Beware as these organic insecticides often have added chemicals. Pyrethrum and Derris dust are advertised as being ‘natural herbal’ insecticides, but this is sometimes misleading. Piperonyl butoxide is one of the chemicals which is sometimes added to pyrethrum. Piperonyl butoxide is a synergistic chemical which makes the pyrethrum compounds more active, but this is a toxic poison.
And remember that herbal insecticides are likely, too, to affect the bees if it is sprayed on flowering plants. So do not put any insecticide around flowering plants.
Many toxic chemicals are added to household pyrethrum sprays which are used to kill flies, spiders and ants in the house. These spray-can aerosol insecticides are very bad for the environment. These poisons are potentially carcenogenic, and are weakening to the immune system. Breathing these fumes weakens the lungs and may cause asthma and other breathing ailments to set in. It is a bad thing that many people in the ‘civilized’ world have this mind-set about killing all insects in the house, as these insects are valuable to plant life. Many of these insects are food in themselves for birds and animals. They all have a purpose and a right to live anyway, and we do not have the right, really, to go about killing these insects just for the sake of it. The Buddhist approach is the one which we should be adopting: The aim is not to kill any form of life at any time, for any reason. Sometimes it is necessary to kill animals, or insects, but we need to be mindful about what we are doing. It is best to save all creatures if it is at all possible.
Derris dust, which is derived from a plant, and is a natural insecticide, usually has chemicals added to it as well. Both Derris dust and Pyrethrum are capable of killing bees, ladybirds and butterflies or hoverflies, which is one disadvantage of using these ‘natural’ insecticides in the garden. We should all be making a concerted effort to stop using any chemicals, herbicides and pesticides, which kill bees and other garden-friendly insects. . Bee numbers, as well as those of ants and many other pollinating insects, are declining because of the poisons used in agriculture and in household gardens. Long-lasting potent chemical, which can be planted in the garden to kill ants and other insects, are promoted by the chemical companies: These are VERY POISONOUS, and are very bad for the environment. It is an especially bad concept to kill all garden insects just because you can. You interfere with the natural food chain by doing so, and deprive a bird or another insect of its food in the process.
Killing all our pollinating insects is a very serious state of affairs for mankind, as many of our food crops are reliant upon bees, ants, spiders, moths and other insects to pollinate our foods for us. The added chemicals are probably responsible for these ‘natural’ products killing bees. Apparently, Derris and Pyrethrum preparations are also toxic to frogs and toads, and to tortoises and fish, so their use must be avoided near waterways and ponds. Do not use these ‘natural’ insecticides anywhere near your fish pond or your tortoise tank. In fact, it is better to use less harmful alternative methods to keep those insects at bay, rather than use derris or pyrethrum products.
Use Marigolds Instead of Pyrethrum and Derris Insecticides: Marigolds are the heaven-sent deterrent to unwanted pests. Companion planting Marigolds amongst your tomatoes and cabbages, your potatoes and beans, is a far better solution to controlling garden pests than using derris dust or pyrethrum preparations. Marigolds are a natural insecticide which will not harm bees or moths. It does not directly kill the troublesome insects, but instead it repels and discourages them. Marigolds will help to deter those unwanted garden insects such as white butterfly, and wire worm in potatoes, but they are helpful in encouraging those other insects which are beneficial for the pollination of plants. Bees love marigolds.