Pest-Control Quick-Guide

Do you have a pest in your food garden, but you are not sure what it is, or you don't know what to do about it? Here is to-the-point info and photos that give you the answers!

There are many insects, gastropods and fungi in Tasmanian food gardens. Therefore this blog post will be a work in progress for some considerable amount of time. Initially the more common pests will be covered. Then more pests will be added as time permits.

Weeds can of course be food garden pests too, but this blog post does not cover how to get rid of weeds.

Recommended treatments - suggestions below are always in order of their effect on the environment, lowest impact first. It is suggested that you choose a no-impact or low-impact method, see what the effect is, and then move to a method further down the list if no progress is made and further action is needed.

Toxicity - commercially available pesticides that are known to be highly-toxic to either people or animals or beneficial insects or our soil are not covered in this blog post because they defeat one of the reasons for growing our own, that is to minimise harm the environment and not harm those who eat our produce. For this reason products like Yates Success and insecticides that use Pyrethrum or Pyrethroids are not suggested as control measures.

Biological control methods - use bugs to catch other bugs and are totally non-toxic and very effective. They are becoming very popular in agriculture, and they are great for the environment. Where available, they are mentioned in this blog post, but because their price for home gardeners is still relatively high, they are mentioned down the list of control methods. FGG members could jointly share the purchase of a bunch of bugs to lower the costs per person. www.goodbugs.org.au is an excellent web site by the Association of Beneficial Anthropod Producers. It lists all the beneficial insects that are commercially available in Australia and New Zealand.

Per today this Quick Guide covers Aphids, Brown Rot, Cabbage White Butterfly, Caterpillars, Coddling Moths, Curly Leaf, Downy Mildew, Earwigs, Gummosis, Leaf Miners, Pear and Cherry Slugs, Pearleaf Blister Mites, Powdery Mildew, Rust, Scale, Slaters, Slugs, Snails and Whiteflies

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In alphabetical order .....

Aphids - what are they?

Aphids are small sap-sucking insects that arrive on the wind and love sheltered places where plants are close together. There are over 150 species of aphid in Australia, mostly introduced, which explains why they mostly visit non-native plants. Some aphid species are winged. Others are wingless. Some are black. Some are green. Some are covered in a white waxy substance which makes them look white and woolly. Many varieties feed on just one plant species (onion varieties or legumes or ..), so aphids on your broad beans will not migrate to your onions. Warm humid weather will see them thrive. 

Aphids - how do you control them?

• Transfer ladybirds from somewhere else to aphid-affected plants. They will eat them. Or better, observe for a few days, and ladybirds may simply arrive and have a feast.
• If there aren't many aphids, use your fingers and squash them.
• Prune plants to improve ventilation.
• If plants can cope with a strong water jet, blast them with water to remove the aphids.
• Exclude them from your young broccoli or cauliflower head by covering these with an old stocking before the aphids find them. The stocking will stretch as the flowerhead grows. 
• Use a soapy water spray. Spray the insects themselves (ie. not the plants they sit on) once a day for many days with water + dishwashing liquid.
• Catch aphids that fly on a sheet of yellow material with a sticky coating (for sale in hardware stores). This trap will also catch other insects including beneficial ones.
• Use garlic spray. For a recipe see here.
• Use White Oil (=Horticultural Oil). For a recipe see here.
• Use Neem Oil, an organic commercial product. For more info about Neem Oil see here.
• Buy insects that eat aphids from Bugs for Bugs. For more info see here and here.

  

Excess fluid that aphids collect is secreted. It is called honeydew. Honeydew encourages the growth of the black fungal sooty mould. Where there are aphids, ants are often not far away. The ants feed on the honeydew, and in return protect the aphids from predators.

 

If you get rid of the ants, the aphids are open to attack by predators and may gradually disappear. Because the ants protect the aphids from predators, an alternative approach might be to get rid of the ants, and then the aphids gradually disappear as a result. 

• Ant nests are often near the base of the affected tree or bush. Get rid of the ants by applying home-made Baking Soda & Sugar. For the recipe see here. 
• Alternatively, put a collar with sticky vaseline around the trunk of the tree (replenish regularly)

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Brown Rot - what is it?

