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In the middle of summer, your lawn is looking pretty bad, and you’re wondering about leatherjackets, those ugly bugs you may see pushing up through dead spots and dry grass. Read on to learn more about destructive leatherjacket pests and leatherjacket grub control.
Leather jackets are the larvae of crane flies also known as daddy longlegs. While there are many harmless species some leather jackets can be problematic in gardens by feeding on the roots of grass and plants. Let’s take a deep dive into understanding these intriguing insects.
What are Leather Jackets?
Leather jackets refer to the larval stage of crane flies. They get their name from their tough, leathery skin. There are around 350 species of crane flies in Britain, and only a small number cause damage by feeding on living plants.
Leather jackets are elongate, tubular grubs up to 30mm long with greyish brown skin. They have no obvious legs or head. Instead, they have a distinguishable ring of finger-like projections at the tail end.
Life Cycle of Crane Flies and Leather Jackets
The life cycle of crane flies includes four main stages
Adult Crane Flies
- Resemble large, gangly mosquitoes with very long legs
- Most active in late summer through early fall
- Female lays up to 300 eggs in the top layers of soil
Eggs
- Laid in turf or soil from August to October
- May fail to hatch if soil is too dry
Leather Jackets
- Hatch in late fall and feed on plant roots through winter
- Cause most damage in spring when nearly grown
- Pupate in early summer
Pupae
- Formed within soil
- Adults emerge in summer
- Pupal cases left sticking out of the ground
Identifying and Preventing Leather Jacket Damage
It’s important to accurately diagnose leather jackets, as their damage can resemble other problems like disease or poor growing conditions:
- Yellow or brown patches in lawns – Lift affected sections to find grubs in soil
- Seedlings/plants killed at soil level – Stems are chewed through
- Small round holes in turf – From birds like crows digging for grubs
- Pupal cases protruding from soil – Sign adults recently emerged
To help prevent issues, apply beneficial nematodes like Steinernema in early fall as a spray into soil. The nematodes infect and kill the grubs.
Management of Leather Jackets in Lawns and Gardens
If leather jackets are already actively damaging plants, here are some management options:
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Encourage natural predators – Birds, ground beetles, and parasitic wasps help control populations. Avoid pesticides that may harm them.
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Nematode application – Use Steinernema species in affected areas. For best results, ensure soil is moist and at least 54°F.
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Remove food sources – Eliminate lawn thatch and clear decaying vegetation that larvae feed on.
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Hand removal – Dig up and dispose of grubs, taking care not to damage plant roots.
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Re-seed damaged turf – Repair bare patches in lawns once grubs are controlled.
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Avoid excess fertilizer – High nitrogen levels favor crane fly reproduction.
Fun Facts About Crane Flies and Leather Jackets
Beyond being occasional lawn pests, crane flies and their larvae are fascinating insects that play an ecological role:
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Crane fly adults only live for about 10-15 days and do not all even feed.
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Some leather jackets are predacious and feed on other soil-dwelling insects and grubs.
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Leather jackets help decompose organic matter, recycling nutrients in the soil.
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Adult crane flies are sometimes called “mosquito hawks” but they do not actually eat mosquitoes.
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Birds like starlings often damage turf as they dig out leather jackets to eat.
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Crane flies are clumsy fliers and are attracted to lights at night.
Understanding the biology and behavior of crane flies and leather jackets can help in keeping them from becoming a nuisance while still appreciating their contributions to the garden ecosystem. With some preventive care and proper identification, leather jackets can be managed without disrupting the balance of nature.
Leatherjacket Pests in Your Lawn
Exactly what are leatherjacket insects? Leatherjacket pests aren’t actually insects. The grub-like bugs are the young stages of daddy long legs, which are also called leatherjacket crane flies. These are the big bugs that look like mosquitoes and fly around your porch light in the late summer. Because they live in the ground, leatherjacket pests can do a lot of damage when they eat plant roots and bases. Adult leatherjacket crane flies lay their eggs in the grass in late summer. After two or three weeks, the eggs hatch, and the tube-shaped, grayish-brown larvae start eating plant roots right away. Leatherjacket bugs spend the winter in the ground and usually don’t do much damage until late spring or early summer, or even earlier if the winters are mild. As soon as the larvae are fully grown, they pupate in the soil. You may be able to see the empty cases sticking out of the ground.
Controlling leatherjacket larvae in your lawn isn’t always necessary. If you’re lucky, leatherjackets may be snatched up by hungry crows, magpies, or robins (or even cats). The only bad thing is that birds may damage your lawn by pecking at the ground to find the juicy grubs. There may be biological, organic, or even chemical ways to get rid of leatherjacket larvae in your lawn if the problem is bad.
- Biological control—A helpful nematode with the long and complicated name Steinememe feltiae can get rid of leatherjacket grubs. When the eelworms, which are tiny nematodes, get into the bodies of leatherjacket larvae, they give them a bacteria that kills them. Nematodes, which can be bought at garden centers under a number of easier-to-pronounce names, are usually used as a preventative measure in the fall.
- To use organic control, you should water the area well (or wait for it to rain) and put black plastic over the area that is hurt. Put the plastic down overnight, and in the morning, take it off along with the grubs that are stuck to it. Be careful as you pull the plastic up, or the grubs could get out and go back into the soil. ). It’s a bad job, but this way of getting rid of the grubs works very well.
- Chemical control—Chemicals aren’t usually a good idea, and they should only be used by a professional pest control service as a last resort. You might find useful things at your local garden center, though.
Lawn Pests – Leatherjackets Infestation
FAQ
How to get rid of leather jacket larvae?
Is a leather jacket a crane fly?
What is the best killer for crane fly larvae?
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.
Are leather jacket flies destroying your lawn?
The larvae of crane flies, known as leather jackets, can be damaging to lawns and are worth dealing with as soon as possible to avoid further damage. If you’re keeping on top of your lawn care but find your lawn is yellow still, leather jackets could be the problem. These pests feed on grass roots, causing dead and discolored patches.
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.
How do you kill European crane fly larvae?
You want to kill European crane fly larvae when they’re most active – usually in early to mid-April. Using a drop spreader or broadcast spreader, apply Ortho® BugClear™ Insect Killer for Lawns around your property. It kills by contact above and below the soil and will create a bug barrier that lasts three months.