52 BULLETIN SS5, U. S. DEPARTMENT OF AGRICULTURE. 
danger of the black fly being brought in on parts of infested plants 
by passengers returning from a country where the pest occurs. 
SUMMARY. 
The black fly. Aleurocantnus icoglumi, was introduced into Jamaica 
from India on infested food plants within the last 10 to 15 years. 
From this focus in the Xew World it has spread to Cuba, Xew Provi- 
dence, the Canal Zone, the Republic of Panama, and Costa Rica, 
and is continuing its spread from these new centers. 
It was probably introduced into the Canal Zone between the years 
1912 and 1914, the introduction taking place on more than one lot 
of infested food plants. 
This report is based on an intensive study of this pest in the Canal 
Zone made from June, 1918, to August, 1919. 
The introduction and establis hm ent of this pest in widely separated 
areas has taken place through nursery stock or infested individual 
food plants, including cuttings for propagation. Within a region 
this method of spread is supplemented by the natural flight of the 
adults, by their carriage on vehicles and trains, and on the clothing of 
persons passing or working among infested trees. 
The important food plants of this insect in the Canal Zone are: 
Ardisia revoluta, various species of the genus Citrus, Coitea arabica, 
Eleais melanococm, Eugenia jambos and E. malaccensis, Lucuma 
mammosa and L. nervosa, Mdicocca oijuga, and Mangifera indica. 
This insect, under certain conditions, injures seriously plants in- 
fested by it. but no plants killed by it have been found in the Canal 
Zone and Republic of Panama. 
There are six stages in the life history of the black fly, namely, 
the egg : three larval instars, the pupa, and the adult. The life history 
is not clear-cut and there is a decided overlapping of stages. The 
length of time for the completion of one generation ranges from 45 
to 113 days. The duration of the various stages are: Egg, 11 to 20 
days: first larval instar, 7 to 16 days: second larval instar, 5 to 30 
days; third larval instar, 6 to 20 days; pupa, 16 to SO days; adult, 
probably 6 to 12 days. 
There is a great mortality in the various stages, only 22.5 per cent 
of the individuals of 790 eggs reaching maturity. 
The natural climatic factors that tend to hold the insect in check 
in the Canal Zone are: Drying out during the dry season and the 
heavy rains during the wet season. 
Five species of coccinellids and one species of Chrysopa have been 
found to be predacious on the various stages of Aleurocanthus woglumi 
but they are not as yet sufficiently abundant to be important factors 
in its control. Xo internal parasites were found. 