Brown Rot is a fungal disease that affects blossoms, leaves and fruit of stone fruit trees (apricot, peach, nectarine, plum, prune and cherry). It usually occurs after wet humid weather. It thrives in spots where air circulation is restricted. Australia's best stone fruit is grown on trees with good ventilation in warm dry areas. Irrigation in those areas is done at ground level. Here are the visible signs of Brown Rot:

• Brown, wilted blossoms 
• Dark, sunken spots on new wood and brown, hanging leaves on infected limbs
• Small spots of rot on affected fruits that quickly grow in size - see first photo below
• Fuzzy grey spores that cover the fruit surface
• Fruit that has shrivelled and hardened (‘mummies’) - see second photo below

Brown Rot - how do you control it?

Control by prevention is the name of the game here. Once a tree has it, it is not easy to stop.

• Prune stone fruit trees in Autumn before they go dormant with the aim to improve ventilation in following seasons, so it will be less likely that Brown Rot occurs.
• In early Spring before blossoms burst spray with Bordeaux or Burgundy mixes a number of times. This makes for a good start to controlling Brown Rot for the season. For more info about these sprays see here.
• During blossoming remove brown, wilted blossoms as soon as you see them, and remove them from your garden. 
• At any time cut away dark infected new wood, and brown hanging leaves.
• Thin fruits (in some cases drastically), so there is some air between them.
• Always remove fallen fruits, and remove them from your garden.
• Skins of plums and cherries my split after summer rains. Remove them, so Brown Rot does not enter these splits.
• Remove mummified fruit as soon as you see it, and  remove them from your garden.
• Some people recommend that you spray with Bordeaux or Burgundy mixes when Brown Rot occurs. However, leaves may well get burned and the tree may suffer. 
• There are commercial chemicals that will control Brown Rot, but they are not recommended if you want to grow organically.

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Cabbage White Butterfly - what are they?

Cabbage White Butterfly are the most common butterfly in Tasmanian gardens (see photo below). Cabbage White Butterfly lay eggs on vegetables that they know their offspring will like most: cabbage, cauliflower, broccoli (members of the Brassica family) and other plants with soft green foliage, especially young seedlings. It is not the Cabbage White Butterfly that is the food garden pest, it is their caterpillar offspring.

Cabbage White Butterfly - how do you control them?

Cabbage White Butterfly are best controlled by 'exclusion', ie. by keeping them away from the vegetables they lay eggs on. Put wire waste baskets over individual seedlings, or put a cage with fine netting over a whole collection of seedlings. Controlling their offspring is a different ballgame all together: see Caterpillars below.

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Caterpillars - what are they?

Caterpillars are the larval stage of butterflies and moths. Caterpillars are a very hungry pest that can completely ruin cabbage, cauliflower, broccoli and other food plants, especially young seedlings. Caterpillars emerge from eggs laid by moths and butterflies on the bottom side of the leaves of plants they know their offspring will want to eat.

Caterpillars - how do you control them?

• Have flowers in or around your food garden. This attracts birds that will eat caterpillars!

• Remove old Brassica plants if they are no longer needed, because they may harbour caterpillars that produce butterflies and moths, that will infect your new Brassicas later in the season.

• Prevent moths and butterflies laying eggs by keeping them away from plants. This strategy is called 'exclusion'. Net your vegetables, or put them in a cage, or put wire waste baskets over them.

• Look for caterpillars and eggs on the under-side of leaves. Squash these with your fingers or feed them to your chooks.

• Commonly known in Australia under the brand-label Dipel, Bacillus thuringiensis (also know as Bt) is a biological insecticide that is ingested by caterpillars when they eat leaves. It is a stomach poison. Caterpillars stop eating soon after and die within a few days. Bt is a narrow-spectrum insecticide: it kills caterpillars, and nothing else. Add a few drops of dishwashing liquid to the mix to make it stick better. Re-apply after rain or overhead irrigation, unless you spray it on the underside of leaves (by inverting your spray nozzle), because then it will not be so easily washed off. 

• Use with a garlic spray. For a recipe see here.

