Essential Inorganic Salts for Nymphal Growth of the Planthopper, Laodelphax striatellus FALLEN (Hemiptera: Delphacidae)

Abstract

Essential inorganic salts for the nymphal growth of Laodelphax striatellus FALLEN were examined by changing their composition, and the concentrations of MgCl₂⋅6H₂O and KH₂PO₄ in the MED-1 holidic diet. Mg, K and PO₄ were found to be essential. MgSO₄⋅7H₂O could be used as Mg source instead of MgCl₂⋅6H₂O. The KH₂PO₄ could be substituted with either K₂HPO₄ or K₃PO₄. When H₃PO₄ was present, KCl, KHCO₃, C₆H₅K₃O₇⋅H₂O and CH₃COOK showed about the same nutritive values. When KCl was present, H₃PO₄, NaHPO₄⋅2H₂O, Na₂HPO₄ and Na₃PO₄⋅12H₂O showed similar effects on the nymphal growth.