Psyllids (pronounced sillids) are sap-sucking insects related to Aphids, Whiteflies and Scale Insects. The most common Psyllids in gardens are members of the families Psyllidae and Triozidae, and there are about 400 species that occur in Australia.
Australia has a unique group of psyllids that produce sugary waxy coverings known as lerps, which are common on Gum Trees.
There are other psyllids that cause galls to form on the leaves of Gum Trees, as well as the notorious Lilly Pilly Psyllid, which cause gross distortions of Lilly Pilly leaves. There are also free-living psyllids that dont form galls or lerps.
Basket grass, also known as oplismenus aemulus, is a common lawn and garden plant found in many yards and landscapes. While an attractive groundcover, basket grass is prone to infestations by a pesky insect pest known as lerps. Lerps are sap-sucking bugs that can quickly damage and degrade the appearance of basket grass. Getting rid of lerps on basket grass requires persistence and utilizing a combination of control methods. With some knowledge and effort, you can eliminate lerps and restore the health of your basket grass plant.
What are Lerps?
Lerps are tiny, sap-feeding insects that belong to the order Hemiptera and family Psyllidae There are many different species of lerps, but they all produce a protective sugary coating over their bodies while feeding on plants. This white or clear covering resembles scales and is secreted from the abdomen of the insects Underneath the scales, lerps pierce plant tissues with their snout-like mouthparts and feed on sap.
Lerps go through multiple nymph stages beneath the protective coating before maturing into winged adults that can fly and infest new plants The lerps covering provides camouflage and shields nymphs from natural enemies and pesticides Lerps infestations can build up rapidly, with multiple generations produced over a single growing season.
Signs of Lerps on Basket Grass
Detecting lerps early is key to successful treatment. Be on the lookout for these common signs of lerps on basket grass:
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White or clear bumps on leaves that resemble scales or waxy deposits. These are the protective lerps coverings.
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Leaf yellowing, curling, distortion, stippling, or scorching. This foliar damage results from lerps feeding.
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Presence of black sooty mold on leaves. Sooty mold grows on the sugary honeydew secreted by lerps.
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Leaf drop or thinning turf. Heavy lerps feeding can stunt plants and thin out grass stands.
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Clusters of small (1-3 mm), clear to brown winged insects on leaves. These are the adult lerps.
Catching infestations when they first start is critical to getting lerps under control.
How to Get Rid of Lerps on Basket Grass
Once lerps are detected on basket grass, implementing control measures quickly can eliminate the infestation before major plant damage occurs. Here are effective options for getting rid of lerps on basket grass:
Encourage Natural Enemies
Ladybugs, lacewings, spiders, and tiny parasitic wasps prey on lerps. Attract these beneficial insects by avoiding broad spectrum insecticides and planting flowers that supply nectar and pollen. Natural enemies can help suppress lerp populations.
Remove By Hand
For light infestations, simply wipe lerps off leaves with a moist cloth or soft brush. Crush them or drop in soapy water to kill. Be sure to check undersides of leaves where lerps often gather. Repeat hand removal regularly to control small lerp populations.
Apply Horticultural Oils
Coating plants with lightweight horticultural oils suffocates lerps and other soft-bodied insects. The oil also helps prevent new infestations. Mix oil according to label directions and spray on basket grass until leaves are completely wet. Reapply every 7-14 days for 2-3 weeks. Oils are safe for most plants.
Use Insecticidal Soaps
Insecticidal soaps kill lerps on contact by dissolving their waxy outer covering. The soaps allow insects to dry out. Spray mixed soap solution on basket grass, especially under leaves, as directed on the label. Reapply every 5-7 days for 2-3 weeks to kill newly hatched lerps.
Apply Neem Oil
Extracted from the neem tree, neem oil kills lerps and suppresses further infestations. It contains azadirachtin which disrupts the growth and molting of juvenile insects. Spray basket grass leaves thoroughly with neem oil mixed according to label instructions. Reapply weekly for several weeks. Neem oil is non-toxic to people, pets and plants.