• Use Neem Oil, an organic commercial product. For more info about Neem Oil see here. 

• There are insects that are the natural enemies of caterpillars. You can buy insects that eat caterpillars from Bugs for Bugs here.

 

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Cherry Slugs - what are they?

The small black slugs found on cherry trees are larvae of the Caliroa cerasi black sawfly. Their common name is Pear and Cherry Slug, so please see below under Pear and Cherry Slugs.

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Coddling moths - what are they

Coddling moths are small brown moths. They themselves don't do any damage. Their caterpillar-offspring tunnel through and eat apples, pears, nashi pears, crab apples and quince trees (sporadically also on walnuts and stone fruits). 

Coddling Moths begin to lay tiny eggs on leaves in September and on fruit when it has formed. The eggs hatch into caterpillars that enter a fruit and eat the fruit for 3-5 weeks. They then leave the fruit in search for a suitable place to spin a cocoon. This is often under loose bark around the base of the tree or in the ground. After hatching into a moth, females fly around at night, mating with males, then they lay their eggs on a leaf or fruit, and the whole cycle continues. There are usually 2 or 3 cycles per growing season.

Coddling Moths - how do you control them?

• Remove loose bark and inspect crevices where cocoons might reside
• Don't leave prunings and dead branches under the tree
• Always remove all fallen fruit
• Regularly look for small brown holes in fruit and remove fruit with holes from your garden

• Hang a moth trap in your tree - a plastic container with holes in it containing a sweet liquid. There are many sweet liquids you can use: water with sugar or molasses, apple juice, port.

• Wrap a band around the base of the tree made out of corrugated cardboard or hessian. Fix it with packing tape, string or a staple. The band is an ideal spot for the grub to pupate. The grubs spin their cocoons and can be destroyed before they turn into moths. Check every three weeks or so and remove cocoons from your garden. Apply for the whole of the growing season.

• Use White Oil (= Horticultural Oil). For a recipe see here.

• Horticultural glue - this ensnares the moth as it crawls up the trunk after hatching. Apply some masking tape or similar around the trunk below the corrugated cardboard, and cover in glue. This will also form a barrier for the descending grubs forcing them to pupate in the cardboard. Replace every 3 weeks.

• Use Neem Oil. It is an organic commercial product. More info about Neem Oil see here.

• Hang a pheromone trap (photo below) in the tree to attract the male moth - replace every 3-4 weeks. More about these traps in the blog post mentioned below. 

This is only a summary of what can be done against Coddling Moth. For more detailed info and photos see Food Garden Group blog post Outsmarting the Codling Moth.

 

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Curly Leaf - what is it?

Curly leaf (officially peach leaf curl - Taphrina deformans) is a fungal disease of peaches, almonds and nectarines, which causes severely distorted leaves and sometimes fruits. Curly Leaf can weaken a fruit tree to the extent that it drops most leaves and all fruit that season.

Curly Leaf - how do you control it?

In Tasmania Curly Leaf is so common that it is best to assume that your tree will get it if you don’t spray it. Adopt the following strategy:

• While trees are dormant: remove all last season's leaves, left-over fruit and loose bark from the tree and under the tree. Prune to improve air circulation.

• While trees are dormant: in Tasmania in most years fruit trees are dormant from the start of June until the middle of August. During this period spray the tree with a copper-based fungicide. This can be Bordeaux Mix, Burgundy Mix (for recipes see Homemade Pest Control Sprays on this blog) or a ready-to-use commercial copper spray. Spray the whole tree and the ground under it twice with a fortnight interval. Do this before blossoms and leaves open.

• During the season: if leaves are affected by Curly Leaf spraying will have no effect at all. Remove all affected leaves, even if that results in a tree with very few leaves. In most cases the tree will survive and form new unaffected leaves within a short period of time. However, the tree may have been weakened by this event, and as a result fruits may fall off or shrivel up.

For more info see blog post Controlling Curly Leaf on this blog.

 

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Downy Mildew - What is it?

Downy Mildew is not as common in Tasmania as its relative, Powdery Mildew. Symptoms include large, angular or blocky yellow areas on the upper surface of leaves. See the photos below. The underside of infected leaves often appears water-soaked. When looked at closely, a grey-brown/purple-brown mould becomes apparent. Downy Mildew attacks the leaves of grapes, cucumbers, brassicas, lettuce, onion and beetroot.

