156 Second Report on Economic Zoology . 
away from the roots of garden plants for a time. They may he 
collected in numbers by placing pieces of scooped out mangels just 
under the ground near the plants they are attacking. They swarm 
over the baits, and may then be collected and destroyed. Another 
certain way of killing them is by injecting bisulphide of carbon into 
the soil. They may also be trapped by soaking leaves of cabbage in 
Paris green and putting them about gardens. The Millipedes feed 
upon the green stuff and either get poisoned or can be collected. 
The Dot Moth. 
(Mamestrct persicarim, Linn.) 
Caterpillars of the Dot Moth, which were causing damage in 
London gardens, were sent to the Board by Mr. W. C. Barnard. 
The Dot Moth caterpillars are very frequently recorded as pests. 
Their food-plants vary much ; as a rule garden flowers, such as 
dahlias, marguerites, marigolds, pansies, geums, etc., suffer most ; 
vegetables are also eaten by these larvie, including cabbages of all 
kinds, lettuce, mint, parsley ; fruit trees and bushes are also attacked ; 
there are numerous accounts of their feeding on gooseberry and now 
and again on apple, plum, raspberry, currant. Other plants upon 
which they feed are lilac, poplar, clematis, ivy, etc. 
They are ravenous feeders, stripping the plants in a very short time. 
This insect is found all over Great Britain and in most parts of 
Europe. 
The caterpillars are subject to great variation in colour, apparently 
influenced to some extent by their food-plant, the colouring rendering 
them often extremely difficult to find when at rest upon their food- 
plant. 
Life-history. 
The moth appears in June and July. In size it varies from an 
inch and a half to an inch and three-quarters ; the front wings are 
blackish (with a dull purplish gloss when fresh) marked with rusty 
brown marks, with small pale spots at the tips and the hindermost 
edge, often, however, indistinct and with a large white kidney- 
shaped dot, often very pronounced ; the hind wings are dusky-grey 
shading into dull whitish at the base. They fly at night and 
deposit their eggs upon the food-plants ; as many as thirty are laid 
by each female. The larvae appear from the beginning of July, 
until the latter part of August, the last hatched ones not maturing 
until the end of September, and some even being found as late as 
