When the Spanish arriving in South Amercia and saw the native people producing a rich range of reds and purples, they could hardly believe their eyes as the reds and purples they saw had been both rare and expensive in Europe. They regarded the cochineal beetle as a gift from God not realising that the native people had been cultivating it for 1000's of years. The Spanish imported vast quantities of cochineal into Europe the income from which rivalled silver as a source of wealth as cochineal was both very much cheaper than the native red insect dye kermes and more potent a dye.
The colours from cochineal are rich and warm; pinks, reds, purples or grey. The colours vary depending on both mordant and pH (that is whether acid or alkali is added such as acetic acid or sodium carbonate ( washing soda) or ammonia).
For more information read Colours of the Earth by Helen Melvin available from this website
10g will dye 50g of fibres a deep pinky red colour on an alum mordant, but dont forget to add cream of tatar as cochineal only fixes well in an acidic environment or do as the pervuvian do and add a cut up lime to the bath instead and successive exhaust baths give paler and paler pinks till the dye is exhausted.