Aphids
These tiny sucking insects attack the soft new growth of anything from lettuce to roses and eucalypts. Aphids are quite remarkable insects. They are almost exclusively female, do not require males for breeding and give birth to prodigious numbers of live young. They appear in plague proportions when conditions are mild, but disappear just as quickly in extremes of temperature. Spring sees an explosion in aphid populations, but hot weather and windy conditions are enough to dispatch them. Soap sprays, oil sprays see [Do It Yourself Pest Control-Oil Spray] or a strong jet of water can help to reduce numbers until voracious ladybirds discover and eat their way through entire colonies.

Borer
There are several different species of insects especially beetles and moths whose larvae attack a wide range of trees and shrubs. Plants stressed by drought and lack of nutrients are most likely to fall victim. Entire limbs can appear to die overnight. Look for evidence of sawdust-like frass that indicate active larvae. Where limbs remain green it may be possible to skewer grubs with thin wire or syringe oil-based compounds into borer holes, then seal the tree wounds with clay or wood putty. In most instances, you will need to prune the affected limb back below the point of borer activity. Assist plants to recover by alleviating stressful conditions.
More Pictures of Borer [Citrus Borer] [Borer in Murraya]

Bronze Orange Bugs
The eggs of these sucking insects lay dormant over winter, emerging as tiny, green nymphs when it warms up. Bronze orange bugs or stink bugs, change colour from yellow to orange as they grow and have a distinctive black spot on their backs. Mature insects are dark brown to black. They cluster in groups on new growth and flower and fruit stems, feeding through a sucking proboscis. This causes new growth to die back and flowers and developing fruit to drop.

If picking them off by hand, wear gloves and eye protection. These bugs secrete a caustic, acrid substance. Use a leaf blower or an old vacuum cleaner to suck them off. Oil sprays are also effective, especially on nymph stages.

Camellia Tea Mite
Camellias provide great flower colour during the cooler months in many parts of Queensland and Northern New South Wales. But just when you expect them to look their best, the foliage can develop a bronze discolouration down the central midrib of the leaf, signalling attack by camellia tea mite. Left unchecked, bronzing envelops the entire leaf and poor growth and reduced flowering result.

A simple oil spray applied to both sides of the leaves will bring the problem under control, but do not expect affected leaves to regain their former appearance. Regular use of fish based fertiliser can also help prevent the problem. The fish oil contained in the fertiliser often leaves sufficient oil residue on the foliage to control mite outbreaks. You can also make your own oil spray [refer to 'Do It Yourself Pest Control'].

Crinum Grubs
These tiny caterpillars burrow into the centre of crinum lilies, eating out the succulent heart of the plant. But don’t make the mistake of thinking their diet is limited to crinum species. They find hippeastrum, clivea and agapanthus equally appealing. Over the autumn and winter period, crinum grubs can eat out the heart of plants. What remains simply rots away. Clear away any old foliage and drench the centre of plants with molasses and water (1 tblspn per litre water). The drench should come in contact with the grub. Retreat regularly as moths revisit plants to lay new infestations.

Curl Grubs
When digging the garden or making compost you may come across larvae that are white in colour, have a characteristic ‘C’ shape, three pairs of legs and a distinctive head and abdomen. Commonly known as curl grubs, they are beetle larvae (including Christmas beetles, cane beetles, dung beetles, flower scarabs and rhinoceros beetles). The larvae vary in size with the large rhinoceros beetle larvae (pictured) growing up to 70mm long. 

The beetles lay their eggs in the soil during late spring, summer and early autumn. The eggs hatch into larvae that feed on plant roots or decaying organic matter. The larvae grow and pupate during late autumn, winter and early spring. Curl grubs are favourite bandicoot fare and small conical holes in lawns or larger excavations within gardens are the telltale signs of bandicoot activity. Wasps also parasitise curl grubs by piercing the skin and laying their eggs inside. The young wasps hatch and live inside the body, eating the non-essential tissues of the curl grub before finally emerging through the body wall of the larvae and ultimately causing its death. Larvae of the African black beetle and scarab cockchafer that attack lawns may warrant control. Products based on tea tree oil are effective or drench the affected areas with molasses spray. [refer to 'Do It Yourself Pest Control'].

Dodder
The appearance of yellow or orange cotton-like threads covering roadside grasses, signals the seasonal return of the parasitic plant known as dodder. Seeds are distributed by birds and the plant is frustratingly difficult to get rid of. Germinating seeds attach themselves to living plants, drawing on their host for nutrients. They can also carry out their own photosynthesis. This dual nutrient source explains why dodder is able to grow so quickly. The only option for control of dodder is complete removal. Dodder invades the tissue of the host plant in order to feed from it. If plants in your garden become unwitting hosts to an infestation of dodder, severe pruning or complete removal of your treasured garden plant is the only option for eradicating the parasitic pest.

