Respiratory disrupting insecticides
Respiratory disrupting insecticides are one of five ways insecticides work.
The lungs and respiratory system are targets of respiratory disrupting insecticides. Many of these insecticides are based on microbes or microbial compounds.
They can be fast acting.
One example of a respiratory disrupting insecticide is Chlorfenapyr. This is a chemical derived from a class of microbial produced compounds. Chlorfenapry was denied registration for use on cotton in the USA in 2000 because it was toxic to birds and there were less lethal substitutes. However, it was registered only one year later in the USA for use in greenhouses. According to the USA Environmental Protection Agency, it has subsequently been registered for use on cotton.
In Australia, it’s registered under a number of brand names. One of these is Intrepid 360 SC Insecticide-miticide. It’s registered for use on bollworm, native budworm and the two-spotted mite on cotton. The label states that the mode of action is in the stomach, rather than the respiratory system as suggested by the Insecticide Resistance Action Committee (IRAC).
The label also says that it’s dangerous to aquatic and terrestrial organisms. It kills, among others, fish and bees and the label says it may affect other insects, bird and native animals. So much for the precautionary principle!
I have had the two-spotted mite on clients plants. I didn’t need a toxin like this. After doing some research I found horticultural oil works. Horticultural oil is a respiratory disruptor and works by suffocation.
Once I realised that, I did more research. I found that mites thrive in hot conditions but their numbers fall after rain. So when it’s hot and it hasn’t rained, I’m on the look out for mites. Where I see an infestation, I emulate rain by using a hose! I tried it, and it works at treat. That’s now my commercial remedy for mites.
We can use harmless water or this toxic chemical. Sure, this is for cotton use only and therefore for farmers… but where there are other means available such as water, shouldn’t we use them?
Read the next blog in this series: stomach and midgut affecting insecticides.