Lepidoptera : Geometridae and Noctuidae

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Image above: Green Looper 
(image courtesy of Elise Dando)

Loopers are the larvae (caterpillars) of various moth species. The larvae are called ‘loopers’ because of the way they move. Larvae grip the surface with their forelegs and arch their back as they move their hind legs up to just behind their forelegs, creating the ‘loop’. Taking a firm grip with their hind legs, they reach forward and start the process again, inching forward as they do.

Loopers that may cause problems in the garden include:

  • Twig Looper Ectropis excursaria and Apple Looper Phrissogonus laticostata from the family Geometridae
  • Green Looper Chrysodeixis eriosoma, Tobacco Looper Chrysodeixis argentifera, and Soybean Looper Thysanoplusia orichalcea of the family Noctuidae.

There are many other harmless native loopers which breed in native plants such as wattles, grevilleas and eucalypts. Just because they are feeding on a plant, doesn’t make them a pest.

Best Treatment for Loopers

Control of Loopers starts with keeping an eye on your plants, so that you can detect caterpillar damage early. For example, you could watch for minor leaf damage in the veggie garden, or Looper damage to buds and fruit while watering.

For this to work, you will need to know what to look for (see Symptoms of Looper Damage). If you find damage, you should have a closer look to see if you can find the culprits – therefore, caterpillars. To confirm that it is Loopers, you will need to know what they look like (see Description).

Prevention is always better than cure, and you are more likely to be able to achieve that if you are out and about in your garden regularly. There are several things that you can do to prevent serious damage from Loopers (see How to Prevent Loopers Appearing). Regular monitoring of your garden will ensure that a major infestation of Loopers doesn’t occur ‘overnight’.

If you need to control Loopers, use Yates Nature’s Way Caterpillar Killer - Dipel. The product is based on naturally occurring bacteria (Bacillus thuringiensis), which acts as a stomach poison against caterpillars. The product will only affect Loopers and other caterpillars, so your ‘good bugs’ are safe. Follow the label directions and it will work against Loopers in your garden.

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Image above: Twig Looper

What are Loopers &
How to Get Rid of Them

Loopers are caterpillars that move in a distinctive way and are mostly larvae from two moth families (Geometridae and Noctuidae). The loopers from the family Noctuidae are technically called ‘semi-loopers’, to differentiate them from Geometridae, but in this article they are all described as ‘Loopers’.

Twig Looper Ectropis excursaria (Geometridae) is known by several other common names, including Pear Looper and Common Bark Moth. It is a native moth widely distributed throughout eastern Australia and also the south-west of Western Australia. The adult moth is light brownish-grey with wavy patterns across its wings, and the moth has a wingspan of about 30 - 40 mm. The moth rests with its wings stretched out to either side. Unfortunately there are hundreds of moths within the family Geometridae that could be described this way. Larvae vary considerably in colour from greenish-grey to reddish-brown and are about 40 mm long when mature. The larva is known as a ‘Twig’ Looper because it stretches out straight and camouflages itself as a twig when it is not feeding.

Apple Looper Phrissogonus laticostata (Geometridae) is a native moth which occurs across most of Australia. The adult moths are mottled brown with grey wavy patterns across the wings, and have a wingspan of about 15 mm. The moth rests with its wings to the side forming a rough triangle. Once again, there are many moths within the family Geometridae that might fit this description. Larvae are variable in colour from green to mottled brown, and mature larvae are thin caterpillars about 20 mm in length.

Soybean Looper Thysanoplusia orichalcea (Noctuidae) is an introduced species, which is now widely distributed in eastern Australia. There are also a few isolated records from southwestern Western Australia where it is a declared pest. The adult moth is an overall reddish-brown to olive-brown colour with an orange head. The forewings have a large, L-shaped metallic gold patch which gives rise to its other common name - Slender Burnished Brass moth. It has a wingspan of about 35-45 mm and rests with its wings held over the body like a gable roof. Larvae grow to about 35-45 mm long and are yellow-green to blue-green with white and dark longitudinal markings and are sparsely covered in long white hairs.

Green Looper Chrysodeixis eriosoma and Tobacco Looper (aka Vegetable Looper) Chrysodeixis argentifera (Noctuidae) are greyish-brown moths with conspicuous silver markings on their wings with a wingspan of 30-40 mm. They hold their wings like a roof over their body when resting. Larvae are bright green, fleshy caterpillars (20-30 mm long) with white stripes running the length of the body and they are sparsely covered in greyish hairs.


Life Cycle

All loopers develop through a life-cycle of complete metamorphosis – egg, larva, pupa, adult moth.

Small, white, spherical or ovoid eggs are laid on the underside of leaves or near fruit (depending on the species), from which larvae hatch and develop through several instars, increasing in size at each moult. Larvae pupate in cocoons spun on the underside of leaves or in folded leaves or in the soil depending on the species. Moths emerge from the pupae to begin another generation. There are usually several generations per year.

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Image above: Green Looper

What Plants are Impacted by Loopers

Apple looper: apple trees, sunflowers, clematis and wattles.

Twig Looper: rose, geranium, gardenia and weeds such as capeweed. A large range of natives, including eucalypts, wattles and tea tree. Minor pest of pears.

Soybean Looper: soybeans, brassicas, sunflowers, potatoes, parsley, pumpkins, melons and chrysanthemums. They also breed in weeds.

Green Looper & Tobacco Looper: many plants, including ornamentals such as dahlia, geranium and rose; vegetables and fruit, including beans, brassicas, potato, silverbeet, strawberry and tomato. They also breed in and feed on many broadleaf weeds.

Symptoms of Looper Damage

  • Damage to pome fruit trees by Apple Looper and Twig Looper is usually limited to small holes in leaves and grazed surface to fruits, resulting in a scabby appearance. The fruit is still edible.
  • Green Looper, Tobacco Looper and Soybean Looper may chew large holes on the underside of leaves, and in pods and fruit.

How to Prevent Caterpillars Appearing

Monitor

  • Look for loopers under the leaves, and small holes in leaves and grazed fruit.

Prevent

  • Most Loopers feed on and breed in weeds. Remove weeds to reduce the number of breeding sites available to looper moths.
  • Protect crops and other plants with fine netting.
  • Squash any eggs you find, to prevent larvae emerging. Pick off large caterpillars and squash or dispose of them in a plastic bag.

Natural enemies

  • Tiny parasitic wasps destroy the eggs of Looper moths (see beneficial wasps).
  • Parasitic wasps and flies parasitise larvae.
  • Assassin bugs, damsel bugs, lacewing larvae and ladybirds eat larvae.

Recommended products to control Loopers


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