Pests

How to deter and get rid of slugs, snails, aphids & other pests from your garden.

There are two main groups of pests, based on how they cause damage. They are chewing pests and sucking pests.

Chewing pests such as caterpillars, which are the larval stage of butterflies or moths, chew holes in the leaves. Grass grubs, which are the larval stage of beetles, eat the roots of the turf, causing die-back. Adult beetles are the other major group of chewing pests. Lemon tree borers or leaf miners chew their way through the inside of stems and leaves. This can cause die-back in the case of the lemon tree borer, which also affects other plants. On plants such as kaka beak, leaf miners cause unsightly tunnels in the leaves.

Sucking and rasping pests include aphids, which suck the plant sap from inside the leaf, or thrips, which rasp and then suck the sap from the underside of the leaves. These pests can congregate on leaves, stems or even roots. They typically cause distortion, such as the puckering of by psyllids on karo leaves, or silvering of leaves as the sap from the leaf surface is removed by thrips.

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Ants

Ants do not damage plants directly but sometimes steal freshly sown seed from garden beds and seed boxes. They also collect the sweet liquid known as honeydew, which is excreted by aphids and some other sap-feeding insects. Ants can protect aphids from attack by ladybirds and other predators in order to secure their supply of honeydew. Increased numbers of aphids may result in more damage to plants.

Symptoms

They do little damage to plants themselves, except by disturbing soil around plant roots and depositing it on the surface during their nest building activities. This can be a nuisance on lawns and where low-growing plants are being buried by excavated soil.

Solution

Neverong is specially formulated for the control of ants. Ants are attracted to the bait and carry it back to the colony where it kills the queen and the nest.

If you can't find the hill, sprinkle dry clothes detergent or dishwashing detergent where they can get to it. There's something about the detergent that attracts them and they carry it back to their hill. What they don't understand - it poisons them.

Ants like dry, light soils, so by applying a regular drenching of water via a sprinkler or rose watering can will make them pack up and move.

Aphids

Aphids are small, soft-bodied insects, which are usually 2 – 4 mm long. Aphids often cluster on young shoots and flower buds or underneath older leaves. There are many different species of aphids which vary in colour from green to yellow and black. Aphids attack fruit trees, roses, camellias, chrysanthemums other ornamentals and a wide range of vegetables. Aphids also transmit virus diseases such as broad bean wilt. Small colonies multiply rapidly in warm weather, and large infestations can develop in a number of days. Check your plants a couple of times a week at the beginning of warm weather so that aphids can be controlled when populations are relatively small. Look out for natural predators such as ladybirds and parasitic wasps. The tiny wasp lays eggs inside the aphid giving it a hard light brown shell like appearance. The ladybird larvae which looks like tiny bird droppings are actually voracious eaters of aphids. Both of these predators will reduce aphid numbers rapidly once they arrive.

Symptoms

Buds may fail to open and leaves are twisted and distorted. New growth may be stunted. Because aphids excrete a substance called honeydew, this provides an environment on which sooty mould fungus can grow. Removing the source of the honey dew will usually solve the sooty mould problem as well

Solution

Avoiding chemicals may encourage parasites and predators. Use Confidor, Maldison, Mavrik, Supershield or Target insecticide.

Use neem oil, garlic or onion/garlic, pyrethrum or soapy sprays. Attach yellow sticky traps.

Hose off insects or squash them with your fingers.

Nasturtiums planted nearby will lure away aphids.

Suitable plants to attract predators and parasites include blue tansy, coriander, cosmos, lavender, sunflower, and yarrow.

Try using washing up liquid mixed with water. Then spray onto the infested area. Another way is to remove the aphids by hand on a regular basis.

Borers

There are virtually hundreds of different kinds of wood boring insects. Some are caterpillars of moths or butterflies, some are larvae of beetles, some are sawfly larvae, and still others are weevil grubs. Borer damage is not caused by the adult itself but by the larvae which bore into the phloem and cambium layers after emerging from their eggs on the bark. The borers’ tunnelling weakens and kills trees by interrupting the flow of sap. The entire life cycle of the borer is one year from egg to beetle. Borers are attracted to trees that are under some type of stress. Newly planted trees should be properly watered and fertilised during the first few years of growth to prevent any borer attack. Healthy trees can ‘drown’ borers by engulfing them in sap.

Symptoms

Trees with frass or webbing around a hole in the trunk or limb indicates borer presence. These grubs attack the sapwood of the tree.

Solution

Natures Way Pyrethrum controls a wide variety of insect pests on vegetables, flowers and ornamentals.

Planting garlic around the base of trees is said to repel borers. Try it but don’t rely on it.

