The Problem with Leatherjackets

Crane fly larvae, commonly referred to as grubs, dwell in the upper layers of soil, where they damage grassroots and decaying material. Their presence is most prominent in moderate seasons, and their activity can lead to soft ground and weakened turf condition. Public lawns may become unusable without proper control.

How to Spot an Infestation

Identifying larvae before serious damage occurs is beneficial. Watch for signs such as bird pecking, thinned areas, and irregular surface wear. Cut small patches in the turf to check for larvae beneath. Conducting these checks during early spring helps with timely responses.

Understanding Larval Cycles

Leatherjackets can remain active 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 seasonal patterns helps reduce pressure on affected areas.

Physical and Mechanical Solutions

Maintenance teams 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 expose larvae, leaving them open to natural predation. These methods help maintain turf quality, even if they do not fully eliminate the pests.

Biological Pest Control

Nematodes, microscopic beneficial organisms, 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 stabilise.

Supplementing with Registered Products

In some cases—especially on frequently used surfaces—chemical treatment may be necessary. Registered turf protection products may be applied, but only according to regulatory guidance. Blending chemical input with cultural and biological steps prevents overuse.

Reducing Future Risk

To minimise 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 indicates larval activity levels for the months ahead.

Frequently Asked Questions

• When do leatherjackets feed the most?
  
  They tend to be feeding in greater numbers during cool and moist 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 peck 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 coordinating physical methods, biological control, and limited chemical use, turf conditions can be maintained throughout the year.

Need professional help? Visit crane fly larvae control ALS Contract Services for more information.