462 



Large White Butterfly. 



and other buildings, and the sides of banks, rocks, and cliffs. 

 The pupa or chrysalis is slightly more than an inch long. It 

 is usually pale green in colour, with very small black dots all 

 over it. Sometimes it is bluish green, shaded with yellow. 

 The pupal state continues for about thirteen days. 



The butterflies of the second generation lay their eggs in the 

 first weeks of July, when there is a wide choice of cultivated 

 cruciferous plants in the field and garden. From these eggs 

 the caterpillars are hatched in seven or eight days, and 

 their depredations may be most serious if the climatic condi- 

 tions are favourable. When the caterpillars are full fed in 

 ordinary seasons they crawl away and become chrysalids in 

 the situations already described, where they remain until the 

 following spring. As has been stated above, a third brood 

 of butterflies is sometimes produced in favourable circum- 

 stances, but this is exceptional. 



Modes of Preventioji and Remedies. 



If careful attention is given in June to plants infested with 

 these caterpillars a much more serious attack may be pre- 

 vented from the succeeding generations. Most of the culti- 

 vated plants of the Brassica group are then small, and may 

 be hand-picked in market gardens, gardens, and allotments, 

 or syringed with water, or dusted with lime and soot. In 

 fields, they may be dusted with lime and soot by means of a 

 horse distributor. The outsides of fields near infested crops 

 should be kept clear of weeds. In market gardens, gardens, 

 or allotments, the woodwork of open lodges, sheds, and other 

 outbuildings should b^ brushed down and the walls well lime- 

 washed in order to dislodge the chrysalids. Dusting infested 

 plants with lime and soot is a good remedy. The mixture 

 should be composed of three bushels of lime and one of soot,, 

 very finely powdered, and applied with a hand-dusting 

 machine in gardens and allotments, and a distributor in 

 market gardens and fields. Distributing by hand would 

 serve in gardens, allotments, and small patches of plants. 

 Hedge-rows and the sides of hedges should be brushed in 

 the winter and the rubbish burned. 



In America attacks of a similar butterfly are successfully 