Mildew is not toxic to humans, but fungi cause allergic reactions in some people, so it is best to discard produce that is affected by Mildew rather than washing and then eating it.

Downy Mildew - how do you control it?

• Spraying grapevines with Bordeaux or Burgundy mix as a preventive measure can be successful. For recipes see here
• Don't grow cool-weather vegetables in mid-summer
• Use varieties that have resistance to Downy Mildew. 
• Provide good ventilation around your plants
• Don't water in the evening 
• Water plants from below
• Cut off mildew-affected leaves when you see the first affected leaves
• Spray with a milk spray. For a recipe see here
• Spray with Bicarbonate of Soda. For a recipe see here
• Spray with a Garlic spray. For a recipe see here

For more info about each of these dot points see blog post Preventing and Overcoming Mildew .

 

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Earwigs - what are they?

The European Earwig (see photos below) is an omnivore that, depending on the situation in your garden and what you grow, can be a pest or beneficial, because it eats caterpillars, insect eggs, mites, arthropods, lice, flies, aphids and other insects, but also takes small cup-sized bites out of soft young foliage, flowers, young seedlings, and ripe berries and fruits. 

Earwigs do not themselves transfer Brown Rot to fruit, but their bite marks make fruit more susceptible to Brown Rot when there is rain or when the weather is humid.

Earwigs love cool moist weather. They are mostly nocturnal, and during the day often hide in small, moist places. That can be underground, where they also lay their eggs. Earwigs are preyed upon by birds, wasps, lizards, centipedes and spiders.

Earwigs - how do you control them?

• General garden hygiene, ie. removing of debris and excessive mulch, will mean fewer hiding spots for Earwigs.
• Chooks will love to help you getting rid of Earwigs. Just make sure they do not eat your food crops as well.
• Trap Earwigs in an upside down pot stuffed with wet newspaper or straw. Alternatively, placeing rolls of damp newspaper, hessian or deep pile carpet (with the pile on the inside) on the ground or around the trunk of trees. Inspect the traps daily and dispose.
• Beer traps (see photo under Slugs) will also be effective. If you want to catch Earwigs linseed oil can be used instead of beer.
• To keep Earwigs away from plants and trees apply non-toxic Diatomaceous Earth around their base. It kills insects by scoring their outer layer as they crawl over the fine powder.
• Earwigs seldom fly, so a sticky band around the trunks of trees, shrubs, and woody plants will prevent them from reaching the leaves and fruits on which they wish to feed.
• Contact sprays such as garlic spray, chilli spray, insecticidal soap and white oil (see FGG blog post Homemade Pest Control Sprays) will kill Earwigs if you hit them directly.
• One species of Tachinid fly (Triarthria setipennis) has been demonstrated to be successful as a biological control of earwigs for almost a century.

  

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Gummosis - what is it?

Gummosis is the oozing of sap from wounds on fruit trees such as apricot, cherry, peach and plum. Cytospora canker is the fungal cause of Gummosis. Gummosis is the result of either an injury (inflcted with a garden tool) or environmental stress (lack of water, lack of nutrients, or too much water and cold weather). 

The Cytospora fungus kills the wood underneath the wound. Symptoms of Gummosis are gum, defoliation and dieback. Gummosis weakens the tree. If the disease infects the trunk, the whole tree may die. A tree may recover over time if you follow the suggestions below.

Gummosis - how do you control it?

If the tree is not badly affected, you may be able to limit the impact of Gummosis by pruning away the (parts of) branches that are affected, then making sure your tree is not stressed by looking after it as best as you can - mulch it, water it sufficiently (but do not over-water it) and feed it Complete Organic Fertiliser or similar. Do not do this while the tree is dormant.

There is no known chemical remedy for Gummosis. As a last resort remove darkened areas of bark plus a strip of the healthy bark around it until the wound is surrounded by a margin of healthy bark. Then paint the wound with copper-based fungicide. Keep checking the area and repeat the bark trimming if necessary. I did this with a severely affected peach tree near the end of the season. The following season the Gummosis did not return! 