Use Systemic Insecticides
Systemic insecticides are absorbed by plants and make their tissues and sap toxic to feeding insects. Products containing imidacloprid or acephate applied as a soil drench or granules can kill lerps on contact and provide residual control for several weeks as plants take up the insecticide. Always read and follow label directions carefully when using any insecticide.
Maintain Plant Health
Healthy, vigorous basket grass is less susceptible to lerp attack. Be sure to meeting the plant’s cultural requirements for sun exposure, irrigation, drainage and soil nutrition. Prune or mow to remove any dead or heavily infested stems and foliage. Proper lawn care and fertilization will encourage the grass to outgrow damage.
Preventing Lerps from Returning
Prevention is key to avoid recurring bouts with lerps on your basket grass. Here are some tips:
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Inspect plants frequently and treat quickly at the first sign of lerps before they multiply.
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Remove any alternate host plants like paperbark trees that can harbor lerps near basket grass.
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Dispose of clippings after mowing or pruning to eliminate any lurking lerps.
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Consider applying a systemic insecticide annually at the start of the growing season for residual protection.
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Promote beneficials that feed on lerps by avoiding broad spectrum insecticide use and providing nectar plants.
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Adjust irrigation to avoid excessive wetness on leaves which encourages lerps and other pests.
Lerps can be challenging to control but taking a persistent, multi-pronged approach using several different treatment methods together can usually eliminate infestations on basket grass. The key is thorough coverage and repeating treatments on a regular schedule to break the lerps life cycle. Maintaining plant health through proper care and preventative management will also help avoid severe lerp issues. With vigilance and dedication to control measures, you can get rid of destructive lerps and enjoy lush, beautiful basket grass once again.
What are Psyllids & How to Get Rid of Them
Psyllids are also known as jumping plant lice. That name comes from the ability of adult psyllids to catapult themselves into the air to escape from predators. Their leap is unique in that they rotate rapidly forwards, like a tumbling gymnast, many times per second as they spring upwards.
Many species of psyllids form lerps on Gum Trees, and they may occur anywhere in Australia. Some psyllid species only feed on specific species of Gum Trees. Psyllid nymphs form the lerps – a white, sugary, waxy covering – from their own liquid excretions as protection from desiccation and predation.
Lilly Pilly Psyllid (Trioza eugeniae), also known as Pimple Psyllid feeds on several tree species of three allied genera known commonly as Lilly Pillies. The insect is found in eastern Australia from South Australia to north Queensland.
The exotic Tomato Potato Psyllid (Bactericera cockerelli) is a recent arrival in Western Australia, and so far, is confined to that state. It is a free-living psyllid that does not form galls or lerps.
Adult Psyllids resemble tiny Cicadas with their clear wings in an inverted v over their bodies. Adult psyllids are usually about 2 – 3 mm in length.
Psyllid nymphs are miniature versions of the adults but without wings and hidden under the lerp. The appearance of a lerp varies between species, from simple sugary cones, shells and scales to intricately woven baskets and fans. The common name of these species usually describes the lerp (e.g., White Lace Lerp or Brown Basket Lerp).
The adult Psyllid has a dark brown body and clear wings. Eggs are yellow, elongated, and about 0.5 mm long. Lilly Pilly Psyllid nymphs are soft, flattened, scale-like, pale creatures about 1 mm long.
Nymphs are hidden inside galls. Common galls on Eucalypt leaves caused by the psyllid Schedotrioza are large spherical, red and green distortions.
Nymphs are miniature versions of the adults but without wings. Nymphs may exude waxy material. Eggs are usually yellowish.
The adult is brownish with pale markings, and a broad white band on the abdomen. Nymphs are yellowish, oval-shaped, and flattened with red eyes. Older nymphs are fringed with hairs.
Psyllids pass through a life cycle of gradual metamorphosis – egg, nymph, and adult.
