FOSSORIAL HYMENOPTERA 
443 
living underground. Scoliids may constantly be seen quar- 
tering the ground, and sometimes may be found scratching 
at the earth, presumably to enable them to reach the sub- 
terranean prey which is stung, and has an egg laid upon it. 
There is no laborious excavating a burrow and dragging a 
heavy burden thereto : the prey is simply rendered inert 
and left where it is. 
Another family of Eossors, the Mutillidce , has improved 
upon even this method. Like the man in the parable, they 
cannot dig, but then they do not need to ; for their prey 
is usually 1 the larvae of other Hymenojptera, whose nests are 
often freely exposed — such as those made by ‘ mud-wasps.’ 
All they have to do, when a nest has been found, is to lay 
an egg upon the larva inside, penetrating the wall with the 
ovipositor. I am not certain whether these Fossors sting 
the prey so as to paralyse it ; they possess very sharp and 
painful stings — as one soon finds out by picking them up in 
one’s fingers. 
The Mutillidce are rather peculiar in that the females have 
no wings and are easily mistaken for ants. Their colouring, 
however, distinguishes them ; they are black and red, or 
black only, with conspicuous large white spots. They 
particularly frequent rather dry open country, and may be 
seen running quickly over hot sand. Fossors, then, have 
evolved a unique method of ensuring a supply of fresh juicy 
meat to their young. But another of the great divisions of the 
Hymeno'ptera have altogether dispensed with a sting : these 
are the ‘ ichneumon flies,’ called accursed by the mere collector 
of butterflies and moths, who is only interested in breeding 
a perfect specimen for show purposes, having obtained an 
egg, caterpillar, or chrysalis. Instead of the expected beauty, 
however, he only breeds a host of little beasts ! These have 
come from eggs deposited by the parent ichneumon on the 
immature stage of the host. The ichneumon larva at first 
feeds only on the unessential fats and juices ; so that if the 
prey is a caterpillar, it continues to feed and grow, and often 
even has strength to become a chrysalis, after which the 
1 Some species, however, have been found to prey upon Glossina morsitans 
in its pupal stage. 
GG 
