a substance or mixture of substances represented as suitable for eradication or control of:
a. any unwanted mammal, bird, reptile, amphibian, fish, insect, anthropod, mollusc, nematode or other worm, plant or fungus, not being an organism living on or in any man or any livestock; or
b. any bacterium or virus affecting plants; whether by way of modification of behaviour or development or otherwise; and includes any substance or mixture of substances represented as suitable for use as a plant growth regulator, or a defoliant, or as a desiccant; but does not include a fertiliser, or an animal remedy within the meaning of the Animal Remedies Act 1967.