232 AFFECTION OF INSECTS FOR THEIR YOUNG. 



different species of this tribe being appointed to prey upon and thus keep 

 within due limits the larvae of different kinds of insects, will be a sufficient 

 answer. But one circumstance creditable to the talents of the mason- 

 wasp as a skilful purveyor should not be omitted, namely, that the number 

 of grubs laid up is not always the same, but is exactly proportioned to 

 their size, eleven or twelve being stored when they are small, but only 

 eight or nine when larger. With respect however to the caution of the 

 wasp in selecting full-grown grubs and conveying them uninjured to her 

 hole, a satisfactory explanation may be given. If those that are but 

 partly grown were chosen, they would die in a short time for want of food, 

 and putrefying would destroy the enclosed egg, or the young one which 

 springs from it. But when larvae of any kind have attained their full 

 size, and are about to pass into the pupa state, they can exist for a long 

 period without any further supply. By selecting these, therefore, and 

 placing them uninjured in the hole, however long the interval before the 

 egg hatches, the disclosed larva is sure of a sufficiency of fresh and whole- 

 some nutriment. — To prevent the possibility of any injury to its egg from 

 the motions or voracity of this living prey, the wasp is careful to pack the 

 whole so closely, each grub being coiled above the other in a series of 

 rings, and to consolidate the earth so firmly above them, that they have 

 not the slightest power of motion.^ — Those which select more powerful 

 caterpillars, or revenge the injuries of their insect brethren by devoting 

 spiders to the destruction they have so often caused, take care to sting 

 them in such a manner as, without killing them outright, will incapacitate 

 them from doing any injury. 



Zeal and activity in providing for the well-being of their future progeny, 

 not inferior to what are exhibited by the tribe of Ichneumons, Sphecina^, 

 and mason-wasps, though less cruelly exerted, are also shown .by various 

 species of wild bees, of which we have in this country a great number. 

 Having first excavated a proper cell with a dexterity and persevering 

 labor never enough to be admired, they next deposit in it an egg, which 

 they cover with a mass of pollen or honey collected with unwearied assid- 

 uity from a thousand flowers. As soon as the grub is hatched, it finds itself 

 enveloped in this delicious banquet provided for it by the cares of a 

 mother it is doomed never to behold ; and so accurately is the repast 

 proportioned to its appetite and its wants, that as soon as the whole is con- 

 sumed it has no longer need of food ; it clothes itself in a silken cocoon, 

 becomes a pupa, and after a deep sleep of a few days bursts from its cell 

 an active bee. 



A considerable number of wild bees, however (those of the genera 

 Nornnda, Melecta, &c.) being unprovided with an apparatus for collecting 

 pollen, save themselves not only this labor but also that of excavating 

 cells, and gliding into those in which their more industrious brethren have 

 deposited their eggs and the necessary supply of pollen moistened with 

 honey for food, they also, cuckoo-like, insinuate their own eggs, (imitating 

 in this respect the carnivorous parasites lately noticed,) the larvae from 

 which live at the cost of the rightful occupants. 



1 Reaum. vi. 252. 



* By this term I would distinguish the tribe of Fossores of Latreille, which the French 

 call Wasp- Ichneumons, and which form the Linnean genus Sphex, divisible into several 

 families as> Sphecidee, PompilidcBy BembecidcB, ice. 



