Cantharidin Component of Iranian Blister Beetles (Col: Meloidae) and their differences between Iranian and Exotic Species

Cantharidin is one of the most well- known compounds which has ever been fascinating in medicine due to its effects on human and domestic animals. It is produced naturally by beetles of family Meloidae and Oedemeridae, however a considerable spectra of other insects sequestered it too. Cantharidin along with the other analogue, Palasonin, which has a methyl group less than it, found in the hemolymph and all tissues of both cantharidin producing and cantharipilous taxa. Although, palasonon mostly found in low volume, some species bear it even in a higher amount than cantharidin; thus it may be regarded as a precursor for cantharidin synthesis in producing taxa. Measuring titre of both chemicals in Iranian blister beetles from Nahavand county, Hamedan Province and some other species from France, Italy and South Africa, we have tried to have an index to differentiate species or at least different poulations of the same species as it has already done for family Staphylinidae. In this way, cantharidin may not be a good inicator, but it seems more effective along with other analogues, chemicals and some simple physiological information. Cantharidin/Palasonin ratio (C:P) is a better index which seems efficient in dividing European species from similar South African ones. Palasonin itself can be used to diffrentiate Iranian species from all other studied groups. More chemicals used in this new developed method, more precise is the classification.