Annual flowers, SWP & vegetable beds

Cineraria leafminer

Green vegetable bug

Leaf eating ladybirds

Looper caterpillars

Bacterial soft rot

Fungal leaf spots

Sclerotinia

Verticillium wilt

Cineraria leafminer• Order- Diptera• Appearance –The adult is a small grey fly

which inserts it’s eggs into the undersides of leaves. The larvae to 5mm, creamy white. The pupa are barrel shaped, 2.5mm

• Holometabola• Damage- Larvae create “mines” by chewing

inside leaf causing pale grey squiggles, unsightly leaves. Severe infestations retards growth and eventual death of plant. Egg laying causes punctures, leaving scars.

First damage usually appears late winter /spring

• Plants affected-Cineraria, chrysanthemum (Asteraceae plants), nasturtiums, lettuce, sow thistle, capeweed

Leafminer control• Cultural- Remove weeds ( hosts on sow thistle,

capeweed, mist flower)• Physical – Remove leaves, squash miners inside leaf (hold towards light to find active miners), fertilise

and water• Chemical- Spray pest oil to deter (check temp), dust

leaves with ground rock phosphate, Pyrethrum, garlic/onion spray

Or selected systemic in heavy infestation when damage first seen.

Check that larvae have not pupated before spraying

Green vegetable bug • Order- Hemiptera• Appearance –The adult is shield shaped,

green and can be distinguished by the top edge of the triangle on their back: it has a black spot in each corner & 3 yellow spots between them. The larvae have a combination of colour changes at each moult

• Damage- Piercing & sucking, fruits and seeds mainly affected causing shrivelling and distortion. Young shoots can also be damaged

• Plants affected- A wide range of herbaceous plants & weeds including pumpkins, capsicum, potatoes, oranges, peas beans and tomatoes.

Green vegetable bug control• Cultural – Control weeds, remove plants that have

finished bearing• Physical – Hand remove at young nymphal stage• Chemical- Contact –observe withholding period• Biological- An important predator of the GVB is

the parasitic wasp Trissolcus baslais, which parasitise GVB eggs. The parasitised eggs are simple to identify, as they appear black and not the usual orange colour.

Leaf- eating ladybirds• Order- Coleoptera• Appearance – Adults are oval,

6mm, dull yellow orange with 28 spotted, 26 spotted. Larvae yellow-green covered in black, branched spines

• Damage-Larvae feed on lower surfaces& adults appear on upper surfaces leaving a network of veins. Each skeletonised patch is crescent shaped. Fruit can be blemished

• Plants affected- melons, beans, potatoes, etc SOLANACEAE BRASSICACEA

• DO NOT CONFUSE WITH 18 SPOTTED LADYBIRD

• ( BENEFICIAL )

Ladybird control• Physical- hand removal

• Chemical-Spray with Permaguard (ground diatomaceous earth & pyrethrum), glue spray or other poison

• Biological-Birds, assassin bugs, soldier beetles, mantids

Looper caterpillars

Looper caterpillars• Order- Lepidoptera

• Appearance –Larvae arch the middle part of body to form a loop, green-blue, taper to head, thin white lines. Adults are dark brown with silver bronze pattern moths

• Damage-Larvae chew on undersides making ‘windows’. Older larvae chew ragged holes, severe infestations can defoliate & damage fruit

• Plants affected- A wide range of herbaceous plants

Looper control• Biological- Birds, wasps, lacewings, scorpion

flies, dragonflies, Dipel ( bacteria)• Assassin bug ( Pristhesancus) injects an

debilitating enzyme into their prey which dissolves the inner organs which is then sucked out leaving an empty shell- compatible to other biocontrol

• Trichogramma wasp lays her eggs into moth eggs, emerging wasps parasitise other moth eggs

• Physical- hand remove• Chemical- Pepper spray, glue spray, Pyrethrum,

Pest oil or other

Benficial Insects

Green Lacewing

Snails and slugs

• Damage?

• Mouthparts

• Control methods??

