I 1 YMEN 0 P TER A. 
645 
As a rule, each species provisions its nest with a particular 
«rfnd of food. Some use only spiders for this purpose, some 
plant-lice, some caterpillars ; and so on through the list. 
Very interesting and useful work can be done by the 
student in the study of the habits of the digger-wasps and 
of the solitary true wasps and solitary bees. Comparatively 
few nests of either of these groups of insects have been 
carefully described in this country; and as each species 
presents peculiarities of habits, the study is a very fascinat¬ 
ing one. 
The nests are most abundant in sandy banks and in the 
pith of sumach, elder, brambles, and other plants. Some 
nests are dug in the earth in level places, and many are built 
of mud and attached to the lower surface of stones or be¬ 
neath the roofs of buildings. 
The nests made of mud should be carefully removed so 
as not to break them, the nature of the provisions noted, 
and the nest placed in a cage to breed the adult. When 
the adult has been obtained, both nest and insect should be 
mounted and placed in a collection. 
In many cases the cells of mining species can be re¬ 
moved from the earth and the insects bred in a similar way. 
But the easiest nests to study are those made in the pith of 
plants. If dead branches of sumach or elder be split open 
many of these insects can be found. If the branch be split 
carefully the peculiarities of the nest can be observed with¬ 
out injury to its occupants. Then if the pieces of the branch 
be tied together the adult insects can be bred by placing the 
nest in a glass jar or other cage, or in a bag of muslin, if the 
branch is a long one. 
If a nest is provisioned with a paste made of pollen and 
nectar, it is a nest of a bee; but if it is provisioned with 
spiders or insects, it belongs either to a digger-wasp or to a 
solitary true wasp. We know of no way of distinguishing 
between the nests of the last two except by breeding the 
adults. 
