6 
First Report on Economic Zoology. 
HOOT CROP PESTS. 
Silplia rug o set, L., on Turnips, and other Silphidce-. 
One of the Carrion Beetles, Silplia rugosa, L., closely related to 
the Beet Carrion Beetles ( Silplia opaca and S. cctrata), sent to the 
Board, was appearing in great numbers on a turnip crop. Both of 
the latter species are injurious to mangolds, the larvae devour the 
leaves and stem and often destroy a crop entirely. Silplia rugosa 
occurs with them nearly always and is probably the commonest 
member of the genus, being found almost everywhere, but there have 
been no observations made on this species showing that it does any 
harm to crops, such as occurs with the two closely related Carrion 
Beetles. 
The larvae of the Silpliidae and also the adults are normally 
carrion feeders. Numbers of these three species may usually Be 
found in June in and under any dead carcase laying about in the 
fields, but as previously stated the two species S. opaca and S. atrata 
frequently give up their carnivorous habits and attack mangolds and 
beetroots. Canon Fowler also records finding the larvae of a member 
of this genus on the roots of plants in the Isle of Wight. It is, 
therefore, possible that S. rugosa may sometimes become vegetarian 
in habit, but no mention has been made of this, nor does the Board 
correspondent make any such statement. 
The larvae of S. rugosa are moderately broad with the edges of the 
thoracic (i.e. first three) segments rounded, those of the remaining 
segments projecting. The body ends in two processes called cerci, 
which in this species are long, at least three times as long as the 
anal process between them ; the head is large and projecting. 
When full grown, which is usually by the middle, but sometimes 
not until the end, of July, they bury themselves in the soil to a 
depth of from three to four inches and turn to pupa?. 
After from three to four weeks beetles appear from these pupae, 
and these beetles apparently live through the winter. 
Miss Ormerod records the Beet Carrion Beetle (S. opaca) on 
potato and also as devouring the Spurrey ( Spcrgula arvensis), and 
it is thus possible that we may get S. rugosa working in a similar 
manner on various plants and not on any one in particular. 
As there is a possibility of these carrion beetles becoming 
destructive, steps should be taken to have the turnip and other fields 
cleared of them and any of their larvae. To do this is a compara- 
tively easy matter if we employ natural traps in the form of dead 
