae) in Egypt was done based on females, males and immature stages. Three eriophyoid mite species have been synonymized: Aceria noxia Flechtmann & Tassi is a junior synonym of Aceria lividus Elhalawany; Aceria mosalahi Lewandowski & Elsayed is a junior synonym of Aceria dioscoridis (Soliman & Abou-Awad); and Aceria aegyptiacus (Soliman & Abou-Awad) is a junior synonym of Aceria tosichella Keifer. Furthermore, Vittacus plucheae Abou-Awad & Nasr, a vagrant causing rusting on P. dioscoridis, is designated as a junior synonym of Neooxycenus plucheae Abou-Awad and re-described herein.