 

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Leaf Miners - what are they?

Leaf miners are small greyish black flies about 2 mm long. It is not the flies that do the damage, their larvae do. They 'mine' their way through leaves while feeding. Feeding causes loss of healthy leaf tissue, so the plant can’t capture sunlight in the affected part of the leaf. Severely affected plants may fail to grow.

Leaf Miners - how do you control them?

• Pick off and destroy badly infested leaves 
• Maintain plant health with organic fertilisers and proper watering, so plants outgrow the damage.
• Use Neem Oil, an organic commercial product. For more info about Neem Oil see here. 
• Use White Oil (=Horticultural Oil). For a recipe see here.

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Mildew - what is it?

For more info about Mildew see Powdery Mildew and Downy Mildew.

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Pear and Cherry Slugs - what are they?

Pear and Cherry Slugs may look like slugs (photo on the left below), but they are not actually members of the slug family. They are the larvae of Caliroa cerasi, also known as Black Sawfly. Black Sawfly larvae eat the soft tissue of leaves of pear, cherry, plum, apple and quince trees, leaving just brown leaf skeletons when finished (photo below on the right).

Pear and Cherry Slugs - how do you control them?

Containment period 1 - when the tree is dormant

• Put chooks, geese or other soil foragers around your tree to catch all overwintering Sawfly pupae. They will do a great job.
• Over a layer of pelletised chook manure spread thick, overlapping layers of newsprint, extending from the trunk to well beyond the drip line, wetting and weighing the paper down with more fertilisers. This is covered with a thick straw mulch so this dense combination acts as a very tight, impenetrable barrier, preventing the emergence of young sawflies.

Containment period 2 - when the tree has leaves

Apply these strategies from the moment you first spot the slugs until the end of the season:

• If there are only a few, remove them by hand - do this two/three times a week. 
• Alternatively, hose the larvae off the tree with a strong jet of water - two/three times a week
• Alternatively, wet all the leaves and then cover them with fine ash from a wood heater or powdered lime. Limil is lime that has been made soluble in water.  It can be bought at nurseries and hardware stores.  Mix half a cup of limil in half a bucket of water, and spray it onto your tree with a sprayer.  Make sure the limil is mixed in well to prevent your sprayer from clogging up. This method is described in more detail in Controlling Pear and Cherry Slugs on this blog.

• Organic pest control substance Bacillus thuringiensis (traded under various names e.g. Dipel) is very effective against Pear and Cherry Slugs and completely non-toxic.

For a full description of this pest and what to do about it see Controlling Pear and Cherry Slugs on the Food Garden Group blog.

 

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Pearleaf Blister Mites - what are they? 

Pearleaf mites are tiny mites that overwinter beneath the scales of fruit and leaf buds. They feed throughout winter and cause infested buds to drop. When buds remain viable and open in the spring, the mites feed on leaves and around blossoms. Several generations develop within blisters during a growing season. Fruit damage is caused by injury to buds. Although with magnification these tiny mites can be observed wandering across plant surfaces, they mostly occur hidden within buds and blistered tissue on the underside of leaves.

Pearleaf Blister Mites - how do you control them?

• Prune the affected tree so its height is manageable, and destroy the pruning (burn or remove)
• In autumn as leaves fall (this is after harvest) apply lime sulphur. You need 'wettable sulphur' (a product that can be sprayed in a mix with water). A spray made by mixing one part lime sulphur with 12 parts water should clear up the problem.
• In late winter before buds open, apply the same sulphur again.
• There is no effective way of controlling this pest at other times of the year.
  
• When the infestation has been reduced one treatment per year should suffice.

 

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Powdery Mildew - what is it?

Powdery mildew is a powdery-like coating of fungal spores that forms on both upper and under sides of leaves on vegetables, berries and fruit trees. The powdery coating is often white, but it can also be yellow or black. Once it has taken hold it can continue to grow, even in dry conditions. Often a plant's vigour, flowers and fruits may be seriously affected. Leaves can distort, and fruit may fall off or not fully develop. 

