144 ZOOLOGY. 



similar markings. Hind wings in the male, bright 

 grey to snowy white ; in the female, brownish grey. 

 Caterpillar (Fig. 99) : ,Up to two inches, earthy grey, 

 occasionally somewhat greenish. Head and pro- 

 thorax darker. The time taken by the caterpillars to 

 complete their development differs according to the 

 plants attacked, and it is therefore easy to understand 

 why the moths should be seen flying about from the 

 first half of May right on into the autumn, without 

 having recourse to the improbable hypothesis of two 

 successive generations. The eggs are consequently 

 laid at very difierent times, and are always deposited 

 singly in the soil in the neighbourhood of plant roots, 

 or else in the low-lying leaves and stems of various 

 herbs. The caterpillars hatched from these are de- 

 structive earlier or later, according to the time of egg- 

 laying. Most specimens are half grown in winter; 

 these continue their destructive work the following 

 spring. In autumn they attack the roots of winter 

 grain (rye and wheat), rape, and species of cabbage ; 

 they also bore readily into turnips and potatoes. In 

 spring, after the winter rest, they continue to attack 

 the roots of winter grain, winter rape, etc., or fleshy 

 underground parts (turnips, potatoes) developed in the 

 interim, or the roots of summer plants (summer grain, 

 buckwheat, summer rape, vegetables, etc.). On clear 

 days the caterpillars always remain hidden in the 

 soil ; and those which have bored into juicy under- 

 ground parts of plants (turnips, carrots), do not leave 

 their abode during the day, but the others, both during 

 the night and on cloudy days, come above ground to 

 attack the leaves and stems of young plants. In ex- 

 ceptional cases the caterpillar is mature by the begin- 

 ning of winter, in which case it hybernates in the 

 soil as a brown pupa. The moths escaping from such 

 pupsB naturally appear earlier than others. As a rule, 

 the caterpillars do most damage to the winter crop in 

 autumn, wandering about a great deal ; in many cases 



