Ontogenetic and static allometry of hind femur length in the cricket Gryllus bimaculatus (Orthoptera: Gryllidae) with implications for evo-devo of morphological scaling

Abstract

The evolution of morphological allometry or scaling is a long-standing enigma in biology. Three types of allometric relationships have been defined: static, ontogenetic and evolutionary allometry. However, the theory of the interrelationship between these three types of allometry have not been tested in Orthopterans and to a lesser extent in hemimetabolous insects. Here, the ontogenetic allometry of hind femur length in the cricket Gryllus bimaculatus was observed to be slightly positive as compared with a negative allometric relationship for Orthopterans in general, while the instar-specific static allometries were highly variable. The findings give support for the size-grain hypothesis in Orthoptera and indicate that ontogenetic allometries may not predict evolutionary allometries. The current model for the developmental basis of allometry derived from holometabolous insects is extended into a phylogenetic context and the potential of G. bimaculatus and other Orthopterans for further experiments of evo-devo of morphological scaling is discussed.