Differentiation and increase in size of nymphal instars of Monistria discrepans (Walker) (Orthoptera: Pyrgomorphidae)

Abstract

The width of the pronotum, length of the metathoracic tibia and femur, total length, and number of antennal segments were determined in the laboratory in Queensland for nymphs in all the instars and adults of the grasshopper Monistria discrepans (Wlk.), a potential biological control agent for the weed green turkey bush (Eremophila gilesii). Total body length was the most useful measurement for the identification of nymphs in the various instars. Growth of the pronotum, metathoracic tibia and femur, and body length all conformed to Dyar's rule and Przibrum's principle.