Adult females lay eggs on leaves, either singly or in batches. They may lay several hundred eggs over their lifetime. Some species like to lay eggs on young leaves, while others prefer mature leaves. First instar nymphs (crawlers) hatch and crawl to a suitable feeding site, begin feeding and start to build their lerp. Larvae pass through five instars under their ever-expanding lerps, before emerging as tiny winged adults. There are usually several generations per year.
Adult females insert their eggs in the margins of freshly expanding leaves. Hatching nymphs move to a suitable position on the underside of a leaf and begin feeding. After the first moult, a shallow pit begins to form under the nymph, which increases in size as the nymph goes through further moults. After the final moult an adult psyllid emerges, and the cycle begins again. Lilly Pilly Psyllid can only complete its life cycle on expanding leaves, not mature leaves.
Adult females insert groups of eggs into leaves. Nymphs hatch and burrow into the leaves, which causes galls to form. Each gall on a leaf contains one nymph. Eventually the nymphs reach adulthood and emerge from the galls.
Eggs are laid on the growing shoots of host plants. Nymphs hatch and pass through five growth stages before adulthood. Adults and nymphs at various growth stages are seen together feeding on the green shoots of plants.
Eggs are laid on leaf edges or the underside of leaves. Nymphs hatch and pass through five growth stages before adulthood. Nymphs and adults are usually found together on leaves. There are several generations per year.
What Plant are Impacted by Psyllids
- Lilly Pillies especially Syzygium paniculatum and Waterhousea floribunda.
- Native plants, especially Wattles and Gum Trees, occasionally Kurrajongs and Grevillea.
- Some free-living psyllid species may also attack Murraya hedges.
Tomato Potato Psyllid (W.A. only)
A light infestation of lerps usually results in a motley appearance to leaves and/or purple patches on leaves. Some Sooty Mould may form on excess sap excretions. Plants that have already been stressed in some way, for example by drought, are particularly vulnerable to psyllid damage. A severe infestation may cause excessive defoliation, which leads to a decline in tree health and growth and, in extreme circumstances, tree death.
Nymphs cause pit galls on the underside of flush growth leaves of Lilly Pillies, which cause corresponding pimply distortions on the upper side of leaves. Severe infestations cause extreme leaf distortion and stunting of plants. Attacks are very unsightly but not fatal.
Obvious woody galls on the leaves of Eucalypts. They can be ignored or just picked off if you find them unsightly.
Colonies of tiny insects congregating on young shoots of plants. Waxy secretions, Sooty Mould. Shoots and leaves may be deformed.
Upward rolling of leaves, new foliage tinged with purple and stunted growth.
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FAQ
How to get rid of lerps?
How to eradicate basket grass?
How to get rid of psyllids naturally?
What is a natural spray for psyllids?
How do I get rid of basketgrass?
Another option is to spot treat with an herbicide, making sure to spray only the weed and not desirable plants. If basketgrass is a significant weedy problem, you can apply a granular, pre-emergence herbicide that will inhibit weed seeds from sprouting.
What should I do if I don’t like basketgrass?
If a homeowner does not like the look of basketgrass in shady areas of the landscape, we recommend mulch and low-maintenance plants. Ferns, bromeliads, Asiatic jasmine, coontie cycad, liriope–all are great alternatives in shady landscapes where basketgrass is not desired. The use of chemicals or manual removal is entirely up to the homeowner.
Can glyphosate kill basketgrass?
Over time, they may out-compete the basketgrass. An herbicide, such as glyphosate, may also be used to remove basketgrass. Use caution if spraying under or near trees and other plant material as glyphosate products are not selective and will damage and/or kill desirable plants as well.
How do you get rid of lerps organically?
How To Organically Control Lerps Wipe leaves clean with a damp cloth or cut off infested sections. Restrict ant access by applying a band of horticultural glue around the main trunk. Weekly doses of OCP eco-seaweed to help reduce plant stress. Improve plant heath by assessing the growing conditions and make the necessary corrections.