Cabbage Moth Cabbage Butterfly

There are many types of caterpillars which are usually the larval (caterpillar of a grub) stage of moths such as cabbage moth and small cabbage white butterfly. Cabbage white butterfly is white with distinct black spots on the wings and is around 40mm across. The cabbage moth is greyish and small and is around 10mm across. The moths and butterflies lay their eggs on the underside of leaves. The larvae of caterpillars hatch from the eggs and then feed on the leaves or fruit, so it’s the caterpillar of the cabbage white butterfly or cabbage moth which does the damage. The blue-green smooth textured caterpillar is that of the cabbage white butterfly, while the caterpillar which is green-brown is that of the cabbage moth. They both start eating the outer leaves before moving to the inner heart of the cabbage. It is a good idea to try and either pick off the caterpillars or spray them when they are still on the outside of the leaf, before they tunnel into the heart. Plants favoured by cabbage moth and cabbage white butterfly include cabbage, broccoli, Brussel sprouts, Chinese cabbage, celery, beetroot, rocket and watercress.

Symptoms

Large holes in outer leaves. Bluey-green frass on the inside of the leaf or in the heart of the cabbage, which is actually their droppings.

Solution

Mavrik Insect & Mite Spray controls a broad range of insect and mite pests, yet will not interfere with honey bees once the spray has dried. As a result Mavrik is excellent for use on flowering plants.

Carrot Rust Fly

Carrot rust fly is a small (to 6mm) shiny, black fly with a reddish head and yellow legs. The cream or white maggot-like carrot rust fly larvae causes damage, first by eating the root hairs of young plants and then burrowing into the carrots or parsnips as they develop. Carrot and parsnips, with their tasty roots, are the crops most likely to be affected, but this pest can also attack related plants like parsley and celery. Flies begin laying eggs next to the host plants in spring. Reduce the chances of attack by rotating crops (don’t plant carrots and parsnips where they’ve been grown for a few years), keeping the area weed free, putting up a barrier (like shadecloth) to deter flies, and by planting carrots with onions which are said to deter the pests.

Symptoms

Partial dieback with yellowing, or the whole plant can turn brown and die due to internal feeding. In carrots the young plants are attacked on the taproots and may die, leaving gaps in the crop. Larger carrot plants are attacked at the base of the taproot and lower down, showing irregular brown channels under the surface, from which the creamy-white larva (maggot) can be extracted. Where damage to plants is severe, the leaves become reddish and the plant may die, particularly if stressed from dry conditions. In parsnips the damage is similar to that on carrots, but usually it is confined to the top 15 cm of the root. In celery the larvae bore into the roots, crown and petioles, resulting in yellowing of the leaves and a reduction in growth or death of young plants. In parsley the larvae live in the surface of the taproot and in the lateral roots.

Solution

Yates Soil Insect Killer controls insect pests in the soil and around rubbish heaps and buildings.

Caterpillars

There are many types of caterpillars which are usually the larval (caterpillar or grub) stage of moths and butterflies, such as cabbage moth, cabbage white butterfly, potato moth or tomato moth. The moths lay their eggs on the underside of leaves. The larvae of caterpillars hatch from the eggs and then feed on the leaves or fruit. Another kind of caterpillar is the armyworm or cutworm, which is brown or green (or sometimes striped) and mostly feeds at night. These caterpillars cut through the stems of seedlings or transplants, and can also attack lawns. The parent moth rarely does any damage and is not often seen as they mainly fly at night.

Symptoms

Holes are seen in the leaves or fruit. Holes are usually irregular in shape. Black or brown droppings can also bean indication of the presence of caterpillars.

Solution

Yates Insect Gun Ready To Use is a natural insecticide for indoor plants and ornamentals growing outdoors for the control of caterpillars, aphids, white fly and a wide range of insects.

Cut Worms

Cutworms are caterpillars of night-flying moths that lay their eggs in the soil. After the caterpillars emerge they chew young plants and seedlings at ground level, sometimes eating right through the stem, which falls over (hence the name cutworm). The caterpillars grow up to 40mm long and range in colour from light grey or pinkish brown through to almost black. If disturbed they curl up into a flat coil. They eat at night and take shelter in the soil during the day. They usually attack seedlings but can also affect soft fruits like strawberries. Cutworms are more likely to be active after periods of rain.

Symptoms

Young garden plants severed at or near the soil surface, usually overnight. Some cutworms feed on foliage, buds, or fruit, and others feed on the roots.

Solution

Yates Insect Gun Ready To Use is a natural insecticide for indoor plants and ornamentals growing outdoors for the control of caterpillars, aphids, white fly and a wide range of insects.

