12 



The Y. Moth. (Plusia Gamma.) 



(Pti.TE I. Fig. 2.) 



In some seasons the large prettily-marked caterpillars of this 

 moth appear in great numbers and clear off whole fields of clover 

 chiefly the second cuts. They also devour peas, rape, turnips, 

 and cabbage. According to Taschenberg and Hitzema Bos, they 

 attack sugar-beet plants in France and Germany, and Nordlinger 

 says that in France in 1735 they ruined the crops of peas, beans, 

 hemp, flax, and vegetables in wide-spreading districts. In 1828, 

 in parts of East Prussia, many fields of beans, peas, flax, cabbage, 

 and potatoes, were stripped of all but the stalks of the plants. 

 Most serious damage has been caused to sugar-beet in more recent 

 seasons in Saxony and other parts of Germany. In the summer 

 of 1879 there was a great invasion of this insect in the whole of 

 Western Europe, and much harm was caused to many crops. 



In 1881 these caterpillars were abundant in several parts of 

 Kent, and appeared again though in somewhat diminished 

 numbers in 1892. Complaints of much injury done by cater- 

 pillars to clover were received on July 8th 1892, from the neigh- 

 bourhood of Rochester, Kent. ' Again, on the 13th of July, 

 another correspondent wrote, "I send you some caterpillars. 

 This pest has eaten a piece of second-cut clover, near Gravesend, 

 40 acres in extent, till there is hardly a green leaf to be seen. 

 I notice they eat turnips, lettuces, thistles, when what appears 

 to be their natural food is finished, but they seem to favour 

 thistles, though I have found them eating potatoes. They have 

 now almost disappeared, having been eaten by rooks, starlings, 

 and other birds." 



Another observer, writing on the llth of July, from North 

 Kent, said : " When the clovers were cut, the fields were swarming 

 with caterpillars, which have eaten up the undergrowth so 

 completely that the fields are perfectly brown, and it is very 

 doubtful whether we shall get any second cut at all. They 

 have a'so invaded the cottage gardens adjoining." Upon the 

 18th of July a note was received from the same observer to the 

 effect that " the caterpillars have apparently left the clover fields, 

 or have been destroyed by the rooks and starlings. I am 

 afraid the cottage gardens, where the birds cannot get at them 

 so well, have suffered a good deal." 



Upon carefully examining these caterpillars it was found that 

 they had the appearance of Plusia gamma caterpillars, but 

 some were darker in colour than these usually are. There 

 were great differences, however, in their colour. 



