Reports to the Board of A griculture. 139 
Beetles ( Pterostichus madidus ) damaging Mangold. 
The beetles damaging mangolds sent by a correspondent were one 
of the ground beetles or Carabidse, called Pterostichus madidus, in 
some works Steropus madidus. It is well known as a mangold 
pest. 
The ground beetles were at one time thought to be only carnivorous, 
and, therefore, beneficial. Although the majority are carnivorous we 
now know certain species are very destructive. Three at least, 
besides the one mentioned here, do a great deal of harm to straw- 
berries. Steropus madidus, besides attacking mangold and straw- 
berries, is also found eating swedes and kohl-rabi. 
Miss Ormerod records this species as damaging mangolds as 
follows : “ Steropus beetles were forwarded, which had been caught 
also early in the morning in the act of eating mangolds. The injury 
was just at the ground level, sometimes all round, what may be 
termed the shoulders of the root. The beetles did not eat the leaves 
and the damage was noticed as being done in the very early morning, 
or, in fact, almost in the night.” 
They usually attack plants just under the ground or level with it 
generally where the root begins. The whole root may be eaten right 
away or may be only partly damaged, as the one sent. When pieces 
only are eaten out of the root the plant never properly develops ; 
deformed and stunted wurzel result. 
The leaves never seem to be harmed. Like most Carabidse, this 
pest works almost entirely at night and hides away during the day. 
One favourite hiding-place is under stones. Several attacks have 
been noticed in fields where flints are abundant. Curtis records this 
beetle as attacking and feeding upon Wireworm. 
As far as is known, the female lays her eggs either in the earth 
or under stones. The larvae hatch from the eggs in eight days and 
appear to be solely carnivorous. They are dark brown with large head 
and jaws and six jointed-legs in front ; when mature they are about 
two-thirds of an inch long ; the end of the body has two long bristly 
processes. When mature they pupate in the ground and remain as 
pupae during the winter months. The beetle is common generally 
in Great Britain, and also occurs in Germany, Belgium, France and 
Switzerland. 
Prevention and Remedies. 
After an attack of this pest, land should be deeply ploughed and 
wurzel should not be grown in neighbouring fields when it is possible to 
