The Leatherjackets feed on the roots of the grass plant making the plant more susceptible to disease and killing the plant. Major damage to the turf can be done by predators that are after an easy and abundant meal, starlings and other birds can congregate in vast numbers and decimate surfaces in a very short period of time. Climatic factors play a larger role in population control than the presence of predators. Damage to turf can be seen from September through the autumn, winter and into the spring.
Identification
The first indication of a problem is usually birds pecking and damaging the surface, in severe infestations the turf turns yellow in patches and bare areas start to appear. Lift back the turf to find Leatherjackets feeding on the roots of the grass plant; they generally feed at the edge of an infected area. The larvae are a typical grub shape: an elongated grey/brown tubular body without any legs, up to 30mm long. The adults look similar to very large mosquito’s although they have a very distinct ungainly flight unlike a mosquito’s flight. Their bodies are long and thin, so much so, that it is very easy to break off their legs when trying to catch them. Adult Crane Flies do not damage turf, nor do they bite or sting.
Lifecycle
• The adults hatch from grassland in August and September.
• Adults mate and lay eggs in grassland.
• Eggs hatch two to three weeks later and the larvae start to feed on grass roots throughout the autumn and into the spring.
• The grubs pupate in late May and June.
• The adults hatch from grassland in August and September.
Methods of Control
Attention to the problem is generally brought about by predators although preventative measures as well as curative action can be adopted to help prevent Leatherjackets damaging areas of turf. Control of Leatherjackets is relatively easy using broad-spectrum insecticides but distinguishing which areas require applications in advance of the damage remains the major problem.
Biological control – The nematode Steinernema feltiae is commonly used as a biological control. seek out the leatherjackets and attack the pest by entering natural body openings. The nematodes infect their host with a bacteria which stops the Leatherjackets from feeding, quickly killing them. The nematodes then feed upon the Leatherjackets, breeding and dispersing to encounter further Leatherjackets.