Fruit-Sucking Moth
When near ripe fruit develop soft spots that cause premature ripening, fruit fly is often to blame. Breaking open the fruit will reveal tell-tale larvae that help to confirm the diagnosis. When no larvae are present, suspect attack from the fruit-sucking moth. As moths are active at night, few gardeners ever encounter them.  Fruit-sucking moths are large, with a wingspan of 5-6cm. The wings are typically dark brown with distinctive orange markings. The moths pierce the skin of pawpaws, tomatoes, citrus, persimmons, bananas and other fruit, then suck out the liquid contents. A black spot remains at the point of entry, with flesh around this either becoming soft and pulpy or dry and pithy, depending on the fruit attacked.

Spraying to control moths is not an option.  In some cases it is possible to pick fruit before it is fully ripe, thereby beating the moths to the harvest. For crops that require a greater degree of ripening, try covering fruit with paper bags or cotton cloth secured with a clothes peg. If you have an outdoor light designed to zap night flying insects, leave it on overnight. Many gardeners report significant reductions in the incidence of pest problems caused by adult moths, caterpillars and beetles using this method.

Harlequin Bugs
Cotton harlequin bugs can be found on members of the cotton or Malvaceae family. This includes hibiscus, malvaviscus, abutilon and mallow.  The metallic blue sheen of these bugs makes them easy to spot, particularly as they congregate in large numbers. The large, comparatively dull coloured, orange females tend to be solitary. Female bugs lay groups of pale pink eggs in neat clusters that encircle the stem. You will often find her standing guard over newly laid egg clusters. Like all bugs, cotton harlequins are equipped with a long, sucking proboscis. They use this tube to pierce the leaf surface and draw out the liquid contents of the stem and leaf cells. Cotton harlequin bugs rarely warrant control. Occasionally, the ends of heavily infested stems droop under the weight of the insects and appear wilted as a result of their feeding activity. Prune off affected stems after the insects have had their fill.

Hibiscus Beetle
Hibiscus beetles have always been notoriously difficult to control because of their hard outer shell and tendency to shelter out of reach within flower petals.  The beetles cause flowers to fall from plants prematurely. Cultivars with white or pale coloured flowers tend to be more attractive to hibiscus beetles. 

Gardeners have several strategies to reduce beetle populations. Picking up fallen blooms each day reduces beetle numbers significantly. Placing white or yellow icecream containers filled with water and a liquid liquid soap beneath plants can trap a significant number of adults. Traps should be emptied every few days and refilled with fresh water and soap.

Ladybird (Twentyeight Spotted)
We have all grown up believing that ladybirds are beneficial insects and most of the over 300 different species of these insects are welcome in our gardens. Unfortunately, there are a few species that feed on the leaves of plants. Telling a good ladybird from a bad one is a matter of counting the spots. Ladybirds with a few spots are likely to be beneficial as both adults and their young larvae feed voraciously on pests such as aphids, scale and mites. Ladybirds with lots of black spots (24-28) on a yellow/brown body (pictured) are leaf eaters commonly known as twentyeight spotted ladybirds.

These ladybirds are common pests of solanaceous plants such as potatoes and eggplants, but also attack pumpkins, rockmelons and other vegetable crops. They also feed on weeds and often migrate from weedy areas of the garden to vegetable or ornamental plants. If twentyeight spotted ladybirds reach plague proportions, remove any weeds that might harbour them, remove as many ladybirds as possible by hand and/or spray with a soap spray.

Leaf Miner
Citrus leaf miner (Phyllocnistis citrella) is the larvae of an introduced moth. The female moth lays her eggs and the larvae quickly burrow between the upper and lower leaf surface of young foliage. The foliage becomes twisted and puckered as the larvae mines and eats its way through the leaf. Heavy infestations disfigure trees and can retard growth, particularly on young trees.

On small trees or those in containers, simply squeezing leaves between your thumb and forefinger can kill the larvae within the leaf. Pruning off affected leaves is another alternative. Female moths avoid leaves sprayed with plant based horticultural oil. Spraying should coincide with new growth flushes. Mandarin trees and Meyer lemons are particularly prone to citrus leaf miner.

