Mercury-vapour [m/v] lamps have been utilised in various ways, as bulbs attached to transformers 

 on long leads for usage in gardens, or associated with simple traps set into windows of a room, or else in the 

 conventional format of enclosed Robinson light-traps. These light-traps were either operated from the mains 

 electricity supply or from portable power-driven generators for external usage at chosen sites and were in 

 constant action during the 1960s. First mention of usage was by M.L. & R. Long & J.H. Richards in Jersey, 

 commencing in 1960. It was not until the summer of 1966 that this type of m/v light-trap came into regular 

 use in Guernsey. From 1960 onwards, at least in Jersey, it was certainly used consistently as an aid in 

 sampling nocturnal moths. This began an even more earnest effort to help record Lepidoptera, generally 

 acknowledged to be a much neglected group, most especially the many species of microlepidoptera. The 

 Jersey Lepidoptera listed by R. Dobson, from the 1960 records compiled by M.L. & R. Long & J.H. 

 Richards (1961: 21-27), amply showed that many specimens could be captured on a given night, allowing a 

 larger amount of material to be sampled over a long period. In 1967 C.J. Shayer (1967: 26-27) reported on 

 the 1966 Guernsey records and noted that nearly 700 larger moths were trapped during that summer season. 

 The trapping provided useful information on population figures for numbers of common species. 

 Surprisingly though, the total catch comprised only 60 species. Shayer did not state how many specimens 

 and species of microlepidoptera were recorded, but the numbers were assuredly larger than those from any 

 previous individual year. On Sark, it is the author's experience that around 200 species can be found during 

 a summer period of two weeks. This sort of figure is obtainable without resorting to trapping, but by 

 monitoring at night m/v light-sources over a white sheet and combining this work with daytime 

 observations. However, as expected, light-traps used in both of the Bailiwick's for attracting and sampling 

 moths, continually revealed an increase in numbers of species for most families and in consequence, the 

 discovery of previously unrecorded species. In 1970 a portable m/v light-trap was used for the first time in 

 Alderney by R. & M.L. Long and V. Mendham, with extensive results published by the Societe Guernesiaise 

 in 1971. The same light-trap started its usage in Jersey in 1970, with the first results published in the Societe 

 Jersiaise in 1971. From 1971, a light-trap has been used throughout the year at the established Rothamsted 

 Experimental Station in St. Martin, Guernsey, with records passed on to the current recorder at the Societe 

 Guernesiaise. Largely due to the constant use of m/v light-traps, hardly a year has passed since 1960, 

 without some previously unrecorded species being added to the island's fauna. 



By the late 1980s, there was an increase of interest shown in the Channel Islands fauna from 

 mainland English entomologists, both amateur and professional. This included the Biological Records 

 Centre at Monks Wood Experimental Centre. The desire was also to include the Channel Islands within 

 the provisional distribution maps formulated by John Heath. In consequence, since the first volumes issued 

 in 1983 of the series The moths and butterflies of Great Britain and Ireland, edited by John Heath, the 

 Channel Islands were incorporated on the mapping scheme as Vice-county 1 13. At this time, the Rothamsted 

 Insect Survey teams had established permanent light-traps in both Jersey and Guernsey that are run 

 throughout the year. Since then, the usage of m/v light-traps has become ever more prevalent. Especially in 

 recent years, sampling was also underway from privately owned light-traps almost throughout the year on 

 the larger islands of Guernsey and Jersey. Furthermore, almost annually, short visits by the resident Jersey 

 recorders R. & M.L. Long, to the three small islands of Alderney, Sark and sometimes Herm, are used for 

 light-trapping moths. Now, many records from what were neglected islands are becoming available. Besides 

 the more standard forms of light-trap, usages of actinic or black lights were in operation in the late 1980s, at 

 least in Guernsey. 



Often it would seem light-traps in use in the Channel Islands are left on all night, unmonitored. 

 Alternatively, to obtain quick sampling, the traps are lit for short periods, and monitored. Today, with the 

 amount of collecting undertaken all over the world, often in difficult, if not hazardous terrains, light-traps 

 plus many other techniques, are ideal for the occasion. On such foreign trips, the major considerations may 

 be the necessity to collect the specimens in good condition and as much as is practical, within a limited 

 amount of time, for the occasion may not be repeatable. Under Western European conditions these factors 

 are not paramount. Nevertheless, for Lepidoptera, even in tropical conditions, m/v light sources combined 

 with white sheet surfaces enable the collector to be selective over the material retained, without the risk of 

 damaging or killing off excess numbers of specimens. This ensures the obtaining of a collection of the 

 highest possible quality, including the larger macrolepidoptera and material of smaller microlepidoptera. 

 Immediate pinning and sometimes even setting in the field of all specimens, most especially the micro- 

 pinning and wing-spreading of all small specimens, will ensure that the material brought back is in perfect 

 condition. Light-traps have their advantages when used for random sampling periods. This serves both the 

 collector and other disciplines in field Entomology, particularly for agricultural entomologists when 

 sampling pest species and analysing population densities. 



Indiscriminate use of light-traps by collectors, or for monitoring purposes can have disadvantages. 

 In either case, when light-traps are left unmonitored, the disadvantage of the larger and more active 

 specimens damaging the smaller material will be an ever present risk. Not all collectors are necessarily 



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