NUIM.KY STOCK FOB SHIPMENT. 55 
larvae and pupa 1 of thr while fly. To destroy the eggs, however, he 
found that a larger dose was necessary. The author fully concurs 
with Professor Gossard in his recommendation to defoliate completely 
all white fly infested nursery stock before shipping, and, as an extra 
precaution, to fumigate. The almost invariable experience of Florida 
nurserymen, however, shows that citrus trees should not he fumigated 
with roots bare. The Fumigation is far less necessary than when the 
insects concerned are true scale insects and are at t ached to the stems. 
White flic's have never been known to reach maturity except on the 
leaves, although eggs and crawling larvae may occasionally he found 
on young growing shoots. It is safe to presume (hat there are no 
unhatched eggs of the white fly on anything other than leaves and 
young succulent growth of stems. When these are completely re- 
moved there need he no fear that the pest will he carried by means 
of the trees. The entire leaves, including the winged had' petioles, 
must he removed, and when large shipments are concerned careful 
attention must he given to this. A greater danger than the trees 
themselves is found in the packing. This, as Professor Gossard 
points out, might be a possible source of danger if infested citrus 
leaves were allowed to get into the moss or other material used in 
packing. The danger is, of course, slight, but should nevertheless 
be borne in mind by shippers and buyers of nursery stock. 
PRECAUTIONS. 
As is customary in publications on entomology in which the use of 
potassium cyanid is recommended in combating insect pests, atten- 
tion is directed to the extremely poisonous nature of this substance. 
There are on record no fatalities due to the use of potassium cyanid 
a- an insect icicle against orchard pests, but this is because the danger 
from careless use was well known and simple precautions were 
observed. In weighing the doses it is recommended that the hands 
he protected by leather gloves, and after starting the generation of 
the gas the operator should avoid breathing until he is outside in the 
open air. A slight choking sensation experienced when standing 
close to the tents during the fumigation acts as a danger signal, and 
one should not persist in remaining where 4 the gas is dense enough to 
produce this result. The acid should always be handled with great 
care. In addition to precautions necessary for the safety of the 
operators, care should betaken to avoid the scattering of small parti- 
cles of the cyanid where fowls or other animals might become poisoned. 
As this substance is readily soluble in water and is deliquescent, or 
capable of liquefying through the absorption of moisture from the 
aii-. -mall particles accidentally dropped soon disappear. 
