Natural insecticides suggested for specific pests

Ants	Pour boiling water or pure lemon juice directly onto the nest. Check for aphids, because they produce a sort of honeydew that attracts ants.
Aphids	Cayenne pepper solution. Clay. Dislodge aphids by spraying perennials, shrubs and trees with a strong stream of water. Cut off severely affected plant parts. Garlic maceration or solution. Insecticidal soap. Petunia or marigold tea. Rhubarb leaf solution.
Cabbage maggot	Garlic solution.
Cabbage worms	Salt solution. Sprinkle cayenne pepper onto broccoli, cabbage and cauliflower plants. Tomato-leaf solution.
Carrot rust fly	Garlic solution.
Caterpillars	Clay. Insecticidal soap. Petunia or marigold tea. (Rhubarb): VPour boiling water over a few rhubarb leaves. Let steep for 24 hours. Strain and combine a few drops of this mixture with 1 tsp (5 ml) of lemon-scented liquid dish soap, 1 tsp of Listerine and 1 tsp of ammonia (lemon-scented is best). Add 5 ml of this concentrate to 1 litre of water and spray on plants twice a week.
Leaf beetles (striped or spotted)	Spray onto and pour around the base of pumpkin, zucchini and cucumber plants. Stir a handful of lime or wood ash into 8 litres of water.
Leafhoppers	Garlic potion.
Leaf miners	Rhubarb leaf solution.
Lily leaf beetles	Blend 2 Tbsp of rubbing alcohol with 1 litre of insecticidal soap solution. Spray onto plants every 3 to 5 days until the insects have disappeared.
Plant bugs	Garlic potion.
Potato beetles	Citrus peel.
Scale insects	Cayenne pepper solution.
Scale mites	Garlic maceration.
Slugs	Garlic potion. Partially bury containers full of beer around your garden: the slugs will be attracted to the smell of the beer and will drown in it. Place crushed egg shells around the base of affected plants. Spread dolomitic lime around your vegetable garden or wood ash between rows.
Spider mites	Apply a solution of 2 litres of water mixed with ½ cup (250 ml) of sugar. Macerated garlic. Rhubarb leaf solution. Spray on plants once in springtime to dry out the mites.
Thrips	Garlic solution. Insecticidal soap.
Whitefly	Garlic potion.