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.
Gardeners dread those irregular dead patches appearing in the lawn each spring. Digging reveals fat, creepy looking grubs – the culprits behind the damage. These are leatherjackets, the little-known larvae of crane flies wreaking havoc below ground. Learn how to identify these pests and protect your garden from their feeding frenzy.
What are Leatherjackets?
- The larvae of crane flies, also called daddy longlegs
- There are around 350 crane fly species in the UK, but only a few cause damage
- Leatherjackets grow up to 30mm long and are grey-brown in color
- They have an elongate, tubular body shape with no legs
- During larval stage, they feed on plant roots, especially turfgrass
- In gardens, main damage is to lawns, but seedlings can also be affected
The Crane Fly Life Cycle
- Adults emerge August-October to mate and lay eggs in soil
- Eggs hatch into larvae a few weeks later
- Larvae feed on roots through fall, winter, and spring
- By summer, mature grubs pupate into adult crane flies
- Wet autumns and mild winters favor survival and damage
Signs of Leatherjacket Activity
- Yellowish brown dead patches in lawns
- Grass lifts up easily from soil in damaged areas
- Seedlings eaten through at soil line or collapsing
- Presence of grubs when digging in affected areas
- Crows, magpies, and starlings pecking lawn hunting for larvae
Managing Destructive Leatherjackets
Biological Control
- Apply beneficial nematodes like Steinernema feltiae
- Most effective when soil temperature is above 54°F
- Target turf edges and hot spots to stop spread
- Apply September-October to kill young larvae
Prevention
- Improve lawn drainage and aeration
- Avoid over-feeding turf with nitrogen
- Allow grass to grow longer to hide minor damage
- Reseed damaged areas to keep lawn thick
Manual Control
- Lay black plastic over affected areas to draw larvae up
- Hand pick grubs from soil surface for disposal
- Encourage natural predators like birds and moles
Chemical Control
- No effective pesticide options are available to home gardeners
- Take care applying nematodes to avoid harming beneficial insects
The Role of Crane Flies in Ecosystems
While leatherjackets cause headaches for gardeners, most crane fly species are harmless or even beneficial:
- Many adult crane flies don’t feed at all
- Larvae of most species feed on decaying organic matter
- This contributes to nutrient recycling in soil
- Some larvae prey on pest grubs and worms
- Crane flies are an important food source for birds
So despite the damage caused by a few species, these insects remain integral to local ecosystems. With some prevention and control, gardens can coexist with leatherjackets and experience minimal impact. A thick, healthy lawn is the best defense against occasional crane fly chaos!
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
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 flies damage leatherjacket grubs?
They have long thin legs, narrow bodies and slender wings. 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 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.