Here are a few toxic recipes for the nasty bugs.
Is for small pests and general plant protection. Chop 90g of raw garlic and soak in 2 tablespoons of paraffin oil for 24 hours. Slowly add 600ml of water into which 7 g of soft soap has been dissolved. Stir well, strain through butter muslin and store in a a china or glass container, (never use metal). Dilute the solution to one part in 50 to spray affected plants.
Is an organic compound sold commercially that will kill caterpillars if sprinkled on leaves. Derris is toxic to fish.
Is a commercially made bacteria to be used against caterpillars and cherry slugs and other chewing insects.
Is an excellent insecticide. Cut up 1.5kg rhubarb leaves, boil in 3.5 litre of water then cool. Dissolve 125g of soft soap in 2.5 litres of hot water. Cool, strain and blend the two liquids.
Casurina Needles - up to 9g - infused in a litre of boiling water makes a mild fungicide and protect against fungal and bacteria and mildew problems.
Can be made from chopped garlic, onions, lavender leaves and flowers, mint and yarrow - mixed together then covered with water. Stand in an airtight container for 24 hours then strain. Add equal quantities of water and a few drops of organic detergent and apply as a spray.
Is effective for scab and mildew fungi. Use about 200g of dried chives (buy in bulk at a health food store) and cover with 600ml of boiling water. Infuse for one hour, then dilute one part to two of water.
If the above doesn't work, or if they do, it is still useful to get out and look at your plants, and I mean REALLY look. Pick them up and see if any nasties have left any tracks or traces on them, then set a trap. Get the torch out in the first hour after dark, grab some gloves, your size 9 gumboots and look in the bush house and around.
Then use TREAD-EM, SQUASH-EM, and CUT-EM-UP. These I have found over the years to have a rather therapeutic effect on me and have saved a show bench flower or two as well!