NOTES AND QUERIES. 335 



Most larvse were observed upon diseased larches ; in some cases 

 these trees were dreadfully infested, as . many as two and three 

 caterpillars being upon each bunch of needles. The trees in 

 great part recovered from these attacks by the production of new 

 needles arising amongst the eaten ones. The outer and first- 

 formed needles of sickly trees were shortened to the extent of one- 

 third of their length, but the total diminution through damage to 

 growth is placed at not more than one-sixth in normal circum- 

 stances, and only one-twentieth where the jDlants are growing very 

 strongly, and therefore are better able to repair the mischief done. 



The larvse of the mining moth always envelops itself in a 

 sheath made by hollowing out a larch needle. It never leaves 

 this cover, but drags it about with it, hibernates and pupates in 

 it ; at most its head and prologs are protruded from it. As the 

 larva grows larger it requires more accommodation, and obtains 

 this by attaching a second empty needle to the first by cutting 

 the sides away from both. Inquiry into the formation of this 

 curious dwelling was conducted as follows : — The cases were 

 removed from a number of larvee, which were then placed, one 

 lot among whole needles and another among needles that had 

 been cut into small pieces. The former set of caterpillars at once 

 constructed new cases, but the latter were unable to do this, only 

 sheltered under the heap of chips and did not thrive. 



Placed upon needles of the Siberian larch, the larvae at first 

 appeared unwilling to eat. They wandered restlessly to and fro, 

 but finally partook of the new fare and seemed well pleased with 

 it. For two or three days they ate voraciously, after which 

 sickness seized them, their excrement clung to their bodies, and 

 they were gradually covered with an unhealthy, yellow-green 

 crust. They stopped feeding, movements became weaker, then, 

 gathering their whole strength, they with difficulty broke open 

 their cases. No attempt to eat fresh needles was evinced, and 

 they died. A week later the experiment was repeated with a 

 similar result. 



It would therefore appear that Larix sibirica does not form 

 suitable food for the larvse, and that the female moth will 

 probably not lay her eggs upon it. But this finding should be 

 accepted with reserve, as the trial was conducted under quite 

 artificial conditions. 



With the Japanese larch a contrary result was obtained. As 

 soon as the needles were fully developed the caterpillars burrowed 



