THE KICE MOTH. 13 
Hydrocyanic-acid gas, it must be stated, is the most poisonous 
substance in common use, but it is still employed very extensively 
in fumigating mills and dwellings, and if the directions in the 
bulletins cited are carefully carried out there is really no danger to 
human beings. 
CARBON DISULPHID. 
Before the general adoption of hydrocyanic-acid gas as a means 
of fumigating buildings, carbon disulphid was considered a standard, 
and it is still of value, particularly on a small scale, as a substitute 
for hydrocyanic-acid gas. It is extremely inflammable, however, 
which has led to its abandonment in many localities. Directions for 
its use are given in Farmers' Bulletin 799 1 " Carbon Disulphid as an 
Insecticide." 
SUMMARY. 
1. The rice moth (Corcyra cephalonica Staint.) has been known 
to occur in the United States only since 1911, and was not identified 
until 1916. 
2. Its origin is unknown, but it has been introduced at many points 
in other continents and is as yet not strictly cosmopolitan. It has 
been found commonly in England, where it was introduced in rice, 
chiefly from India and Burma, and also in dried fruits. 
3. Its habit of feeding on cacao beans is probably an acquired one. 
Evidently it is inclined to be omnivorous, since it breeds in rice, 
dried fruits, the various products of cacao, such as cocoa, cacao 
shells, and sweetened and unsweetened chocolate, ship biscuits, and 
sesame seeds. It displays, however, no partiality for any of these 
food substances. 
4. Its complete life history has not been traced, but, like other 
indoor species, it reproduces nearly the year around under average 
conditions. In the United States infestations appear to die down 
from time to time, but are stimulated through new shipments of 
cacao beans from South America and Central America. 
5. It produces copious and dense external webbing to which food 
materials, such as rice, cocoa, and other matter, strongly adhere. 
In this respect its work and injury resemble those of the fig moth 
(Ephestia cautella Walk.) and related species, and the Indian-meal 
moth (Plodia int&rpv/nctella Hbn.). 
(6) While it has been recognized only from western Pennsylvania 
and Porto Rico, it occurs without doubt at other points, and dealers 
in rice, chocolate, and similar imported dry edibles should keep a 
1 The Farmers' Bulletins mentioned may be obtained free on application to the Division 
of Publications, United States Department of Agriculture. 
