SUCKING INSECTS
If there are insects on the leaves or stems and the leaves do not appear to be chewed, then it is most likely to be leaf sucking insects.
When plants have been attacked by pests, in most cases, providing it is the right time of the season, I would suggest that you give the plants a feed of fertilizer to held restore their vigour.
NOTE:- Always read the directions on the chemical containers before you mix or use the chemical.
******************************
APHIDS
Aphididae
Aphids have a piercing and sucking mouthpart in which they extract the sap from plants.
IDENTIFICATION
When Aphids are present the shoots are distorted, the leaves are curled
and there are shiny secretions on the young soft tissue of the plants. Aphids are soft, fleshy bodied insects with obvious legs .They live in colonies, where they cluster on young shoots and leaves. There are some species which attack hardwood parts of the plants. Aphids come in many colours, white, green , black, brown, woolly etc. There are eight specialized species which are native to Australia and at least ninety eight others which have been introduced. Aphids attack a wide range of plants, both exotic and native, including commercial crops.
Aphids feed by withdrawing the sap from parts of the plants, and excreting a liquid, sweet, sugary substance called honeydew. This substance attracts the ants which feed off it.
(See chewing pests for information on ants)
Ants will attend the colonies protecting them and even relocate them on untouched new shoots. Ants will drive away and destroy parasites which attack the aphids.
Honeydew also provides an excellent substrate for the growth and development of sooty mould. This unsightly black fungus covers the branches and leaves, preventing sunlight from reaching the leaf surface.
Many a car has had the paint surface covered with a thick, sticky substance
which has to be removed by hard scrubbing with soap and water.
SYMPTOMS
Aphids in large colonies will cause wilting of the soft shoots and after a time of constant attack the young leaves will deform and die-back on the tips will begin. Aphids can transmit disease from one plant to another.
CONTROL
Lady Birds (the adults and larvae) are very fond of aphids and are one of the best predators to help in controlling these troublesome pests. Aphids can be squirted off the plants with a hard jet of clean water which drowns some of them, but beware that you don't bruise soft foliage plants or flowers. You may need a chemical spray to kill these pests.
One of the best methods is to spray infested areas with SHARP SHOOTER PYRETHRUM.
If the infestation persists and is very difficult to kill then I would suggest that you use a systemic spray, such as SYSTEX or Folimat.
NOTE. READ ALL DIRECTIONS ON CONTAINER BEFORE USING.
******************************
MEALY BUG
Pseudococcidae
They will attack a wide variety of plants; trees, shrubs, fruit trees, ornamentals, cacti and succulents, indoor plants and ferns.
IDENTIFICATION
These are soft, plump, insects which are closely related to scale.
They exude a dense covering of waxy filaments which acts as a protective
device and repels water. These pests collect in colonies and suck the sap out of soft young plant stems, leaves, shoots and flower buds. Mealy bug prefer to feed under cover, congregating in leaf axils, leaf sheaths and on the underside of the leaves.
Mealy bug feed by withdrawing the sap from the plants, and excreting
a liquid sweet sugary substance called honeydew. This substance attracts the ants which feed off it.
(See chewing pests for information on ants)
Ants will attend the colonies protecting them and even relocate them on untouched new shoots. Ants will drive away and destroy parasites which attack the Mealy bug.
Honeydew also provides an excellent substrate for the growth and development of sooty mould. This unsightly black fungus covers the branches and leaves, preventing sunlight from reaching the leaf surface.
SYMPTOMS
Mealy bug attack a wide range of plants :- Ferns, Gardenias, Indoor Plants, Orchids, Palms etc. With increase in population the plants become distorted and slowly begin to die.
CONTROL
Remove dead leaves and small branches where Mealy bug have collected.
Spray infested areas with a systemic insecticide, such as SYSTEX or Folimat.
MEALY BUG IN THE GROUND
Spraying the plants with a 'systemic chemical' the same way you would for leaf Mealy bug, will have the same controlling effect. As these pests sucked the sap from the roots they consume the poison the same way.
