the demand for cochineal fell sharply with the appearance on the market of alizarin crimson and many other artificial dyes discovered in europe in the middle of the 19th century, causing a significant financial shock in spain as a major industry almost ceased to exist. the delicate manual labour required for the breeding of the insect could not compete with the modern methods of the new industry, and even less so with the lowering of production costs. the ""tuna" blood" dye (from the mexican name for the "opuntia" fruit) stopped being used and trade in cochineal almost totally disappeared in the course of the 20th century. in recent decades, the breeding of cochineal has been done mainly for the purposes of maintaining the tradition rather than to satisfy any sort of demand. however, the product has become commercially valuable again. one reason for its popularity is that many commercial synthetic red dyes and food colorings have been found to be carcinogenic.