XVI. 
THE GENUS SILPHA, Linne* 
BY REV. W. F. JOHNSON, M.A., F.E.S., AND G. A. LEWCOCK. 
The members of this genus form one of the great sub-divisions of 
the tribe Silphina and belong to the sub-order Clavicornia. They 
differ from the genus Necrophonis in having eleven joints in their 
antennae, whereas the former, possess but ten. This difference, 
however, is more apparent than real, as a close examination of the 
Necrophonis antennae reveals an almost imperceptible second joint—it 
is perhaps more distinct in specimens of N. humatov and N . vespillo 
than in other members of the genus, although it varies considerably in 
these species. Apart from this distinction, however, the antennae 
gradually thicken towards the apex, but in Necrophonis they terminate 
with a strong four-jointed club. Then, again, in Silpha the head is 
extended into a long narrow neck, which is drawn up under the thorax 
when at rest. 
The life-history of many of the species is well-known, the 
majority being carion-feeders, but more investigation is needed with 
respect to others. The methods adopted by the Necrophori in burying 
their food have been so frequently dealt with that it is needless to 
attempt recapitulation. There is no doubt that in the first place the 
female beetle deposits eggs in the pabulum, but that the young larva 
is entirely reared on that food is very questionable, as anyone who has 
had experience of working this group must know. On a certain 
occasion one of us discovered a dead duck, and besides finding on it a 
hundred or more blisters, any quantity of Choleva chrysomeloides and 
other Cholevina, several Staphylinidae, &c., there were eight Silpha 
tlioracica , three or four Necrophonis mortuorum , some twenty N. humator, 
and no end of dipterous larvae. With such ravenous devourers as 
these, what chance would a beetle larva have to attain the full-fed 
stage, unless, like Rhipipliorus , it matured in 48 hours ; it is quite 
certain that it must make use of its legs, and move off in search of 
other food. This food must also vary : sometimes it may be decaying 
fungus, a caterpillar, snail, or decomposing vegetable matter. In the 
case of 5 . opaca the larva is said to attack beet, mangold-wurzel, and 
other root crops. Of this we have had no experience, although we 
have searched diligently for it in agricultural districts. The change 
to pupa takes place, as one might naturally expect, beneath the soil, 
and the beetle emerges in three or four weeks. 
The number of British species contained in Sharp’s 1871 Catalogue 
amounted to thirteen, and one var., Subrotundata. Fowler (1883) 
* Read at Meeting of City of London Entomological and Natural History Society, 
May 16, 1893. 