You must note that Mealy bug is one of the hardest pests to eradicate, and it may take quite a while before you get the upper hand.
NOTE. READ ALL DIRECTIONS ON CONTAINER BEFORE USING.
******************************
SCALE
These pests attack a wide range of plants and the masses of ants moving up and the tree gives you a good indication that there may be a scale infestation.
IDENTIFICATION
Scale are extracting insects which conceal themselves underneath waxy, leathery or cottony shells or secretions. They are small, flat, black, brown or white scales that stick on branches, stems and leaves. Scale generally live in colonies and cause growth reduction as well as weakening and distorting the new leaves and shoots.
Scale are soft-body insects which hide under a covering of scale. They feed by their mouth parts which are attached to the plant withdrawing the sap and excreting a liquid sweet sugary substance called honeydew.
This waste product also provides an excellent substrate for the growth and development of sooty mould. The unsightly black fungus covers the branches and leaves, preventing sunlight from reaching the leaf surface. This sticky substance attracts the ants which feed off it.
(See chewing pests for information on ants)
Ants will attend the colonies protecting them and even relocate them on untouched new shoots. Ants will drive away and destroy parasites which attack the scale. They are known to collect the scale eggs and store them during the winter months underground and replace them back onto the plants during the spring. Scale attack a wide range of plants, both exotic and native, including commercial crops.
CONTROL
Remove small infestations from the plants by squashing them or cut off the small branches and burn them. Large infestations should be sprayed with applications of Malathion mixed with WHITE OIL until all the insect pests have been destroyed. Ferns and soft plants should only be sprayed with half to three quarter strength of the recommended dose prescribed on the container. If you are not sure, spray a few leaves and check in a few days if any damage has taken place.
Do not use White oil during the hot summer months as is could cause burning of the plants soft parts.
If the infestation of scale persists and is very difficult to kill then I would suggest that you use a systemic spray, such as SYSTEX or Folimat.
NOTE. READ ALL DIRECTIONS ON CONTAINER BEFORE USING.
******************************
GUM-TREE SCALE
Eriococcus coriaceus
Gum-tree scale are very serious pests of Eucalypts. Severe infestation can cause dieback or even death of trees. Severe infestations cause reduction in growth, weaken the trees and cause malformation of the terminal shoots and premature leaf fall.
Gum-tree scale is a true scale or coccid; the female is anchored on the stem of the plant and the adult male can move about and fly.
Scale are very devastating insects which nourish themselves by sucking the sap from twigs and branches of trees. They will invade all parts of the tree except the main trunk and large branches where the bark is too thick for them to penetrate.
They cluster together in colonies and camouflage themselves beneath leathery coverings.
They feed by their mouth parts which are attached to the plant withdrawing the sap and excreting a liquid sweet sugary substance called honeydew.
This waste product also provides an excellent substrate for the growth and development of sooty mould. The unsightly black fungus (Fumago vagans) covers the branches and leaves, preventing sunlight from reaching the leaf surface. Leaves and branches completely coated with this sooty mould will die as this affects photosynthesis. This sticky substance attracts the ants which feed off it.
(See chewing pests for information on ants)
Ants will attend the colonies protecting them and even relocate them on untouched new branches and shoots. Ants will drive away and destroy parasites which attack the scale. They are known to collect the scale eggs and store them during the winter months underground and replace them back onto the plants during the spring.
Eucalypts with blue-green juvenile foliage, such as the Tasmanian Blue Gum (Eucalyptus globulus), the Shining Gum (Eucalyptu nitens) and the South Australian Blue Gum (Eucalyptus leucoxylon) are favoured hosts for Gum-tree scale.
