 The milk cap 's fruit bodies have a characteristic orange milk juice ( latex ) . The <unk> sesquiterpenes are responsible for the orange colour . Sesquiterpenes are terpenes composed of three isoprene units and therefore have 15 carbon atoms . Sesquiterpenes are widely distributed in nature and are found in plants as well as animals , for example in the juvenile hormone of insects . Plants use sesquiterpenes as a defense compound against insects . According to some studies , sesquiterpenes have antibiotic , <unk> , or <unk> effects . 
