Feature

Crawling critters

Green Lifestyle magazine

In our fight against vegie garden pests, it’s essential to know which are beneficial and which are detrimental. Here’s your guide to the good guys and the bad guys.

Insects-story

Clockwise from top left, the good guys: Praying mantis, Bee, Spider, Lacewing, Ground beetle, Ladybird.

Insects-story2

Clockwise from top left, the good guys: Centipede, Hover Fly, Braconid Wasp, Predatory Bugs, Earthworms, Tachinid Fly.

insects-story3

Clockwise from top left, the bad guys: Catepillar, Leaf-eating Ladybird, Japanese Beetle, Aphid, Scale, Cabbage White Butterly.

insects-story4

Clockwise from top left, the bad guys: Mite, Thrip, Slugs and Snails, Ants, Flies, Fleas and Mosquitoes, Mealybug.

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THE GOOD GUYS

Praying mantis
The only insect able to turn its head and look over its shoulder, praying mantis’ lie in wait for unsuspecting insects before snapping them up in their strong forelegs. They are useful for controlling flies, mosquitoes, caterpillars, aphids and grasshoppers.
Tip: Set any pruned branches with praying mantis egg cases aside in a sheltered spot.

Bees
What would we do without bees? Bees transfer pollen from flower to flower, enabling them to form fruit. There are 1500 species of native bees in Australia, 10 of them stingless.
Tip: Nectar-rich flowering plants will attract bees. Native bees love Angophora and Eucalyptus trees, Brachyscome groundcovers, grevilleas, Leptospermum and Westringia.

Spiders
They may not all be beautiful but learning to love these efficient eight-legged predators will help your garden thrive. Huntsman spiders are among the most beneficial group of spiders; they capture and feast on cockroaches, moths and flies but are harmless to humans.
Tip: Leave spider webs and egg cases alone. Wear gloves while gardening to avoid bites.

Lacewings
Thin and long with lacy wings, the larvae of these insects are more useful than the adults for getting rid of garden pests. Nicknamed ‘aphid lions’, the larvae dine on aphids, small caterpillars and their larvae, mealybugs and whiteflies.
Tip: Plant coriander, dill, dandelion and fennel to attract lacewings.

Ground beetles
When the sun goes down, these carnivorous predators emerge from rocks, logs and underground to hunt insects and their larvae, the pesky cabbageworm in particular. There are thousands of species within the ground beetle family, but most have flattened bodies, long legs for moving fast, and prominent mandibles.
Tip: Clover attracts ground beetles.

Ladybirds
These familiar bugs feast on such garden nasties as mealybugs, aphids and spider mites. Orange or red with black spots, ladybirds live on or under leaves and a single adult can consume more than 5000 aphids during its lifetime.
Tip: Attract ladybirds with plenty of nectar and pollen-producing plants.

Centipedes
Moving with ease through leaf litter and soil, centipedes have one set of legs per body segment (but do not have 100 legs, as commonly thought) and a set of venomous fangs (harmless to humans). They eat snail and slug eggs and insects pupating in the ground such as fruit fly.
Tip: Dark, damp places such as compost bins are heaven for centipedes. Ensure yours doesn’t dry out.

Hover flies
With their yellow-and-black stripes and narrow waists, hover flies are often mistaken for wasps, but these useful little insects are harmless. They devour aphids and pollinate many plants as they hover among flowers looking for food and shade.
Tip: Plant German chamomile and fennel to attract hover flies and let some parsley go to seed.

Braconid wasps
This family of stingless wasps has over 800 species and helps control aphids and tomato hornworms. They grow up to 2 cm long and lay their eggs in or on other insects. When they hatch, the host insects are then devoured.
Tip: Plant marigolds, daisies, lemon balm, dill and coriander to attract them.

Predatory bugs
The appropriately named minute pirate bugs, ambush bugs and assassin bugs prey on many insects our gardens could do without, such as spider mites, tomato hornworms, scales and leafhoppers. Thrips are a favourite morsel in the spring.
Tip: Fennel, spearmint, goldenrod, caraway and alfalfa all attract predatory bugs.

Earthworms
Worms not only aerate and nourish your soil when they turn dead plant matter into nutrient-rich worm castings, they also attract birds that can further help keep pests at bay.
Tip: Keep garden soil moist and mulched. Consider starting a worm farm (which use red worm or tiger worm species) that makes use of your kitchen scraps.

