Pests: Leather jackets
Pests: Leather jackets
By Laurence Gale Msc
What is a pest? By definition a pest is a living organism that negatively impacts on agriculture/sports turf operations and/or wildlife habitats. This includes plants, noxious weeds, insects, diseases, birds, animals and rodents, in fact anything that affects the performance and well being of natural turf is considered a pest by groundsman. This may also include the actions of fellow human beings who sometimes accidentally damage the turf whilst carrying out maintenance operations.
However, in general, the term 'pests' relates to insects, birds and mammals.
Problems occur when there is an inbalance in nature and these pests become dominant in a given environment. Luckily, for us in the UK, turf grass pests are indeed very few. However, what pests we do have can cause considerable damage to turf by the impact and relationship these pests have with one another, usually influenced by the feeding chain of these species.
For example, the chafer beetle in its adult form does not cause much damage in turfgrass situations. It is when this insect is in the larvae stage of its life cycle that it becomes a problem. The larvae remains in the ground at a depth of around 80-150mm and feeds on the root tissue of plants. Large infestations can destroy large areas of turf. The problem is compounded when mammals and birds begin feeding on the larvae resulting in heavy surface damage.
In the coming weeks we will feature and identify a number of turf pests, detailing their life cycle, activities and ways you can control them.
Understanding the life cycle and feeding habits of pests will help you reduce the impact and damage that can result from their activities.
This week's Pest is: Tipula paludosa (daddy long legs)
Leather jackets are a widespread pest problem on sports turf, particularly on golf courses in the UK and throughout Europe. Leather jackets are the larvae of the cranefly (Tipula species) more commononly known as Daddy long legs. There are many species of cranefly, however the main culprit is a species called Tipula paludosa.
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Scientific name Common Name Life cycle |
Tipula paludosa Leather jackets/daddy long legs One year life cycle (egg , larvae, pupae , adult) |
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Introduction |
Leather jackets can cause serious amounts of damage, particularly in fine turf situations such as golf greens, tees, fairways and bowling greens. During the larvae stage, the grub is actively feeding on plant root/shoot tissues. The severity of the feeding will and can result in turf decline or death. Shallow rooting grass varieties can find it more difficult to recover after an attack, especially during the winter months when grass growth has slowed down or stopped due to reduced tempretures. Damage can be devastating, especially when you get large infestations of more than 1000 leather jackets m2 in the turf. Further damage can occur when predators of the leather jackets (larvae/ pupae stage), namely badgers and birds are feeding. In their quest to find the larvae they end up digging and damaging the turf surfaces. |
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Eggs |
Eggs laid during September and October. The female lays about 600 eggs within hours of her emergence. The eggs are brown in colour and are dispersed around a site.The eggs are laid in the soil close to the base of grass stems/roots. The eggs hatch out after about 14 days, turning into larvae. |
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Larvae |
The larvae (leather jackets) feed from late September-June, when active. These larvae are generally found in the top 75mm layer of the soil profile. The larvae begin to feed on the stems and roots of grass plants, however, the larvae can often be seen feeding on leaf tissue on the grass surface during damp evenings. The larvae are generally grey/brown or green/grey in colour with no legs and no distinct head.the larvae grow in stages growing from 0.3cm-1cm by November, then growing between 2.5-4cm after feeding in the spring. |
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Pupae |
The larvae move down the soil profile in summer (July-August) to pupate, then begin the process of moving back up the soil profile in late August/September to emerge as adults. |
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Adult |
Adult craneflies (daddy long legs) emerge and are seen in late August-September. Females mate as soon as they emerge and then burrow back into the soil to lay their eggs. Adult craneflies do not damage turf, nor do they bite or sting. They are harmless. |
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Habitat |
Craneflies require grassland, amenity and sportsturf on a sandy/loam, free draining soil environment to lay their eggs and for the larvae to feed. |
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Symptoms |
The damage to the grass is seen as patches of dead and dying grass coupled with yellowing of the turf, especially during dry periods. Where there has been severe infestations of leather jackets the sward will be weakened to such an extent that the turf can easily be damaged by wear and tear from play or feeding birds and animals. Excessive burrowing by the leather jackets, when active, can also cause surface disruption, particularly on golf greens. Turf damage is also caused by other creatures that feed on the leather jackets. Moles, badgers and birds are the main predators. |
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Cultural Control |
Good cultural practices will increase the sward's ability to overcome damage from root loss and leaf damage. A strong, healthy plant is able to recover quickly and develop new rooting structures to compensate for any damage caused during the feeding. The use of tarpaulins or plastic sheeting covers, placed on the turf and left overnight, encourages the leather jackets to come up to the surface, where they can be collected or swept off. Controlling soil moisture can also help reduce the number of leather jackets. The larvae, when small, are susceptible during drought conditions. Improving soil drainage may help reduce their populations. |
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Chemical Control |
Chemical control is available but its efficiency can be compromised by many factors:-
Use pesticides as a last resort, but when you do, ensure you use and apply in accordance to the manufacturer's instructions and at the correct dosage. Applying inappropriate doses will lead to the pest becoming resistant to the active ingredients of the pesticide. In the past there were a number of chemicals that had good control of leather jackets (DDT, Aldrin, Gamma -HCH and Chlordane) however, these products are no longer available. Today the only active chemical control now available for use on controlling leather jackets is Chlorpyrifos. Current products available:-
Most of the above products recommend that they are used from November to March when soil moisture content has improved. These pesticides are usually applied as a liquid using watering cans, knapsack sprayers or vehicle mounted sprayers. Ensure you follow manufacturer's directions, health & safety and product data sheets, and comply with COSHH regulations when using chemicals. Pesticides are an effective tool where high quality turf is desired. However, they must be applied with care and accuracy and in the context of a good overall turf management programme. Before using any pesticide, carefully view the label for conditions of use including rates, methods of application and precautions. Be careful not to pollute water courses or endanger other wildlife when using pesticides, only use on its intended target. |
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Other controls |
Other methods have been used to control leather jackets in the form of bacteria and other organisms such as Nematodes, but these tend to be difficult to control and implement. Although not all that easy, try and prevent mammals and birds from feeding. Methods may be influenced by the fact that the bird or mammal is protected under legislation, badgers for example. You need to seek advice on how to deal with badger activity. |