If the weather is warm and humid for a few days, and it remains humid at night, mildew that arrived in your garden via wind, windswept rain, a bee, an aphid, or a bird may get a foothold, no matter what you do.

There are many species of Powdery Mildew fungi and most of them are specific to either one host species or a narrow range of closely related hosts. In other words, Powdery Mildew on your peas might spread to your beans, but it will not affect your tomatoes and vice versa.

Peas and beans on affected plants are perfectly edible. Well established carrots and parsnips will produce, even if affected by Powdery Mildew.

Mildew is not toxic to humans, but fungi cause allergic reactions in some people, so it is best to discard produce that is affected by Mildew rather than washing and then eating it.

Powdery Mildew  - how do you control it?

• Grow cool-weather vegetables when in Spring or Autumn, not in Summer.
• Powdery Mildew may manifest in new leaves on young shoots in apple trees in early Spring. If so, cut off all infected shoots and remove the debris from your garden.
• Use varieties that have resistance to Powdery Mildew. 
• Provide good ventilation around your plants
• Don't water in the evening 
• Water plants from below
• Cut off mildew-affected leaves
• Spray with a milk spray. For a recipe see here
• Spray Bicarbonate of Soda. For a recipe see here
• Spray with a garlic spray. For a recipe see here

For more info about each of these dot points see blog post Preventing and Overcoming Mildew .

 

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Rust - what is it?

Rust is a fungus that manifests itself as rust-brown speckles on leaves and stems of plants. Rusts - plural, because there are thousands of varieties - are pathogens of order Pucciniales that are highly specialised and infect only very particular plant hosts. Rust on garlic, for instance, will not affect plants in your garden that are not part of the Allium family. Rust spores may arrive by wind, via water, insects or live plant material.

Rust - how do you control it?

• Always check seedling and plants for Rust before adding them to your garden
• Wash tools after working with plants that are affected with Rust
• Plant and sow plants so there is space between them when the plants are mature
• Irrigate from below rather than above
• Plant and sow in well-draining soil
• Remove fallen leaves, especially from affected plants
• Rotate your crops
• Remove affected leaves as soon as you see them and remove them from your garden
• Ask yourself whether action is needed as your crop may not really be affected
• Apply Baking Soda & Sugar or Bicarbonate of Soda. For recipes see here .
• Apply Bordeaux Mix or Burgundy Mix. For recipes see here .
• Apply White Oil twice, a week to ten days apart. For a recipe see here.
• Use Neem Oil, an organic commercial product. More info about this here.

For more detailed info and more photos see When Rust blows in on this blog.

 

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Scale - what are they?

Scale are insects that pierce plant tissue and, remaining in the place that they have chosen for the rest of their lifetime, feed on sap. They attach themselves to stems, leaves and sometimes fruit and can weaken a tree. Most varieties of Scale have a hard shell and quite firmly attach themselves to their chosen spot. That means that they can be a bit tricky to get rid of. Scale is most commonly found on citrus trees. Apple trees can also be affected. Some Scale species have a woolly appearance, but should not be confused for Woolly Aphids.

Excess fluid that Scale secret is often called 'honeydew' because it is sweet. Where there is Scale, ants are often not far away. The ants feed on the honeydew, and in return protect the scale from predators. Sooty mould is scale droppings that have turned black and mouldy.

Scale - how do you control them?

• If scale is only just beginning to establish itself, simply squash them with a finger. 
• Remove affected leaves or branches, if the infestation is not all over the plant. Put those off-cuts in the bin, not your compost heap.
• To help the tree or bush gain the upper-hand give it a lot of water with liquid fertiliser, a number of times.
• Use water, soap and an old toothbrush. Dip the toothbrush in the water, rub it against the soap, and then scrub the scale off the branches.
• Use and old toothbrush and apply undiluted methylated spirits straight from the bottle.
• Apply White Oil twice, a week to ten days apart. For a recipe see here.
• Use Neem Oil, an organic commercial product. More info about this here.
• Buy insects that are the natural enemies of Scale. More info about this here.

If you get rid of the ants, the scale are open to attack by predators and may gradually disappear. The sooty mould is then gradually washed off by the rain.  

