What do Eumerus Meigen larvae feed on? New immature stages of three species (Diptera: Syrphidae) breeding in different plants

The genus Eumerus Meigen 1822 (Diptera: Syrphidae) is widely distributed in the Old World, though recently introduced into America, and their larvae feed on decaying vegetal material and/or inside underground storage organs of many plants, sometimes generating economic losses as pests. However, little is known about Eumerus larval cycles and their interactions with host plants. Here, immatures of three Eumerus species from different continents...