Leatherjackets are the larval stage of crane flies, also known as daddy longlegs. These common garden pests can cause frustrating damage to lawns and plants if left unchecked. Though part of the natural ecosystem, leatherjackets have the potential to become problematic in home gardens when present in large numbers. This article will provide an in-depth look at identifying, understanding, and managing leatherjackets when they become a nuisance.
What are Leatherjackets?
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Leatherjackets are the legless larvae of crane flies. There are around 350 species of crane flies in Britain.
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They are given the name “leatherjacket” due to their tough, leathery skin. Mature larvae are greyish, tubular grubs up to 30mm long.
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Many species feed on decaying organic matter and help nutrient recycling However, some species can damage plants by feeding on roots
Recognizing Leatherjacket Damage
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Leatherjackets feed on grass roots, causing yellowing and dieback of lawn areas. This can appear as early as late winter in mild areas.
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Affected areas can be checked by lifting the turf and looking for grey grubs in the top layers of soil
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Seedlings and small plants may be damaged or collapse if larvae feed on stems at soil level
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Birds like crows and starlings may dig small holes in the lawn while foraging for the grubs.
The Leatherjacket Lifecycle
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Adult crane flies emerge late summer, mate, and females lay up to 300 eggs in the soil.
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Eggs hatch into larvae in early fall. Larvae feed on grass roots throughout fall, winter, and spring.
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In cold climates, larvae overwinter as small grubs and cause most damage in summer. In mild climates, they feed continuously.
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Mature larvae pupate in the soil in early summer. Adults emerge late summer to repeat the cycle.
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When new adults emerge, you may see pupal cases protruding above the soil surface.
Preventing Leatherjacket Issues
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Monitor for adult crane flies in late summer to determine potential egg laying levels.
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Maintain a healthy, vigorous lawn through proper mowing, watering, fertilization, and aeration. This helps the grass recover from larval damage.
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Avoid excess lawn thatch, which encourages larval populations. Dethatching in early fall can reduce numbers.
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Encourage natural predators like birds, ground beetles, and parasitic wasps which feed on leatherjackets.
Control Options for Existing Leatherjacket Populations
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Apply beneficial nematodes to the soil in early fall as a biological pesticide. Nematodes target and kill larvae.
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Use pheromone or LED crane fly traps in late summer to reduce egg laying adults.
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Insecticides containing carbaryl, imidacloprid, or trichlorfon can be used to reduce larvae but should be a last resort.
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Soak affected areas and cover with black plastic overnight to bring larvae to the surface for removal.
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Top dress lawns with compost in fall. Healthy microbial activity competes with and repels larvae.
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Aerate the lawn well in early fall to expose larvae to predators and dry out the soil.
When to Worry About Leatherjackets
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Damage normally appears in late winter and spring as larvae reach mature size.
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Mild winters allow for faster larval growth and earlier damage.
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High adult populations in late summer can indicate potential for high egg laying levels.
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Damage occurring over less than 25% of the lawn is unlikely to be detrimental long-term if the grass is healthy.
The Takeaway on Leatherjackets
While leatherjackets are a natural component of the garden ecosystem, their root damaging feeding habits can cause frustration for homeowners. Understanding their lifecycle and being proactive about prevention and monitoring for adults are key to avoiding serious issues. For existing populations, the use of biological controls, pheromone traps, and grass health management will provide the most sustainable results. With timely action and an integrated pest management approach, leatherjackets can be managed for minimal lawn and garden damage.
LeatherJacket Grubs – Crane fly larvae
FAQ
How do you treat leather jacket crane flies?
Leatherjackets are the larval stage of the crane fly or daddy long legs and they can quickly devastate a lawn. Control leatherjackets by treating with Nemasys® Leatherjacket Killer containing natural nematodes.
How do I get rid of leather jacket grubs?
The most effective solution is to either cover the whole lawn (or just the affected area) overnight with black plastic sheeting – this encourages the grubs to come to the surface so they can be brushed off and destroyed.
Are leather jackets the same as crane flies?
Leatherjackets are the larvae of craneflies.
What are the first signs of leatherjackets?
The most prominent symptom or sign of a leatherjacket infestation is the appearance of dead brown and yellow patches on your lawn. This means that your lawn seedlings have collapsed due to leatherjackets eating away within the soil.
Do crane flies eat leatherjackets?
The legs are very long and fragile and are easily broken off. Even though crane flies have a short proboscis, they are harmless to humans. Some crane flies feed on plant nectar, and it is thought that some crane flies do not feed at all. Maggots of crane flies called leatherjackets because of their tough skin that resembles leather.
Do crane fly lay leather jackets?
They lay the next generation of leatherjackets. The larvae of the European Crane Fly, known as “leather jackets”, are approximately 25mm long and have a grey/brown leathery skin. They are known for their destructive nature and can cause severe damage to lawns and other vegetation in the garden.
Do crane flies damage leatherjacket grubs?
Although several different kinds of crane-fly produce damaging leatherjacket grubs, they are hard to distinguish. They all do similar damage and are dealt with in the same way.
Are leather jacket flies grubs?
Leather jacket is the common name for larvae of the flies in the family Tipulidae, flies in this family are also known as ‘Crane flies’. Leatherjacket pests aren’t actually insects. The grub-like pests are the larval stage of daddy long legs, also known as leatherjacket crane flies.
Are leather jacket flies dangerous?
‘The larvae of crane flies are known as leather jackets. Their bodies are long, grey-brown and usually divided into segments. They are found under soil surfaces, especially on lawns or turf,’ says Allan Bossel, pest control expert. While leather jackets may not look intimidating, experts note they can cause quite a bit of damage to lawns.
Do leatherjacket flies eat plant roots?
Leatherjacket pests, which live in the soil, can definitely do their share of harm when they eat the roots and the base of plants. Adult leatherjacket crane flies lay their eggs in the grass in late summer. The eggs hatch two or three weeks later, and the greyish-brown, tube-shaped larvae immediately begin feeding on plant roots.