Botanical insecticides in practice: Where and why?

Mandates from regulatory agencies in G20 countries to promote pesticides with fewer adverse effects on human health and the environment have created renewed interest in insecticides based on natural products, including botanical insecticides. Commercialization of neem (azadirachtin)-based insecticides in the 1990s and pesticides based on plant essential oils in the past decade have raised the profile of botanicals and demonstrated their utility in certain pest management contexts. Though these products may lack the absolute efficacy and residual action of many conventional insecticides, they are finding increasing acceptance in situations where human health is the primary concern. These include urban environments – for control of domestic and public health pests, and controlled environments such as greenhouses. Other uses in the Northern Hemisphere include ectoparasite management on companion animals and domesticated livestock, mosquito abatement, and as personal repellents against blood-feeding arthropods. In developing countries, where regulatory pressures and enforcement are less stringent, botanicals appear to enjoy more widespread use, although this is difficult to track. Many tropical plants have insecticidal properties, are readily available locally at little or no cost, and can be used with minimal preparation. As the vast majority of pesticide-related poisonings and deaths occur in developing countries, it is in these countries that the benefits of botanical insecticides are best realized. This paper will discuss the dichotomy of applications for botanical insecticides – as niche products in highly-regulated countries and as tools for sustainable food production in developing countries.