INTERRELATIONS OF INSECTS 315 
ously a ball of dung which is to serve as larval food. The 
female mole-cricket (Gryllotalpa) is said to care for her eggs 
and even to feed the young at first. 
Hymenoptera display all degrees of complexity in regard to 
maternal provision. Tenthredinidz simply lay their eggs on 
the proper food plants or else insert them into the tissues of 
the plants. Sphecina make a nest, provision it with food and 
leave the young to care for themselves. Queen wasps and 
bumble bees go a step further in feeding the first larvee and 
carrying them to maturity. Finally, in the honey bee the care 
of the young is at once relegated by the queen to other individ- 
uals of the colony, as is also the case among ants. 
Some of the most elaborate examples of purely maternal 
provision are found among the digger wasps and the solitary 
wasps; these instances are highly interesting, involving as ‘they 
do an intricate co-ordination of many reflex actions—as ap- 
pears in the discussion of insect behavior. 
Among the Sphecina, or digger wasps, the female makes a 
nest by burrowing into the ground, by mining into such pithy 
plants as elder or sumach, or else by plastering bits of mud 
together. The nest is provisioned with insects or spiders 
which have been stung in such a way as usually to be para- 
lyzed, without being actually killed. The various species of 
Sphecina frequently select particular species of insects or 
spiders as food for the young. Pepsis formosa (Pompilide ) 
uses tarantulas for this purpose; Sphecius speciosus ( Bembe- 
cide) stores her nest with a cicada; Nyssonidz pick out cer- 
tain species of Membracide; mud-daubers (Sphecide) use 
spiders; and other families of Sphecina capture bees, beetles, 
plant lice or other insects, as the case may be. The solitary 
wasps (Eumenidz) are similar to the digger wasps in habits. 
Of the solitary bees, Wegachile is well known for its habit 
of cutting pieces out of rose leaves; it uses oblong pieces to 
form a thimble-shaped tube which, after being stored with pol- 
len and nectar, is plugged with a circular piece of leaf. The 
larval cells are made either in tunnels excavated in wood by 
the mother or else in cracks or other chance cavities. 
