In April 1982, at Urânia, State of São Paulo, Brazil, a high infestation of larvae of Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae) damaging roots, gynophores and pods of an irrigated peanut crop was observed. The roots, radicles and gynophores showed lesions due to the attack of the larvae; sometimes these plant parts were completely destroyed. The pods presented holes through which the larvae penetrated in order to eat the seeds. Because of the high infestation and the heavy damage the harvest of the crop was considered not economical.