Comparative isoenzyme electrophoreses between the brown-spotted locust, Cyrtacanthacris tatarica , and the desert locust, Schistocerca gregaria

The desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), and the brown-spotted locust, Cyrtacanthacris tatarica (Linné) (Orthoptera: Acrididae), were collected from Saudi Arabia to investigate their relationships . Native polyacrylamide gel electrophoreses of five arbitrarily chosen metabolic enzymes extracted from the leg muscles of the two locust taxa were conducted. These enzymes were acid phosphatase ( Acph ), alcohol dehydrogenase ( Adh ), βester-ase ( β est ), malic enzyme ( Mal) and malate dehydrogenase ( Mdh ). Twenty presumptive gene loci and 26 polymorphic alleles were recorded. Acph did not discriminate between the two locust species, while the other four isoenzymes discriminated between them. Most of the alleles were monomeric, but Mal and Mdh exhibited dimeric alleles in the samples of C. tatarica . βest frac-tions were more expressed in C. tatarica , and the three enzymes βest , Mal , and Mdh discriminated clearly between the two species. The similarity coefficient that was calculated according to the number of sharing alleles between the two locusts was found to be 0.69. The isoenzyme variation presented herein seemed to reflect either their physiological adaptation or the taxonomic consequences between the two taxa. Collecting more isoenzymes for more sam-ples could have taxonomic value.