The Asphondylia auripila group (Diptera: Cecidomyiidae) consists of 15 closely related species of gall-inducing flies which inhabit creosote bush (Zygophyllaceae: Larrea tridentata). They have partitioned the plant ecologically with different gall midge species inhabiting the leaves, stems, buds, and flowers of creosote bush. Each species induces a uniquely shaped gall but the insects are otherwise morphologically very similar and very difficult to tell apart. Their life cycle begin