Prevent cutworm attack by placing small, open-ended plastic cups around plants or by wrapping plant bases with aluminium foil. Cutworms are only active at night, so go out after dark with a torch and check for caterpillars at work.

Install collars around seedlings to act as a barrier to cutworms. Push one end into the soil a few inches, and allow the other end to extend above the soil surface. Cardboard toilet paper rolls can work well for this. 

Plant a perimeter of sunflowers around your garden to act as a trap crop for cutworms. Monitor the sunflowers for cutworms and destroy them as you find them.

A sprinkling of cornmeal or bran throughout the garden will be devoured by them and they die.

Make trenches 3-4 inches wide by 2-3 inches deep. Fill these with crushed eggshells.

Sink screws or nails in the soil next to plants stems to prevent them wrapping around and cutting.

Grass Grubs

Grass grubs are the larvae of dark brown shiny scarab beetles that lay their eggs in the soil in spring and summer. After the larvae hatch they begin feeding on grass roots. The grubs pupate in winter and emerge as beetles the next spring . The grubs can also eat the roots of vegetables and other desirable plants. Grass grubs are C-shaped, creamy-white and have slightly darker heads. Adult beetles feed on above ground plant parts and can cause problems if they’re present in large numbers.

Grub numbers can be reduced by removing any that are found when digging garden beds. Scarab beetles are attracted to light so, where possible, turn off outside lights whenever the beetles are active.

Symptoms

Brown patches of dead grass and grass that lifts from the soil like carpet. An unusual number of birds pecking at the lawn looking for the tasty grubs can also be signs of grubs.

Solution

Yates Soil Insect Killer controls insect pests in the soil and around rubbish heaps and buildings.

Green Vegetable Bug

The green vegetable bug is bright green in colour and about 1.5 cm long in adulthood, but more rounded and black and white or black and red in younger stages. It attacks beans, tomatoes, potatoes, sweet corn, vine crops, grapes, sunflowers and other ornamentals and is mostly active in hot weather. The green vegetable bug sucks the sap of stalks and leaves and the juices from fruit. Like the bronze-orange bug, if disturbed, the green vegetable bug will emit an unpleasant chemical which has a strong odour and can stain fingers and clothes.

Symptoms

Wilting shoots from sap loss. Fruit distortion and shrivelling or for tomatoes, hard corky growth.

Solution

Natures Way Derris Dust controls most chewing and sucking insect pests, including caterpillars, on vegetables and flowers. It is particularly effective against white butterfly and diamondback moth caterpillars. It is also helpful in the control of aphids.

Leaf Hopper

Leaf hoppers are small, quick-flying insects. They are usually green, yellow or brown and their sap-sucking feeding causes mottling of leaves. They attack many plants and can also transmit virus diseases. Their sticky waste (called honeydew) sometimes grows black sooty mould fungus.

Appearance of leaf hoppers can vary. Young leafhoppers (nymphs) tend to have tufty ‘tails’. Some species of adults fold their wings close into their bodies but others have outspread wings that make them look like small butterflies. All hop away quickly when disturbed.

Symptoms

Feeding and egg laying cause damage, e.g. curling, stunting, and dwarfing, to the infested plant. The leaves turn yellow, or sometimes pink or purple, and become wilted or stunted. Later, the leaf becomes brown and dies.

Larger nymphs cause most of the damage. The injection of saliva into the phloem during feeding by potato leafhoppers may cause disease-like symptoms. Infested plants may exhibit a condition known as "hopperburn" in which there is a distortion of the leaf veins, a subsequent yellowing of tissue around the margin and tip of the leaf, and eventually a rolling and curling inward of the leaf. Floral development may be reduced or obstructed completely.

Solution

Yates Insect Gun Ready To Use is a natural insecticide for indoor plants and ornamentals growing outdoors for the control of caterpillars, aphids, white fly and a wide range of insects.

Leaf rollers

Leaf rollers are a group of caterpillars that tie leaves around themselves with silken threads and eat the leaves from within this shelter. They are found on a number of different plants, including a wide range of fruits and ornamental shrubs and trees. They can cause damage to the outer surfaces of avocadoes, kiwi fruit and others.

Leaf rollers can be removed by hand when they’re first seen but if their numbers increase, other controls may be necessary.

Symptoms

Moth larvae form feeding shelters by spinning silk webs around young leaves and rolling them together. Single leaves may also be rolled into tight cylinders. The larvae may skeletonize the leaves, (only the veins remain intact) or consume them whole. Severed leaf segments remain within the silk webbing and become bleached or brown.

