LAUSR

Descriptions of the immature stages of the planthopper Lepidelphax pistiae Remes Lenicov (Fulgoromorpha), a specialist herbivore of Pistia stratiotes L. (Alismatales) from Argentina, are provided for the first time. P. stratiotes, or water lettuce, is an important weed in fresh water bodies of the tropics and subtropics. Newly emerged nymphs from eggs collected in the field were reared in rearing chambers. Fifth nymphal instars may be easily recognised by the whitish colour with a distinctive blackish antennal flagellum and ungues, and the relatively long frons and rostrum. Information is provided on nymphal behaviour and the main features of the fifth nymph instar that distinguish it from the two other delphacids that live and feed on plants from central and northern Argentine wetlands.