Table 1. Pesticides used in present study.
| Pesticide | Type and class of pesticide | Mode of action | Target pests | Water solubility in mg L-1 (log Kow at 25 °C) |
|---|---|---|---|---|
| Diazinon | Insecticide - Organophosphate | Inhibits acetylcholinesterase from breaking down acetylcholine, which leads to continual nerve stimulation (Cox, 2000; Garber & Steeger, 2008) | Lice, buffalo fly, mange; ectoparasites (APVMA, 2003; ANZECC & ARMCANZ, 2000) | 40 (3.81) |
| Fipronil | Insecticide - Phenylpyrazole | Blocks the neurotransmitter gamma-aminobutyric acid (GABA) and glutamate-gated chloride channels, causing hyperexcitation of the central nervous system (Anadon & Gupta, 2012; APVMA, 2009; Gunasekara et al., 2007; Stenersen, 2004) | Locusts, grasshoppers (APVMA, 2012) | 2 (4.0) |
| Imidacloprid | Insecticide - Neonicotinoid | Irreversibly binds to postsynaptic nicotinic acetylcholine receptors disrupting normal neural transmission (Abbink, 1991; Wismer, 2004; Stenersen, 2004) | Canegrub (Davis et al., 2008; Devlin et al., 2015; King et al., 2017a) | 610 (0.57) |
| Chlorothalonil | Fungicide - Organochlorine | Chemically reduces the antioxidant glutathione; enzymes that are dependent on glutathione, including enzymes important in cellular function, become non-functional (Cox, 1997; Raman, 2014) | Fungal diseases of cereals, fruits and vegetables (e.g. wheat, stone fruit, strawberries, potatoes) and other crops (peanuts, tobacco) (King et al., 2017b) | 0.81 (3.05) |
| Propiconazole | Fungicide – Triazole |
Inhibits ergosterol biosynthesis critical to the formation of cell walls of fungi, thus inhibiting fungal growth (USEPA, 2006) | Rice blast fungus, pineapple sett rot, rust fungi, fungal diseases of bananas, oats, peanuts, perennial ryegrass, stone fruit, sugar cane, wheat (Bhuiyan, Croft & Tucker, 2014; Garland, Davies & Menary, 2004; Pak et al., 2017) | 100 (3.72) |
Note:
Pesticides used in this study, their class, mode of action and target pests in Australia. Water solubilities and log KOW values from PubChem Database (National Center for Biotechnology Information, https://pubchem.ncbi.nlm.nih.gov/compound/ (accessed on Apr. 20, 2020)).