Reports to variotis Correspondents. 71 
The eggs are very minute, oval, white, with an inegular ridged 
appearance ; they hatch out in about a week, some as soon as lour 
days. Taschenberg states that they take as long as ten days. The 
maggots which work on and in the roots as previously described are 
dirty white in colour, fleshy and footless as in all Diptcm, the 
segments are provided with rows of minute tubercles by means ol 
which the maggots move; the head end is pointed and provided 
with two mouth hooks ; the anal end is truncated with ten conical 
processes, the two ventral central ones being bifid when the grub is 
full grown, a character which scarcely shows in a young larva; in 
the centre of this truncated area are the two spiracles, each composed 
of a brown area with three narrow curved slits ; on each side of the 
third segment is a fan-shaped spiracle with twelve lobes, which 
appears to be functionless. When full grown the larva is the fourth 
of an inch long. This period lasts about three weeks : Slingerland 
says less than three weeks ; Whitehead, twenty -four to twenty-eight 
days ; Bouche from three to four weeks ; Carpenter, three weeks ; all 
those I have kept matured within a day or so of the latter date, 
most in twenty-one days. 
As soon as the maggots are mature they leave the roots and enter 
the soil, and there at a depth of from two to three inches the larval 
skin hardens and forms a case or puparium (Fig. 9, b) in which the 
pupal condition is passed. They do not all, however, enter the earth, 
some pupate in the stems of the cabbages. 
This puparium is at first much the same colour as the larva, but 
soon turns brown ; it is barrel-shaped in form with two prominent 
processes in front, the front spiracles are present seen in the maggot 
and traces of the two bifid spines behind. This stage lasts from two 
to three weeks in summer, whilst in winter it may last from October 
to April. There is often to be noticed great variation in size in these 
puparia. Under favourable circumstances this pest may continue 
to work all the year round, for Dr. Carpenter records the presence 
of maggots in the North of Ireland in January. 
The majority of maggots are mature by November, according to 
my observation, and have entered the puparium stage in which they 
pass the winter either in the ground or in the cabbage stalks. In 
some cases it also seems probable that some of the adult flies 
hibernate, so that we have this pest passing the winter in three 
different ways ; but I am not aware of any authentic record of the 
adult hibernating. 