IDENTIFICATION
These scale resemble round leathery-like globules densely clustered along the branches and stems of the host trees. Squash the Gum tree scale and you will find them to contain a reddish-brown fluid. The scale are thoroughly encased in a thin, durable, white or reddish-brown covering (sac). Small sacs (1-2mm in length) accommodate either an juvenile male (male sacs are white and much smaller and less numerous than those of the adult or immature females and consequently less conspicuous)
They are frequently congregated collectively on leaves or above the females on stems and branches. Immature males under the sacs are flat, elongate, approximately 1mm in length and off-white in colour. Adult males are dark brown and winged. Immature females are similar in appearance to the juvenile males.
The large sacs are reddish-brown in colour (3-4mm in length)which accommodate a single adult female. . The female insect under the sac is a soft body insect, oval in shape, 2-3mm in length and buff to pinky-brown in colour. There is a small circular opening at the tip of the sac through which the young scale (crawlers) emerge. Newly hatched crawlers are about the size of a pinhead. They are pale brown in colour and may be confused for mites crawling over the tree.
Crawlers can be broadcasted long distances by the wind as well on the feet of birds consequently facilitating the scale to spread rapidly.
Immature male and females go through two stages before reaching the adult stage. At the beginning of each stage the insects will leave their old sac and move around for a short time before settling in a new place to feed and secrete a new sac. Adult females are immovable and remain all their lives under the leathery sacs, attached to the plant by their mouthparts. Males appear as winged adults, leaving the white remains of the sac behind on the tree. They have no mouthparts and live for only two or three days.
CONTROL
Once the scale has established itself they can become very difficult to eradicate. Scale are attacked by a wide range of predators and parasites. Predators such as small birds. Remove small infestations from the plants by squashing them or cut off the small branches and burn them
CHEMICAL CONTROL
Large infestations should be sprayed with applications of Malathion mixed with WHITE OIL until all the insect pests have been destroyed. Ferns and soft plants should only be sprayed with half to three quarter strength of the recommended dose prescribed on the container. If you are not sure, spray a few leaves and check in a few days if any damage has taken place.
Do not use White oil during the hot summer months as this could cause burning of the plants soft parts. Care is needed as the oil may damage soft young growth, especially in hot weather. Thus white oil should be used at half strength and be applied only when the air temperature is below 25 deg C. The best time to apply chemicals is when the crawlers are actively searching for a site on which to settle.
If the infestation of scale persists and is very difficult to kill then I would suggest that you use a systemic spray, such as SYSTEX or Folimat.
NOTE. READ ALL DIRECTIONS ON CONTAINER BEFORE USING.
The trees should be given supplementary fertiliser to help restore and encourage vigorous new growth.
******************************
EUGENIA PSYLLID
IDENTIFICATION
Eugenia psyllid develops primarily on SYZYGIUM Paniculatum (Australian brush cherry or Eugenia.) The adults are generally dark brown with a white band around the abdomen. Their tiny golden eggs are laid primarily on the underside of young leaves, causing infested leaf margins to glisten in the sun. Nymphs are yellowish with orange-red eyes. Recently hatched first-instar nymphs (called crawlers) settle on new growth and each forms a feeding pit. Established nymphs resemble a soft scale insect and look flat when examined from the lower leaf surface. 
The upper surface of infested foliage reddens and distorts above these pits. With a severe infestation the new growth tips will twist and wither causing the new growth to look unsightly.
DAMAGE
If the Psyllids are not controlled, the plants in their early stage of developing may experience a large amount of dieback. Eugenia psyllid has about three to about five generations a year, depending on temperature and host plant suitability.
Psyllids suck plant juices. Excessive psyllid populations reduce plant growth or cause terminals to distort, discolour, and can cause defoliation or die back. When psyllid are feeding they cause the plant to form a pit around where each nymph settles. Early damage typically occurs on young foliage where most eggs are laid.
CONTROL
Regular shearing of the new growth will maintain considerable control, by removing psyllid eggs and nymphs. Well-timed pruning in combination with parasite management can be especially effective in managing psyllids infesting Eugenia topiary planting.
