EXPEDITION AIMS/ISLANDS SAMPLED
The aim of the expedition was to investigate the influence of artifical light sources on the immigration rate of moth species to small tropical islands. With this in mind twelve of the Grenadines - four uninhabited and without artificial light (Baliceaux; Battowia; Isle a Quatre and Frigate Is.) and eight inhabited and with artificial light (Bequia; Union; Canouan; Mustique; Mayero; Petite Martinique; Palm Is. and Petit St. Vincent) were sampled for moths using a 'Robinson' pattern Mercury Vapour trap powered by a Honda EG 550 portable electrical generator. Butterflies and beetles were also collected. although these are not considered here. Sampling period varied with size of island and varied from 2 days on the smallest islands to 16 on the largest.
The data collected - as reported in the Expedition's unpublished report - suggest a significant correlation between island size and number of species, as predicted by classical island biogeography. However, no correlation could be shown between presence of artificial lights and increase in number of species.
The expedition was highly successful in one particular respect, namely the making of a large, systematic collection of moths from a hitherto poorly-sampled area of the world. This collection, stored in six 30 x 43 cm wooden double-sided storeboxes (plus three further similar storeboxes of butterflies) was kindly made available to me by Dr. David Stradling in 1998 and, since Dr. Stradling's recent retirement, has been transferred to me on permanent loan.
Regrettably - and unsurprisingly - the students on the 1984/85 expedition were inexperienced in field collection and storage techniques and not familiar with the taxonomy of Caribbean moths. As a result much of the material is in very poor condition (although fairly well-preserved from the subsequent ravages of museum pests). Although the Expedition were able to identify all of their butterfly captures, the vast majority of their moth captures remained unidentified (or misidentified) in the collection until I was able to start work on it some 13 years after the event.
IDENTIFICATION OF SPECIMENS
Specimens were identified on the expedition by serial numbers ranging from 1 to 246 as they were captured, and in the pinned collection now in my care the majority of the specimens have scraps of paper beneath them bearing this number (no other data labels are present). Regrettably, as more material was collected by the Expedition it became clear to them that the same species had been assigned several different numbers, and also that the same number had been assigned on many occasions to mixed series of several species. This, together with labels being totally missing on some specimens, and some numbers apparently not being used at all, has made piecing together data from the collection somewhat of a 'Chinese Puzzle'. Dr. Stradling has kindly loaned me the expedition's field-notes, noting which 'serial numbers' were collected on which islands, and this has helped to make sense of the data. By constructing a table of 'island name' vs. 'serial number' it has been possible to reconstruct the distribution of MOST species, but a significant proportion of the records are still muddled and will remain so. It is also clear (from identifications of species made in the Expedition report that are not present in the collection I received) that some of the 'better' specimens have been dispersed elesewhere - possibly to the collections of the Natural History Museum in London, who helped with initial determinations. In such cases, where the identification appears likely to be correct from my own work in the Eastern Caribbean, I have taken this record on trust. Obvious misidentifications have been noted.