Solution

Yates Success Naturalyte Insect Control controls various caterpillars on fruit and vegetables.

Remove mummified fruit from trees in winter. A clean-up spray of Conqueror Oil in winter will help reduce numbers of over-wintering eggs on deciduous trees.

Pear & Cherry Slug

Pear and cherry slug (also called pear slug, or cherry and pear slug) is not a slug at all but the slimy-looking, brown to black, slug-like larvae of a sawfly. The female fly lays eggs into the leaves of pears, cherries, apples, quinces and their ornamental relatives such as flowering plums and hawthorns. After the larvae hatch out they begin to graze on the leaf surfaces. They gradually eat the upper surface of the leaf, leaving only a network of veins. They then pupate in the soil until the adult flies emerge to begin a new cycle. Sometimes the larvae over winter in the soil beneath the trees, so soil cultivation at that time of year gives some control.

Spraying with an insecticide is most effective when the larvae are young. Infestations on small trees can be removed by hand.

Symptoms

Their presence is noticeable by the tunnels they leave as they emerge at night to feed on grass. Their tunnels are associated with bare patches of pasture, and dead plants along with increased incidence of flat weeds. Tunnel entrances can be found as holes, covered in soil castings and debris held together with silken threads.

Solution

Natures Way Pyrethrum controls a wide variety of insect pests on vegetables, flowers and ornamentals.

Porina Caterpillar

Porina caterpillars feed on lawns and pasture grasses. The adult moth lays its eggs (usually in spring) on the grass and, after hatching, the small caterpillars first take shelter among the leaf bases. As the caterpillars grow larger they begin to dig burrows in the soil. At night they emerge from these to feed on grass leaves. They are at their largest and most damaging in autumn and early winter.

The brown adult moth takes flight at dusk and is particularly attracted to lights, so reducing outdoor lighting in spring will reduce their effects. Keep lawn well fed and in good condition. Mow well in summer to expose young larvae and remove any thatch that may provide the caterpillars with shelter.

Symptoms

You will see yellowing of the leaf along with bare patches with fine soil casts appearing.

Solution

Yates Soil Insect Killer controls insect pests in the soil and around rubbish heaps and buildings.

Rats & Mice

Rats and mice cause major damage to agricultural crops by eating newly-sown seeds, young plants and seed heads on grain crops. In the home garden they can cause similar damage and have also been found to eat starchy plant parts such as bulbs or swollen roots. Rats and mice are ecologically damaging because they compete with many native species for food and habitat, and eat birds’ eggs and young lizards.

Symptoms

Flattened grass, plants and other vegetation where rats and mice have created their own pathway.

Solution

Racumin Rat and Mouse Paste kills rats and mice. Baiting is necessary for at least two weeks to reduce rat and mouse numbers.

Scale Insects

There are two main groups of scale insects, both of which spend most of their lives as immobile adults under a coating, sucking the sap from stalks, leaves and stems. Hard scale (for example red citrus scale) has an oyster like coating and is difficult to control. Soft scale (for example pink wax scale and soft brown scale) are usually found on the mid-rib of leaves and stalks of host plants. Most common is white wax scale, seen as large patches of white waxy material along the stems and shoots. The wax covers the insects which feed on the sap. The adult scale lays up to 1000 eggs that hatch into crawlers. These crawlers move to a nearby feeding site where they set up home feeding on the sap of the plant. It is at this crawler stage the scale is most vulnerable as there is no waxy coating to protect them. Spraying with Yates Conqueror Oil at this stage will give good results. There are many different types of scale and some scale insects are host specific, such as rose scale, white palm scale, gum tree scale and tea scale (camellias.) Others attack a variety of hosts such as white wax scale occuring on gardenias and citrus; and cottony cushion scale occuring on figs, rose, magnolias, grevilleas and citrus.

Symptoms

White patches on stems or pink or brown raised dome like structures on leaves and stalks about 3-5mm. Sooty mould grows on the honeydew the scale insects secrete. Scale can cause death of stems if infestation is heavy.

Solution

Yates Bug Oil Conqueror Oil Insect Spray Ready To Use is a ready-to-use insect spraying oil for the control of scale, mites, aphids, white fly and mealybugs on roses and ornamentals.

Snails and Slugs

Slugs and snails are members of a large group which counts molluscs as its members. Slugs and snails are soft bodied animals with or without a shell and not segmented. They prefer moist environments and live off decaying animal matter, algae, and plant material such as leaves and stems. These pests are most active on cool, wet and humid nights.

Symptoms

Silvery trails which can dry to appear like gold dust. These trails are the mucus they secrete in order to move. Holes in leaves of plants and seedlings chewed off at the base.

