Influence of soil moisture on root feeding and growth rate of Sericesthis nigrolineata larvae (Scarabaeidae : Coleoptera)

Growth and feeding by third-instar larvae of Sericesthis nigrolineata (Scarabaeidae: Coleoptera) were compared in wet soil and dry soil in the presence and absence of perennial ryegrass plants under laboratory conditions. Larval feeding rate was similar in wet and dry soil in the presence of plants and in wet soil in their absence, but was reduced in dry soil when roots were not available. Larvae gained weight over 42 days in both wet and dry soils in the presence of plants and maintained their initial weight in wet soil and lost weight in dry soil in the absence of plants.