I'rdceedincs, \u-i'.'> 175 



Were u'f t(i rxiiosc tlic stork to a cyMniilc av carbon bisulpliidc gas 

 sufficient to kill all cLi'.iz' infestation, it wouM pi-obably i-esult in fatal 

 injury to the stock as well as the egff. 



Till' amount of in.j\ii'y to thr stock would likely be accorilinu to the 

 amount of moisture it coiitaiued. 



Other interesting experiences we have had in c(uinection with the 

 fumigation of nursery stock has been with such insects as Browntail Moth 

 larvae, Gipsy Moth egg clusters. Black, Woolly, (Jreen and other aphis, 

 lied Spider, Phylloxera, Narcissus Fly, etc. Also several sj)eeies of root 

 and stem borers. 



That with P.i-owntail ]\Ioth larvae, subjected to the usual formula 

 of Hydrocyanic gas, resulted as follows: 



Where the larvae renuiinetl undisturhi'd within their closely woven 

 nest of silk web, the gas apparently had very little or no effect. In nests 

 that were torn o])en. bef(u-e exposure to the gas, some of the larvae 

 appeared to he dead and othei-s moi'e or li'ss seriously ati'ected; they all 

 appeared to be deail within about forty-eight luuirs. 



GlI'SY JIoTII 



In spite of fumigation, a cluster of Gijisy Moth eggs from France 

 hatchiHl out to a firu', robust colony of young larvae. Tliey were not 

 turneil hiose, howe\'er. 



Aphis 

 Many of the adults of the different species of Aphis were killed by 

 the gas. but the eggs survived. The adults of the Woolly Aphis (Eriosoma 

 lanigera), apjienred to be the nu)st I'esistant, and we have often been in 

 doubt as to many of them idtinuitely surviving. 



Red SriDER 

 Tlie adults of the red spider evidently were all killed, but the young 

 s])iders commenced hatching from the batches of eggs when exposed to 

 the warm rays of the sun shortly after coming out of the fumigation 

 ciiambei-. 



PhYLLOXE[!A 



A<lults of the grape phylloxera (vastatrix), did not survive the 

 cyanide fumes, but there was always a possibility of eggs being over- 

 looked. For that reason any vines showing the phylloxera galls on the 

 roots \\-('yf discarded and burned, or retui'ned to the shipjjcr. 



Peach Root Borek 

 It would i'e(iuire a much stronger formula of hydrocyanic acid gas 

 than is usetl for ordinary fumigation of nursery stock to kill the peacdi 

 root borer (Sanninoidea exitiosa), althougli many of the larvae extracted 

 from their boi-ings in the roots of peach, ai)ricor. ()lum and cherry fi'ee.s, 

 appeal- scunetimes to be seriously affected by the gas. On some occasions 



