but cane quickly soured and nearly always gave rise to mites, so 

 that use of corn was preferable. 



Movements of the grul) in a can have a tendency to pack the 

 earth, so that by careful manipulation of a knife lilade the top earth 

 may be removed and the grul)"s tunnel exposed. A tunnel averages 

 three to four times the length of the grub's body; and when one 

 part of the tunnel is opened the grub rushes to tl)e other extremity, 

 so that there is small danger of injury. The grub may thus be 

 viewed without disturbing it to any great extent. 



When a grub is first added to a can, the latter is filled even 

 full witli sifted fnot too fine) moist earth, and with the thumb 

 or finger a pit is compressed in the soil, into which the grub is 

 placed. It is never covered with earth. 



There is little to be improved upon in the matter of convenience 

 in the methods described here, provided care is taken ; nor is there 

 any more divergence from natural, outdoor conditions than would 

 be the case in using larger boxes, jars, or pots. Check experiments 

 proved that there Avas no difference in the time of emergence be- 

 tween adults from grubs in tin boxes and adults from grubs out- 

 doors, provided a grub escaped the attack of mites, fungus, or bac- 

 terial disease. The presence of these diseases in small boxes was 

 in most cases induced by over feeding, excessive moisture, or care- 

 less handling. 



Check experiments for each species were run in large outdoor 

 rearing cages, containing a depth of six to ten inches of earth in 

 which was grown cane or corn as food. Cages were of uniform 

 size, three by six feet and three feet high, screen covered with wooden 

 bottoms, set up on posts as protection from ants and rodents. Adults 

 were usually liberated in them in quantit}', one species in each, at 

 about the same time that other series were confined in jai's for eggs. 

 After a week or so of confinement adults were removed, eggs having 

 been deposited in the soil. The cage remained undisturbed, except 

 to be regularly watered and occasionally replanted to fresh cMue or 

 corn, until sufficient time had elapsed for gi-ulis to mnture and adults 

 to issue. 



In these cages the time recpiired for emergence tallied very closely 

 with the time required for grubs confined in tin boxes, showing that 

 soil conditions in the smaller tin boxes did not change the time of 

 emergence from normal. 



In the case of one species, Phytalus insularis, no larvse reared in tin 

 boxes were successfully brought to maturity, so that results obtained 



62 



