During routine phytosanitary inspections performed in February 2021 on vegetable crops in the region of Sidi Bouzid, Central Tunisia, unusual severe and generalized damage on young garlic, Allium sativum L., crops were observed. The causal agent was later identified as the seedcorn maggot Delia platura Meigen (1826) (Diptera: Anthomyiidae) using morphological and DNA-based approaches. Symptoms on garlic are described and brief notes on diagnostic features of both adult and juvenile instars are presented. Possible phytosanitary risks and control measures are discussed.