The Problem with Leatherjackets

Crane fly larvae, commonly referred to as leatherjackets, dwell in the upper layers of soil, where they feed on grassroots and plant material. Their presence is most prominent in transition months, and their activity can lead to fragile ground and poor turf condition. Public lawns may become difficult to maintain without proper control.

Detecting Larval Activity Quickly

Identifying larvae before serious damage occurs is beneficial. Watch for signs such as bird pecking, patchy grass, and irregular surface wear. Cut test squares in the turf to observe larvae beneath. Conducting these checks during cooler months supports better planning.

How the Seasons Influence Turf Health

Leatherjackets can continue feeding underground during milder winter spells. If they are not kept in check, the turf’s ability to recover in spring is hindered. Maintenance scheduling based on known behaviour helps reduce pressure on affected areas.

Tackling the Problem Without Chemicals

Turf professionals often begin with physical practices. Regular aeration encourages root growth and improves turf firmness. Raising mowing height during feeding periods can reduce stress, and rolling moist turf may disrupt larvae, leaving them open to natural predation. These approaches help improve turf quality, even if they do not eradicate the pests.

Natural Solutions

Nematodes, microscopic bioagents, offer a natural way to address larvae. They are most effective when applied during early autumn, under favourable moisture and temperature conditions. When timed and applied correctly, they suppress larval numbers and allow the turf to recover.

When to Use Approved Chemicals

In some cases—especially on high-demand surfaces—chemical treatment may be necessary. Registered turf protection products may be applied, but only according to label instructions. Blending chemical input with cultural and biological steps keeps treatment balanced.

Avoiding Repeat Infestations

To avoid outbreaks in future seasons, aim to optimise drainage, encourage strong rooting, and maintain steady nutrient levels. Monitoring turf after crane fly emergence in late summer helps predict larval activity levels for the months ahead.

Frequently Asked Questions

• When do leatherjackets feed the most?
  
  They tend to be active in greater numbers during mild periods in autumn and spring.



• How can I be sure I have a problem?
  
  Cut out a section of turf and count the number of larvae beneath. This provides a practical population check.



• Can nematodes survive in cold soil?
  
  No. They require specific temperatures and soil moisture to be effective.



• Does mowing height matter?
  
  Yes. Leaving grass slightly longer during larval feeding helps support plant health.



• Why are birds damaging my lawn?
  
  Birds often scratch where larvae are present. Their behaviour can be an unintended clue of infestation.

Final Advice

Managing crane fly larvae involves a mix of early detection, well-timed treatment, and varied management strategies. By combining physical methods, biological control, and limited chemical use, turf conditions can be protected throughout the year.

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