80 [September, 



known in the island as the "black grub," and, as here, nipping off the 

 young plants just below the surface. Another is Prodenia retina, not 

 known in this country, but of very wide distribution ; it appears in 

 great numbers, and clears everything before it ; in December, 1876, 

 the Cricket Valley Crater was grown over with wild tomatoes, which 

 were covered with the caterpillars ; the tomatoes died off in April, 

 1877, and but few of the caterpillars were to be seen until last No- 

 vember, wheii they swarmed over the whole mountain. Another 

 caterpillar, which is said to be seen in numbers, is that of a Leiicania, 

 apparently L. Loreyi, but it is not stated upon what it feeds ; probably 

 grasses and cereals. Two pretty species of Plusia — P. aurifera and 

 (apparently) P. JJ-aureum — with characteristic " half-looper " larvae, 

 are said to be destructive to garden produce. The other moths are 

 CosmopTiila xantliindyma and a species of CaUopistria, but of these the 

 larvfe have not been observed. 



Naturally the islanders seek means of ridding themselves of this 

 plague of caterpillars ; but these are very difficult to suggest. The 

 introduction of rooks or starlings appears to be practically impossible, 

 on account of the treeless condition of the island. The sparrow 

 would, I think, be useless ; if introduced, it would sure to keep to the 

 houses, and moreover, the larva? are large, and, in the case of the Aqrotis, 

 only at work above ground during the night. I have suggested the 

 breeding of large numbers of ducks, if this can be done successfully 

 in an island with so little water, and, failing these, the turning out of 

 large flocks of fowls and guinea fowl, and building sheds for them in 

 which to shelter and roost. 



Strict attention to systematic alternation of crops is, I think, de- 

 sirable ; and not less so is the careful collection and destruction of all 

 larvsB and pupae turned up by the plough or spade. 



Chemical and other agents seem to be of little service ; but I 

 know that the sprinkling of unslaked lime over the plants has been 

 found useful in the case of Agrotis segetum. 



An estimate of the number of land birds on the island accompanies 

 the insects, from which it appears that there are about 25 pheasants, 

 400 partridges, 100 guinea-fowl, 1100 domestic fowls, 25 ducks, 50 

 canaries, 10 cardinal birds, and 1500 wax bills ; the guinea-fowl are 

 said to keep about the N. E. plains, 400 feet above the gardens, and 

 live on grasshoppers and crickets ; surely if these birds were pinioned 

 or prevented from straying, they would find the larvas equally to their 

 taste. 



The only immediate consolation I can give the unfortunate 

 islanders is, that destructive insects, as a rule, only appear in extra- 

 ordinary numbers in certain years. 



LewisliaDj, London : Avgnst, 1878. 