• Ant nests are often near the base of an affected tree or bush. Get rid of the ants by applying home-made Baking Soda & Sugar. For the recipe see here. 
• Alternatively, put a collar with sticky vaseline around the trunk of the tree (replenish regularly)

Scale with their friends the ants

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Slaters - what are they?

Slaters are little grey bugs found under logs, pots, rocks, bricks, leaves, compost and mulch. They might be called slaters because they have the colour of slate. Slaters are great for your garden as they eat organic matter and return nutrients to the soil. Having a few slaters around will keep your plants happy and healthy. Slaters need moisture and mostly come out at night when the risk of drying out is low. Slaters are also known as Pillbugs or Wood Lice. 

Slaters - how do you control them?

In most cases Slaters are beneficial for your garden, so you don't want to get rid of them. However, Slaters will occasionally feed on young plants, and that could be a reason to do something about them. Older plants with tougher stems are less attractive to Slaters.

There are some simple things you can do if Slaters are a problem in your garden:

• If they are taking over your compost heap, there is nothing to worry about, but if it really worries you, you could disturb your compost by raking it frequently during hot, dry days.
• Chickens or ducks love to eat Slaters, which provide good protein for egg production.
• If Slaters are nibbling your young seedlings, distract them! Put some hollowed out orange halves or seedling punnets filled with potato peelings out in the garden for the Slaters to munch on. Remove these when full, and empty them somewhere away from where the Slater are a problem.
• Keep Slaters away from young seedlings by putting coffee grounds around the seedlings.
• Around plants with low leaves and fruits keep leaves and fruit off the ground, so they are few shady places for Slaters to hide.
• When sowing seed, keep mulch away from where you sow as Slaters won't go far from cover.

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Slugs - what are they? 

Slugs are gastropods that don't have a shell. Slugs feed on a wide variety of vegetables, herbs, flowers and fruits. Slugs hide in sheltered spaces, when it is sunny and hot during the day, and when conditions are dry, or freezing. They are most active at night in wet weather with mild temperatures.

Slugs - how do you control them?

• Go slug-hunting at night: go out with a torch and remove slugs wherever you find them. If you don’t like crushing them, dump the slugs in a bucket with salty water and they die instantly, or collect them and feed them to your chooks.

• Install beer traps for slugs. A bowl with a lid (the rim just above soil level - see photo), is ideal. Very effective. Remove and refresh the beer regularly.

• After dark slugs travel from far and wide to feast on lucerne hay. It is a great way to collect many in one place. Just realise that therefore lucerne hay should only be used on empty beds or around mature plants.

• Create slug-shelters (terracotta pipe, spaces under bricks, or upside-down pots), and collect them during the day.

• Exclusion can be effective. Borders of Diatomaceous earth (for sale at hardware shops) or crushed egg shells or coffee grounds will be avoided by slugs. Refresh after rain.

• Use garlic spray on vegetables you know they are going to visit at night.  For a recipe see here.

• Multiguard Snail & Slug Killer is one of a number of reportedly pet and bird friendly substances that use iron chelate as active ingredient and that are quite effective against slugs and snails.

• Parasitic nematodes are a commercially available biological control method that are effective against slugs.

 

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Snails - what are they?  

Snails are gastropods with a shell. Snails feed on a wide variety of vegetables, herbs, flowers and fruits. Snails hide in sheltered spaces, when it is sunny and hot during the day, and when conditions are dry, or freezing. They are most active at night in wet weather with mild temperatures.

Snails - how do you control them?

• Go snail-hunting at night: go out with a torch and remove slugs wherever you find them. If you don’t like crushing them, dump the snails in a bucket with salty water and they die instantly, or collect them and feed them to your chooks.

• Install beer traps for slugs. A bowl with a lid (the rim just above soil level - see photo above), is ideal. Very effective. Remove and refresh the beer regularly.

• After dark snails travel from far and wide to feast on lucerne hay. It is a great way to collect many in one place. Just realise that therefore lucerne hay should only be used on empty beds or around mature plants.

• Create snail-shelters (a terracotta pipe or space under bricks), and collect them during the day.