Longicorn Beetles
These intriguing lines indicate native longicorn beetles have been hard at work. Longicorns are easily distinguished by their rectangular body shape and enormous recurved antennae. The female beetle removes the outermost section of tissue, ringbarking pencil-thick sections of stem with remarkable precision. She then lays her eggs just beneath the bark in the area immediately beyond the ring. The tree continues to transport water and dissolved minerals from the root system to the foliage via undamaged water conducting tissue located on the inside of the stem. Sugars produced by the foliage are sent down to the roots, but are interrupted by the tissue damage at the point where the eggs are laid. This provides an abundant food supply for the developing longicorn larvae. Affected trees attempt to repair the damage by producing callous tissue to close the ring-barked gap, but the affected stem section usually dies. The longicorn larvae have had their fill by the time this occurs. To control infestations, prune dead stem sections back to a growing point.

Mites
Mites are microscopic plant pests that are more closely related to spiders and ticks than insects. Symptoms of infestation are varied and include loss of leaf colour, drying and cupping of foliage, grey or rusty foliage, fruit discolouration, distorted growth and rind hardening on citrus.

There are many different species of mites. Some common types include broad mite, red spider or two spotted mite (pictured), erinose mite (attack hibiscus and lychee), camellia tea mite (see above), citrus russett mite previously called Maori mite (pictured), bulb mite (attack a range of bulb species), citrus bud mite (pictured) and tomato russett mite.

Dry conditions often increase the incidence and severity of mite infestations, particularly red spider mites. Fine webbing can often be seen where plants with serious infestations.

Palms keep indoors and a range of other indoor or patio plant species are particularly subject to red spider mite infestation. Water plants outdoors each week, taking care to spray the hose up underneath the foliage as this is where mites hide and feed. This will help to dislodge them and keep plants free of serious infestation. Wiping both sides of the leaves with a soft cloth dipped in warm, soapy water can also help.

Lemons and navel oranges seem particularly prone to mites. Spraying plant based oil sprays will suffocate mites. Soap sprays or wettable sulphur kills mites through dehydration. Be alert for the symptoms of mite attack and apply sprays as soon as the condition becomes obvious.

Sawfly Larvae
The larvae of the sawfly are very ugly grubs. They congregate on the foliage of native plants, skeletonizing the leaves as they eat their fill. When disturbed they writhe up at you and spit a caustic substance in your direction. These insects are so hideous that birds do not even seem interested in eating them. I tried feeding them to my chickens once, but even they were not interested.

Fortunately, the native species they attack seem to be able to cope with the defoliation that accompanies an infestation of sawfly larvae, so control is not necessary.

Scale
Several scale species including hard wax scale (Ceroplastes sinensis), white wax scale (Ceroplastes destructor) and pink wax scale (Ceroplastes rubens), black scale (Saisettia oleae) and soft brown scale (Coccus hesperidum) are commonly found on established citrus trees but also affect ornamentals such as gardenias, lillypilly hedges and rainforest trees. Scale insects are commonly associated with ants who harvest honey dew exudate produced by the scale and sooty mould fungus that grows on the honey dew. Oil sprays will control scale and sooty mould. You will need to apply two to three applications at monthly intervals. This will control new generations of scale that emerge from beneath the body of mature scale killed by initial applications. See White Rose Scale below. 

Snails and Slugs
Everyone seems to have a home made remedy to control snails and slugs. Saucers of beer are supposed to attract them, but in my experience the beer must be home made for it to hold much appeal. Non-toxic iron-based baits are the safest of the snail and slug pellet commercially available. Thin copper bands sold through some nursery outlets and mail order companies make effective barriers. Simply place the copper around the edge of the garden bed, fixing it to timber edging or brickwork. As snails and slugs attempt to pass over the copper barrier they receive an electrical shock that repels them (for iron and copper products see Green Harvest on the [Links] page). Poor the leftovers from your coffee plunger over areas where snails and slugs congregate. They hate caffine!.

Spined Citrus Bug
These insects look like they are wearing pointed shoulder pads. When young they vary in colour, but adults are leaf green and well camouflaged. They feed by piecing the fruit of a variety of citrus and sucking up the liquid contents.  Fruit develops dry patches and premature fruit fall is common.  Lemons and mandarins appear particularly susceptible. Wear gloves and pick them off by hand or use a leaf blower or vacuum clearer to suck them up. Oil spray can be effective, but needs to be applied directly to the insect. You need to control these pests as even a small infestation can do considerable damage to your harvest.

White Rose Scale
Infestations of white rose scale can be particularly debilitating to rose plants, eventually killing plants completely if left unchecked. Where infestations are particularly heavy, warm soapy water and a soft scrubbing brush can be used to remove the majority of the scale. A follow up application of an oil based spray, see [Do It Yourself Controls - Oil Spray] will usually bring about control. Repeat as often as necessary. Remember to fertilise affected roses to compensate for the loss of vigour that will undoubtedly result from the scale infestation. White rose scale often multiplies rapidly during winter.

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