Morphology,development and reproduction of Zonocerus variegatus (L.) (Pyrgomorphidae) feeding on Vernonia amygdalina (Asteraceae) and Manihot esculenta (Euphorbiaceae) in the laboratory

Vernonia amygdalina (asteraceae) and manihot esculenta (euphorbiaceae) are food sources for human and hosts plant of the african pest zonocerus variegatus (l.) (orthoptera : pyrgomorphidae). in this study,survival,larval development,morphology and reproduction of z. variegatus on m. esculenta and v. amygdalina were investigated in the laboratory. the experiments were conducted in 180 cages and in each,a couple of stage 4,5 or 6 larvae were introduced. larvae and adults were nourished with leaves of m. esculenta or v. amygdalina. the experiments were monitored every two days,from november 2010 to september 2011,until the death of all the individuals. the results revealed that z. variegatus survivorship was more than 83% and was not affected by diet change. the development proceeded normally and no supernumerary larval stage was noticed. adult lifespan and the number of ootheca per female were higher on m. esculenta than on v. amygdalina. when the breeding started with the stage 4 and 5 larvae,the dimensions of the eggs were not affected by the diet variation; but when breeding started with stage 6 larvae,eggs were larger on v. amygdalina than on m. esculenta. the diet variation did not affect the body dimensions of z. variegatus,except for the abdomen of adults derived from the larvae which were monitored since stages 5 or 6. the sexual dimorphism was noticed on the two diets. this work has provided an important data on the advancement of ecological knowledge on z. variegatus. copyright 2014 zoological society of pakistan.