Solution

Blitzem Snail and Slug Pellets kills snails & slugs by dehydration.

Crushed eggshells are bad on the slugs, and the shells also add nutrients to the soil. Birds like eggshells because they add calcium to their diet so the eggs they make are stronger, and if a bird is eating eggshells happens to see a bug, well you can imagine what will happen to the bug.

As you know slugs love to party at night so why not treat them by supplying the drinks. Place a pint glass with some beer in it on it's side where they hang out . The next morning you will find lots of dead slugs , but at least you gave them a good farewell party. Birds will eat the corpses and be will be singing merrily all day long.

Thrips

There are 7,400 species of thrips in the world and quite a few are serious pests of plants. Some of the more commonly known thrips are Greenhouse thrip, Western Flower Thrips and Plague thrips. Thrips are 0.5mm – 15 mm long and range in colour from white to yellow to black. Thrips generally have wings that are fringed but this can only be seen with magnification. Thrips attack the flowers, fruit and foliage of a variety of plants. Roses, fruit trees, azaleas, gladioli and a variety of vegetables such as tomatoes, onions and beans all suffer from thrip attacks. Thrips lay eggs inside plant tissue and the pupae feed on plant juices. Thrips also lay eggs in unopened buds making it difficult to control the insect. Thrips also spread plant viruses; for example tomato thrips and western flower thrips spread the tomato spotted wilt virus.

Symptoms

Thrips scrape the surface of the leaves and petals, and suck the sap, leaving a white mottled appearance on leaves. Other symptoms are browning on petals and fruit, and flower drop. If left unchecked the leaves, new shoots and flowers will become deformed and stunted. Wilting and browning can also occur.

Solution

Yates Bug Oil Conqueror Oil Insect Spray Ready To Use is a ready-to-use insect spraying oil for the control of scale, mites, aphids, white fly and mealybugs on roses and ornamentals.

Spray plants with neem oil in the morning 2 times 3 days apart.

Keep your plants properly watered and mist them if you can, thrips hate moisture.

Two Spotted Mite

Mites are related to spiders as they have four pairs of legs. Tiny pinkish-red mites cluster on the underside of leaves often producing fine webbing. Two spotted mites over winter in protected places. Two spotted mites are active in hot dry weather when the life cycle from eggs to adults is completed in a week. For this reason, mites can develop resistance to pesticides fairly quickly. The mites dislike moist humid conditions so overhead watering can be useful as a control. Mites are often found on plants that are growing in dry situations, (e.g. indoors.)

Symptoms

Yellow mottling or bronzing of the leaves similar to lace bug damage. Significant distortion of flower and leaf buds. Fine webbing can be seen on heavy infestations. Severe infestations can cause defoliation of affected plant parts.

Solution

Yates Mite Killer controls European red mite and two spotted mite by contact action on a range of plants, including fruit, vegetables and ornamentals.

Whiteflies

Small white winged sap-sucking flies that are not true flies. They resemble tiny white moths with a wingspan of 3mm. Whiteflies have become very prevalent in recent years and there are several different types which are major pests for home gardeners. The silverleaf whitefly and the greenhouse whitefly. If the plant is disturbed, a cloud of tiny insects fly out but they soon settle back onto the same plant. Both the adult and juvenile (nymph) whiteflies suck the juices from the plant. Favoured plants are hibiscus, poinsettia, gerberas, herbs such as sage and mint, vegetable seedlings such as squash, melon, eggplant, cabbage and bean, tomato and broccoli.

White fly are best controlled using alternating sprays such as Confidor, Target, Natures Way Pyrethrum and Super Shield (depending on the plant being edible or not), as the insects can build up chemical resistance very quickly. Alternating insecticides help to prevent this from happening. Spraying is best done in the early morning or late afternoon when the insects are more restful.

Symptoms

Wilting and stunting of new shoots. Can cause silvering and yellowing of leaves (eg. squash) and uneven ripening of tomatoes and sometimes plant death. Sooty mould often accompanies large numbers of white flies as they excrete honeydew when feeding on plant tissue.

Solution

Natures Way Pyrethrum controls a wide variety of insect pests on vegetables, flowers and ornamentals. Sprays containing pyrethrum or neem offer some control to existing whitefly infestations. Coat both the upper and lower surfaces of leaves. Repeat applications will need to be made.

Monitor for whiteflies with yellow sticky traps. Hang or mount the traps near your plants and check often. These traps will not only tell you if you have a whitefly problem, they will also catch quite a few of them.

Small infestations can be washed off with a blast of water or by sinking the plant in a bucket of water.