• Exclusion can be effective. Borders of Diatomaceous earth (for sale at hardware shops), crushed egg shells, wood ash, or coffee grounds will be avoided by snails. Refresh after rain. Don't use too long in one spot as the soil will become too affected.

• Use garlic or chilli spray on plants they are going to visit at night.  Refresh after rain. Recipe see here.

• Multiguard Snail & Slug Killer is one of a number of reportedly pet and bird friendly substances that use iron chelate as active ingredient and that are quite effective against slugs and snails.

• Parasitic nematodes are a commercially available biological control method that are effective against snails.

 

 

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Whiteflies - what are they?

Whiteflies are tiny white flying insects (photo 1 below) that suck sap from especially the undersides of leaves. Seldom will you see just one whitefly. They often fly away in small swarms when you touch an affected plant. Whiteflies will over time skeletinize leaves and weaken plants, but bean pods or fruits remain unaffected. The sooty mould that grows on their excrement reduces quality of produce and interferes with photosynthesis. Whitefly offspring (nymphs - photo 2 below) are oval shaped and have an appearance similar to soft scale insects.

Whiteflies - how do you control them?

• If you detect whiteflies only a few weeks before picking most of your tomatoes or beans or whatever you are growing, consider doing nothing, because the whiteflies won't affect your crop.
• A non-chemical way of removing whiteflies is to shake plants while having a vacuum-cleaner on and ready and then sucking them up the vacuum-cleaner nozzle as they flutter up. 
• Another no-spray method is to hang yellow sticky glue traps (for sale in hardware stores and nurseries) in your hothouse. The glue is not poisonous. Disadvantage of glue traps is that they will also trap beneficial insects such as bees, so don’t put them in areas where you want bees or know there are bees.
• The sprays listed below are all effective against whiteflies. Spray every three days. They are contact sprays, so spray the whiteflies themselves, not the plants, and don't forget to look for whiteflies and their nymphs on the undersides of leaves. These sprays are all broad spectrum, ie. the will kill not just whiteflies.
• Make your own White Oil (=Horticultural Oil). For a recipe see here.
• Make your own Insecticidal Soap. For a recipe see here.
• Available commercially is organic Neem Oil. For more info about Neem Oil see here. Research undertaken in NZ on Neem's effectiveness for whitefly found that it had a major impact by preventing the nymph-stage from developing into an adult; the nymphs tend to disappear from the treated plants.
• Available commercially is Natrasoap.
• Australian company Bugs for Bugs sells the natural enemies of whiteflies. See here.

           

 

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Woolly Aphids - what are they?

Woolly Aphids don’t look like aphids (see photos below) and don’t move around as much as non-woolly aphids, but are part of the same sap-sucking family of insects that arrive on the wind and love sheltered places where plants are close together. Woolly aphids are covered in a white waxy substance which makes them look white and woolly. Woolly Aphids are controlled the same way as other Aphid varieties.

Woolly Aphids - how do you control them?

• If there aren't many, just squash them with your fingers.
• If the plant has dense foliage prune it to make the environment more open to the elements.
• If plants can cope with a strong water jet, blast them to remove the aphids.
• Transfer ladybirds from somewhere else to aphid-affected plants. They will eat the aphids. If the Woolly Aphids are no immediate threat, just observe. Ladybirds may arrive and have a feast!
• Exclude them from young broccoli or cauliflower heads by covering these with an old stocking before the aphids find them. The stocking will stretch as the flowerhead grows. 
• Spray with soapy water (dishwash liquid). Spray the insects themselves (ie. not the plants they sit on) once a day until the aphids are dead or gone.
• Use garlic spray. For a recipe see here.
• Use White Oil (=Horticultural Oil). For a recipe see here.
• Use Neem Oil, an organic commercial product. For more info about Neem Oil see here.
• Spray with Methylated Spirits once a week until gone
• Catch aphids that fly on a sheet of yellow material with a sticky coating (for sale in hardware stores). This trap will also catch other insects including beneficial ones.
• Buy from Bugs for Bugs insects that eat aphids. For more info see here and here.

 

Photos of Woolly Aphids by Andree Poppleton

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The End  (until I have time to add more pests)

Max Bee