Bacterial soft rot• BACTERIA• Symptoms & Damage- Soft,

depressed areas and mushy decay with a very offensive odour. Bacterial slime is often seen on affected areas

No furry growth - is not fungal• Plants affected- Wide host of fruits,

tubers, fleshy roots & succulent buds and stems

• Source of infection- soil & infected plant material

• Control-Do not over water, do not dig tubers or storage organs in wet soil, store in dry conditions. Avoid damage at harvest time

Bacterial soft rot

Decay of wrapper and outer head leaves

Brown spots on the tuber surface will turn into a cream-

coloured rot that rapidly destroys the tuber.

Bacterial soft rot

Decay of core and internal cabbage head tissue

Fungal leaf spots• FUNGUS (various)• Symptoms & Damage- Vary in

shape, size and colour depending on host and fungus. Often have concentric rings with red or yellow coloured borders. Small yellow specks –enlarge- go pale brown-dark brown with yellow halo. Disease starts at base of plant & moves upward. Also causes seedling damping-off

• Plants affected- Wide host of annuals and SWP, high moisture,

• Source of infection- infected plant material, plant debris, over wintering mycelium

Fungal leaf spots• Spread- Free water on leaf surfaces

(esp at night) essential for spore germination. Prefer warm nights >250C) and hot, humid nights. Rain splash, wind, carried on bodies of insects, hands of staff and tools

• Rainy periods favour fungi sporulation and spread to unaffected foliage. Infection may occur at any time, but the disease is usually most severe on new, emerging foliage during spring and autumn rainy periods.

Fungal leaf spots

Cristulariella leaf spot on a Magnolia leaf

Fungal leaf spots• Control- Remove & destroy

infected material, do not water at night water when water may pool on leaves, ensure clean stock, spray with Bordeaux,

• Fungi that cause leaf spots form spores on the leaves. The new spring infections are commonly caused by spores from last autumn leaves. Therefore, rake and destroy last season's leaves before buds break in the spring.

• Prune out over thick growth on deciduous trees and shrubs to allow better air circulation Cristulariella on Maple leaves

Fungal leaf spots

Colletotrichum leaf spot. Left, small and large spotson leaf; right, close-up of leaf lesion with dark specs (acervuli and setae) in center

Fungal leaf spot on iris.

Fungal leaf spots

Sclerotinia• FUNGUS• Symptoms & Damage- Plants may

suddenly wilt, lower leaves turning yellow. Plants often topple over at the point of infection which is usually near ground level. Characteristic symptoms are a brown, soft, wet rot with an associated mass of fluffy white mould which contains large hard dark bodies, called sclerotia.

• worse in cool, wet weather (100-250C).

• Plants affected-Herbaceous plants• Source of infection-Sclerotia in plant debri and soil, infected plants

Sclerotinia

• Spread- wind blown spores from germinating sclerotia More common during Autumn, Winter and Spring. Disease can show up in storage eg. refrigerators which are not cooling properly

SclerotiniaControl• Remove & destroy infected

material, • crop rotation- avoid planting

susceptible crops in affected area for four years-Sclerotia can remain viable in the soil for up to seven years.

• Use resistant plants• Regular cultivation removes

weeds, lowers humidity around plants and destroys germinating sclerotia

• Improve drainage and spacing plants will reduce humidity

Verticillium wilt• FUNGUS

• Symptoms & Damage- The soil inhabiting fungus enters through root hairs, lower leaves are usually first to go and have pink –purple tinge or wilt & dry, become yellow, light brown base of stem

• Plants affected-Wide range

• Source of infection- Infested soil. Mycelium enters roots and blocks xylem tissue

• Spread- wind, water, soil, infested cuttings, tools, cool conditions, waterlogging, high N

                              

Cross-section of a tree trunk. The wood composed of xylem laid down in the form of annual rings.

                  

Verticillium wilt

Verticillium wilt typically causes the margins of leaves to turn brown giving the leaf a scorched appearance.

Wilting and yellowing of leaves

Verticillium wilt

Black raspberry plants wilting from Verticillium wilt.

Maple tree infected with Verticillium wilt

Verticillium wilt

Symptoms of Verticillium Wilt in olive groves

Verticillium wilt

• Control

Remove & destroy infected material, crop rotation, improve drainage, use resistant cvs, control weeds, hygiene, tools, do not propagate from infected plants

Sapwood discoloration in maple twig.