found in a small proportion of the population. It appeared to be transmitted by cannibalism which restricted its spread. Although there was some success by introducing it through treated bran. However, in field populations the leatherjackets must encounter the bran while it is viable which may prove difficult. Wide scale production of this virus would also be difficult as it cannot be produced in vitro (Blackshaw, 1991).


A parasitic wasp (genus Anaphes) has been found in Northern Ireland that was recovered from eggs, which may prove useful in future control methods (Blackshaw, 1991). However, the wasp has not been found in other areas of the UK and may not occur in other parts of Europe or the USA.


An entomopathogenic nematode (Steinernema feltiae) has shown promise in reducing leatherjacket numbers (Peters & Ehlers, 1994). The highest mortality (51%) of leatherjackets was shown to be just before the first molt (15 day old larvae) in a laboratory test. Mortality then declined as the leatherjackets move through the larval stages. The number of dauer juveniles (the life stage of the nematode that infects the leatherjackets) required to kill the leatherjackets also differed depending on the age of the leatherjacket. The lowest


LC50 was 7


dauer juveniles when the larvae were 6 days old increasing to 56 when the larvae were 72 days old. However, these results were for leatherjackets placed in sand filled petri dishes and the nematodes applied close to hand. A field trial would be required to determine the efficacy of nematodes in vivo when the leatherjackets may not be close to the site of application.


In the UK, this nematode


is currently on the market, aimed at lawn owners. We are unaware of anyone who has used this product and so do not have any information on its effectiveness. Bacillus thuringiensis var. israelensis (Bti) has also been suggested as a promising biological control agent (Evans, 1996). Autumn application of Bti to grassland in Scotland reduced the leatherjacket population from 3 million larvae ha-1 to 0.5 million larvae ha-1. This reduction was similar to chlorpyrifos applied at the recommended rate. However, spring application of Bti did not significantly reduce the leatherjacket population compared to the untreated control. Chlorpyrifos significantly reduced the leatherjacket population in the spring. In grassland, it is commonly accepted that the economic threshold for treating leatherjackets to prevent a decrease in yield is 1.0 million ha-1 (100 leatherjackets m2). Treatment with Bti in autumn brought the leatherjacket population


below this threshold. However, in managed amenity turf the threshold for pesticide application is 16 leatherjackets m2. Further work would be required with Bti to ensure it could reduce the population to an acceptable level for golf. Grass species infected with endophytes are often less susceptible to insect feeding due to their alkaloid content. Lewis & Vaughan (1997) investigated the effect of endophytes on the feeding behaviour of leatherjackets. Three perennial ryegrass varieties with and without endophyte infections were fed to leatherjackets in a laboratory experiment. There was no significant effect of endophyte infected ryegrass compared to no endophyte infection on weight, survival or number of adults that emerged. It was concluded that the levels of alkaloids may not have been sufficient enough to deter feeding by leatherjackets. The level of alkaloids produced differed depending on the


endophyte/plant genotype and the season. It is possible that other grasses infected with endophytes may produce improved resistance to leatherjacket feeding.


This article has been taken from a paper published in the Sports Turf Research Institute's annual "Journal of Turfgrass and Sports Surface Science",Vol 80, 2004.Copies are available from STRI tel:01274 565131. The author would like to thank the R&A for financial support in an expanded version of this article.


Days OFF! ... or what Pitchcare contributors get up to out of office hours


PATRICK CALLABY: commonly referred to as Cal (a nickname left over from Army days). The last 11½ years I have spent as workshop manager at The Celtic Manor Resort and previous to that at St. Pierre Hotel & Golf Course, Chepstow for 8 years. I have a passion for dogs in general, but gundogs used in the field in particular, especially the English Springer Spaniel. I have kept them for many years (we won’t go into how many). I must have owned 50 odd during this time and have had a certain amount of success in competition, and generally train a competent dog for field work. I currently have 6 in the kennels, one Golden


Retriever, 2 Clumber Spaniels (guests) and 3 English Springers.


My wife says I think more of those dogs than I do of her and my reply is I think more of next door’s dog than I do of her. Married to Maralyn for 34 years; I have 3 grown- ups to my name, a son aged 27 - maturing to about 16ish and twin boy & girl aged 24. My daughter, Gail, has a son, who, at 2 years old is bonkers about dogs (don’t know where he gets it from) and would live in the kennel with Bob (his favourite dog) given half a chance; he’s a lovely boy. Retiring age is fast approaching and since my pension fund is absolute rubbish I’ve had to resort to plan B, writing articles for Pitchcare, a measure of my desperation (sorry Dave).


References


Anon. (1983). Pests of Turf. Sports Turf Bulletin 140, 7-8. Anon. (1984). Leatherjackets. Ministry of Agriculture, Fisheries and Food Leaflet 179. pp 8. Atrick, G. (1994). Insecticides: an historical perspective. Groundsman 47 (1), 34. Blackshaw, R. P. (1991). Leatherjackets in grassland. Proceedings of the British GrasslandSociety Conference. Strategies for Weed, Disease and Pest Control in Grasland, 6.1-6.12.


Dawson, R. B. (1932). Leather jackets. Journal of the Board of Greenkeepers Research 2, 183- 195.


Drury, S. (1993). Worst of Pests. Turf Management May, 16-17. Edwards, C. A. & Bohlen, P. J. (1996). Biology and Ecology of Earthworms. Chapman & Hall, London, pp 426.


Evans, K. A. (1996). The control of leatherjackets in grassland using Bacillus thuringiensis. Proceedings Crop Protection in Northern Britain, 231-236. Lewis, G.C. & Vaughan, B. (1997). Evaluation of a fungal endophyte (Neotyphodium lolii) for control of leatherjackets (Tipula spp.) in perennial ryegrass. Annals Applied Biology 130 (supplement), 24- 35.


Mann, R. L. (2003). A survey to determine the spread and severity of pests and diseases on golf greens in the UK and Ireland. Journal of Turfgrass and Sports Surface Science, in press Peters, A. & Ehlers, R. U. (1994). Susceptibility of leatherjackets (Tipula paludosa and Tipula oleracea; Tipulidae; Nematocera) to the


Potter, D. A. (1998). Destructive Turfgrass Insects. Biology, Diagnosis and Control. Ann Arbor Press, Inc. Michigan, 117- 118.


entomophthogenic nematode Steinernema feltiae. Journal of Invertebrate Pathology 63, 163- 171.


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