Jan., '09] ENTOMOLOGICAL NEWS. 5 



their anal spiracles to the surface of the mass. This was 

 usually done within twenty- four hours, and those larvae, unable 

 to work their way to the surface, eventually perished. Sev- 

 eral mounted in Canada balsam lived in that medium for over 

 a week, but their anal spiracles were exposed at the edge of 

 the coverglass. It is evident that the larva must come to the 

 surface for air, though this may be only at long intervals. 

 It was difficult to observe the way in which the larva gets its 

 air supply under natural conditions, owing to the opaqueness 

 of the resin, but investigation showed that the insect always 

 had its anal spiracles towards the surface of the nodule, at 

 times in a hollow in the pitchy mass, and in other cases so 

 deeply submerged in the medium that it seemed doubtful if the 

 insect could extrude its terminal spiracles. A rule apparently 

 quite constant was that soft resin harbored large larvae, while 

 in the harder, often discolored medium these insects were short- 

 ened and of a reddish color, as if preparing for pupation. A 

 lump of soft resin if hardened would always stunt the larvae 

 within. These would often pupate, but without forming a 

 cocoon. 



Pupation does not occur until spring, and is probably de- 

 pendent upon temperature. During winter many larvae 

 formed pupal chambers and lay therein as abbreviated reddish 

 prepupae. A note dated January i8th, 1908, states that fresh, 

 soft resin harbored feeding larvae, while hard, crusted resin 

 contained larvae in their pupal chambers, the latter being the 

 more numerous. Another note of January i/th states that 

 many larvae were observed still feeding, and that the shortened 

 ones are to be found in the harder gum, reddened perhaps by 

 excrement. 



Before transforming the larva makes a cocoon of thin 

 papery consistency, a good deal longer than the prospective 

 pupa and with one end bulging from the resinous mass as a 

 cap. A number of cocoons may be found in close proximity, 

 so that their walls touch. In such cases they resemble some- 

 what the miniature comb of a social wasp. Whether the 

 cocoon is spun by the larva was not determined ; I am inclined 