Tachinid flies
They may be small, but these useful flies control a host of garden pests: loopers, armyworms and grasshoppers to name a few. Tachinid flies lay their eggs close to or on a host caterpillar, and hatched larvae then burrow in and eat their hosts from the inside out.
Tip: Plant golden marguerite, buckwheat and lemon balm to attract them.

THE BAD GUYS

Caterpillars
Caterpillars are the larvae of moths and butterflies, and have voracious appetites – they can defoliate an entire tomato plant in just a few days. Some, such as looper caterpillars, feed under leaves and lie along stems so can be hard to spot and control.
Tip: Herbs such as rosemary, mint, dill and thyme all repel caterpillars.

Leaf-eating ladybirds
These troublesome ladybirds attack water-stressed plants. Their eggs are laid underneath leaves so the larvae can happily feed on them without detection. Leaf-eating ladybirds can be distinguished by their spots: they have 26 or 28 compared with the garden friendly variety, which have less.
Tip: Squash adults and scrape their eggs from leaves.

Japanese beetles
These green-headed beetles aren’t fussy about what they eat and will leave behind the skeletons of leaves and not much else. To make matters worse, they send out pheromones to signal others to feeding sites, and gather in large numbers.
Tip: In the early morning, shake beetles off the plant into a bucket of soapy water. Deter with white geraniums and garlic.

Aphids
Aphids are so small that if you do manage to spot them, the damage has probably already been done. These pear-shaped bugs suck plant leaves dry until the leaves curl up and fall off, and can also spread plant diseases.
Tip: Mix warm water with garlic and powdered cayenne pepper. Leave in the sun for a few days, strain and spray onto affected leaves.

Scale
These sapsuckers weaken host plants by removing their food supply. Scale insects are about 2-3 mm long and produce a sticky substance called honeydew, a food source for sooty moulds. The resulting red, brown or black coating reduces a plant’s ability to photosynthesise and looks unsightly.
Tip: Apply pure eucalyptus oil to affected leaves.

Cabbage white butterfly
This butterfly’s babies are bad news for your veggie patch. Its caterpillars favour cabbages, cauliflower, broccoli, celery and beetroot. Adult female moths have white wings and a black spot on each forewing.
Tip: Plant plenty of rosemary, mint, dill, sage, garlic, thyme, oregano and chamomile throughout your garden to deter them.

Mites
Mites are closely related to spiders and most have four sets of legs. These tiny arachnids puncture plants with their fangs and suck up the juice. Infested plants have silvery mottling and their leaves and stems end up covered with webbing.
Tip: Keep outdoor plants well watered and spray indoor plants regularly with a mist of water – mites thrive in dry conditions.

Thrips
Adult thrips feed in the blossoms of fruit trees, vegetables and ornamental garden plants, causing blossoms to turn brown and fall off, and preventing fruit from setting. Hatched offspring feed on flowers alongside their parents.
Tip: Apply pyrethrum (made from chrysanthemum blossoms) on affected plants and keep them well watered.

Slugs and snails
Silvery trails leading to large holes in leaves are telltale signs that these culprits call your garden home. Slugs and snails feed mostly at night and some can live for 12 years.
Tip: Handpick and drown in soapy water rather than stepping on them (their eggs may still hatch). Create barriers around plants with crushed eggshells or sawdust.

Ants
These hard-workers are attracted to the honeydew excreted by pests such as aphids, scale and mealybugs. Uncontrolled, ants can spread these insects throughout your garden by shifting their eggs onto fresh, new growth.
Tip: Paint a 6 cm-wide band of horticultural glue (made from natural gum resins, vegetable oil and wax) on stems and trunks. Other deterrents are mint and garlic.

Flies, fleas and mosquitoes
These nuisances can drive humans (and their pets) to distraction. Fortunately, there are several natural solutions.
Tip: Fight fleas with tansy, pennyroyal, spearmint and fennel; deter flies with basil, mint, rue and tansy; repel mosquitoes with garlic, tansy and pennyroyal, and plant sassafras near windows and doors. Ward off fruit fly with basil and tansy plants.

Mealybugs
Mealybugs are covered in a whitish ‘mealy’ wax to protect their soft bodies from water loss, and prefer warm, humid, sheltered sites. These insects can attack plants in huge numbers and do considerable damage by sucking up plant nutrients and depositing toxins in their place.
Tip: Ladybirds eat mealybugs – attract them with nectar and pollen-producing plants.