36 REPORT ON INJURIOUS INSECTS FOR 1904. 



stones, clods of earth, etc. The pupa is a deep chestnut brown 

 colour, and is sometimes found in an earthern cell. The 

 second brood of moths appear in August. Most of the larvae 

 pupate in the autumn, but some may not do so until the 

 following spring. 



PREVENTIVE AND REMEDIAL MEASURES. 



On small areas much good may be done by hand picking 

 early in the year. 



Wherever an attack has been observed, the ground should 

 be well turned over in the winter and poultry turned on to the 

 land. 



Dusting with gas lime, which has been exp>osed to the air 

 for three or four months, is often recommended, but is far from 

 satisfactory, often spoiling such plants as cabbages for culinary 

 purposes. Watering with liquid farmyard manure, one part 

 to three parts of water has proved very beneficial . 



THE DOT MOTH. 



Mamestra persicariae, Linn. 



Some larvae sent by a correspondent in Warwickshire, that 

 were attacking ferns, were those of the well-known Dot Moth. In 

 this case they had eaten almost all the fern leaves and were 

 moving to large beds of Nasturtiums. When present in large 

 numbers they can do much damage, particularly so in flower 

 gardens, vegetables and fruit trees are also often attacked. 



LIFE-HISTORY. 



The moths made their appearance in June or July. The 

 female deposits from thirty to forty eggs on the food-plants 

 during July and August, the larvae from which , become full-fed 

 in four or five weeks and then measure about an inch and a half 

 in length. They are exceedingly variable in colour, such being 

 partly due to the food and partly protective. It is no uncommon 

 thing to find grey-coloured larvae on grey parts of a plant, brown 

 ones on brown parts and others of a deep green colour on deep 

 green leaves. 



The mature larvae fall to the ground, changing to deep 

 brown pupae in the earth beneath the food-plant, where they 

 remain until the following year. 



PREVENTIVE AND REMEDIAL MEASURES. 



Where they are not spread over a large area hand-picking 

 soon reduces their numbers. In vegetable gardens I have found 

 that large numbers may be destroyed by watering with a hose 

 and a good force of water. 



In the autumn, ground known to be infested with the pupae 

 should be lightly forked, and ducks or fowls allowed to run 

 over. 



