Types and Classification of Insecticides
– Insecticides are pesticides used to kill insects.
– They include ovicides and larvicides used against insect eggs and larvae, respectively.
– Insecticides can be classified into two major groups: systemic insecticides and contact insecticides.
– Systemic insecticides travel through the plant after uptake, while contact insecticides are toxic to insects upon direct contact.
– The mode of action describes how the pesticide kills or inactivates a pest.
– Insecticides may be repellent or non-repellent.
– Examples of systemic insecticides include plant-incorporated protectants (PIPs) produced by genetically modified plants.
– Contact insecticides can be inorganic or organic, including synthetic compounds and natural compounds like pyrethrum and neem oil.
Synthetic Insecticides
– Synthetic insecticides include various chemical compounds such as organochlorides, organophosphates, carbamates, pyrethroids, neonicotinoids, phenylpyrazoles, butenolides, and ryanoids/diamides.
– DDT is a well-known organochloride insecticide.
– Organophosphates target the insects’ nervous system.
– Carbamates have a shorter duration of action and are less toxic than organophosphates.
– Pyrethroid pesticides mimic the insecticidal activity of the natural compound pyrethrin.
Biological Pesticides and Alternatives to Chemical Insecticides
– Natural insecticides derived from plants and other natural sources are being researched as alternatives to common chemical insecticides.
– Commercially used plant extracts include pyrethrum, rotenone, neem oil, and various essential oils.
– Biological approaches to pest control include the use of Bacillus thuringiensis bacteria, RNA interference, spider venom peptides, and plant enzymes.
– Breeding pest-resistant crops, releasing predators and parasitoids, using pheromones, and implementing Integrated Pest Management techniques are alternative methods to chemical insecticides.
Environmental Impact of Insecticides
– Insecticides can harm non-target species, such as birds and wildlife, and alter ecosystems.
– DDT, a now-banned insecticide, caused thinning of eggshells in predatory birds and reduced bird populations.
– Insecticides can bioaccumulate and biomagnify, causing higher concentrations in animals higher up the food chain.
– Runoff and percolation of insecticides into water bodies can harm water quality and affect natural ecology.
– Insecticides may contribute to pollinator decline, including the loss of bees and colony collapse disorder.
Integrated Pest Management (IPM) and Sustainable Pest Management Strategies
– IPM is a sustainable approach to managing pests that combines biological, cultural, physical, and chemical control methods.
– Push-pull strategies, natural insecticides, and bee-friendly pest management are components of IPM.
– Sustainable pest management strategies include crop rotation, conservation of natural habitats, mating disruption, trap crops, and agroecological practices.
– Challenges and future directions in pest management include developing new insecticides with lower environmental impact, researching pesticide mixtures and synergistic interactions, genetic engineering for pest-resistant crops, promoting organic farming practices, and raising public awareness about sustainable pest management.
– Resources and organizations in IPM include the University of California Integrated Pest Management Program, the Insecticide Resistance Action Committee (IRAC), the International Pesticide Application Research Centre (IPARC), and the National Pest Management Association (NPMA). Source: https://en.wikipedia.org/wiki/Insecticide
