THE SILVER Y MOTH. 15 



It is widespread in its localities ; it is to be found over the 

 northern half of the globe from Abyssinia to Greenland ; it is 

 said to extend to the frontiers of China and Siberia, and it is 

 also prevalent in North America. 



In 1735 the caterpillars did much damage to Peas and 

 Beans in market gardens round Paris ; in 1816 the moths 

 were noticed in vast numbers in the northern part of France. 

 In 1831 the caterpillars appeared in Bavaria, and in 1868 on 

 the Sugar Beet in Saxony ; and again in 1879 they appeared 

 in Saxony in such overwhelming numbers that it is shown 

 (from statements quoted in the ' Times ' of Nov. 12th, 1879, 

 p. 6, col. 1, of information given at the previous meeting of 

 the Society for the Promotion of Sugar Beet Industry at 

 Halle) that, " before the appearance of the moth and cater- 

 pillar, the Sugar Beet crops in Saxony were in excellent con- 

 dition, and would in ordinary circumstances have yielded a 

 harvest of from nine to ten tons per acre ; the actual yield, 

 where the caterpillars had been, was only three tons." 



The moths generally lay their eggs beneath the leaves " in 

 considerable clusters" (J. C), singly; hatching in ten to 

 fourteen days (E. L. T.) ; and although the caterpillars may 

 be seen feeding by day, they are not easily to be observed, 

 from their colour resembling the leaves. When full-grown 

 they are green, with a green or brownish head, narrow white 

 streaks along the back, and a yellow streak along each side ; 

 and are covered with short hairs. They have a pair of reddish 

 brown feet on each of the three segments behind the head, 

 but have only two pairs of sucker feet beneath the body, and 

 one pair at the tail, these are all green. When full-fed they 

 spin a woolly or silken cocoon in a leaf or on a stem, within 

 which they change to a pitch-coloured chrysalis. The moths 

 have the head, body between the wings, and crests running 

 along the back and abdomen, of a purplish brown or deep 

 ashy grey ; the fore wings, which have a satiny lustre, are 

 variously tinted with grey and brown, the distinguishing mark 

 being a bright white or yellow figure resembling the letter of 

 the Greek alphabet known as " Gamma " and the English 

 " Y," whence the name of " Gamma " or Y Moth. The 

 hinder wings are whitish, with dark veins, and a broad brown 

 maigin. The moths may be seen as early as April, but are 

 most common towards autumn. — ('Farm Insects,' 'Brit. 

 Moths,' ' Prak. Insecten-Kunde,' &c.) 



Prevention and Piemedies. — These caterpillars feed on 

 most of the low-growing plants, and also, if pressed for food, 

 on the grasses ; so that clearing weedy or grass-grown spots 

 in or round gardens is a good means of prevention ; nettles 