When pruning, inspect plants new growth frequently, beginning in spring. Prune growth tips after maximum spring growth appears or about 3 weeks after the first peak of adult psyllid density. This can be detected by using sticky traps and counting and recording the number of adult psyllids on a weekly basis.
No pesticide or other treatment will restore the pitted foliage to a healthy appearance.
CHEMICAL CONTROL
Systemic insecticides are the most practical, effective materials for controlling psyllids which infest large trees. If the infestation of psyllid persists and is very difficult to control, then I would suggest that you use a systemic spray, such as SYSTEX or Folimat.
NOTE. READ ALL DIRECTIONS ON CONTAINER BEFORE USING.
******************************
THRIP
Often thrip are not detected until the damage has been done. This is because they feed under leaves and deep inside flower buds. Early detection before the buds have formed can help save a lot of damage.
Photo on left show damage to Gardenia flower bud by Thrip attack.
A specimen sample like this can help your garden expert identify the problem on your plant.
Make sure you bring your sample in a sealed plastic bag or glass jar.
IDENTIFICATION
There are a number of thrips, some attack dead leaves or old wood and fungi.
The ones we are concerned with are the species that attack our garden.
Some feed on flowers while others take to the leaves. Thrip are often overlooked because of their size and the fact that they tend to feed in protected places such as under leaves or where leaves overlap or deep in the centre of flowers. They congregate in colonies and may all be wingless. Winged adults have slender, knobbed wings with a delicate fringe of hair. Their colours range from yellow, cream, white to brown and black.
Thrip attack a very wide range of plants, ornamentals, fruit trees, annuals, vegetables and weeds. They may also carry plant viruses. The first signs of their presence is the silvery or grey appearance of the leaves. Some thrip cause the leaves to roll up and others cause the plant to produce the characteristic gall. The thrip have asymmetric mouthparts and feed by rasping the surface of the plant tissue which damages the surface of the leaf or flower and they suck the sap as it oozes out. Thrip droppings are large compared to their body size and they show up as little brown tar blotches.
CONTROL
The best way to control thrip before they become a plague, is to spray with a contact material like SHARP SHOOTER PYRETHRUM or Malathion mixed with White Spraying Oil. If these pests persist then I would suggest you use a systemic spray, such as SYSTEX, or Folimat.
NOTE. READ ALL DIRECTIONS ON CONTAINER BEFORE USING.
******************************
WHITE FLY
Aleyrodidae
Each female could lay up to 200 eggs which are usually deposited on the under sides of the leaves of the plants. When they hatch out they suck the sap from the plants causing the leaves to have a fine, yellow mottling look on the upper surface.
IDENTIFICATION
White fly are small sucking insects in the family Aleyrodidae. The adults are winged and are covered in a fine, white powder and when they are disturbed they rise in clouds (this is where their name comes from).
The wingless young flies congregate on the undersides of the developing
leaves extracting the sap. White fly have mainly been a pest to vegetables and glass house plants but other species have now become a problem (ash white fly are very hard to control). They appear in the garden during the warm weather.
SYMPTOMS
The leaves of the affected parts of the plant become like paper and yellow or white in colour. The younger growth tips may begin to wilt and die.
CONTROL
I have found the best time to spray white fly is at dusk when they
are settling down for the night. The way to control white fly before they become a plague, is to spray with a contact material like SHARP SHOOTER PYRETHRUM or MALATHION mixed with White Spraying Oil.
You can also buy a product called Trappit Yellow Sticky Trap. It is a pesticide free, double-sided trap, coated with a hard glue, which is highly effective in catching insects. It does not adhere to hands.
NOTE. READ ALL DIRECTIONS ON CHEMICAL CONTAINERS BEFORE USING.
******************************
Gum-tree scale is a true scale or coccid; the female is anchored on the stem of the plant and the adult male can move about and fly.
The upper surface of infested foliage reddens and distorts above these pits. With a severe infestation the new growth tips will twist and wither causing the new growth to look unsightly.