The action of the spray is based on the natural insecticidal properties of the extract pyrethrum (species of chrysanthemum). Pyrethrum has an immediate, devastating impact on pests (paralysis and destruction). Unlike a lot of products available on the market, it does not contain any synthetic additive (PBO). This means that it degrades more quickly (caused by ultraviolet rays), making it harmless to humans and hot-blooded animals. The spray can also be used on a preventive basis, since pests tend to avoid objects treated with pyrethrum. The presence of pests in wood can often be observed after a complete generation has been developed. The holes that become visible are made by adult insects who come out in search of mates. By this stage the larvae, which cause the damage, have already dug tunnels. Pistal’ is a contact-based insecticide. Depending on the degree of infestation it may be necessary to lightly punch the surface to enable the product to penetrate.
It may also be applied with a brush or through injection. Pistal’ has been popular for some time with object conservators in Germany but is less well-known in other markets.