28 ANNUALS UtTMENT OF AGRICULTURE, 1940 
Reduction of the Comstock mealybug to b pest of noncommercial 
importance led to the discontinuance oi the Charlottesville laboratory 
at the end oi the L848 field season. 
Steps Taken to Combal Oriental Fruit I 1\ Menace 
(i g to the seriousness of the oriental fruit fly problem in Hawaii 
and the potential importance of the pest should it reach the mainland 
of ilic United Male-, increased funds were made available for a study 
of this fly in cooperation with local attention was 
given to inspection and treatment of plane- leaving Hawaii for the 
mainland and inspect ion of ships and pas e gat mainland 
ports. The use of vapor heat was authorized for the treatment of 
papayas and both vapor heat and methyl bromide fumigation for 
orchids prior to shipment. 
In addition to regular funds for biological studies and experiments 
to find i ontrol measures, an i \ e isive cooperative project in 
biological control was undertaken with funds authorized under the 
iivh and Marketing Act. Natural enemies of this fly are now 
being sought in South A Erica, Malaya, and India. Shipments of three 
es of parasites and one predator have been received from Malaya 
and of one species from the Philippine Islands, and about 70,000 para- 
have been reared and released in Hawaii. Each of the parasites 
been recovered at one or more points of release. 
Further expansion of the program, in cooperation with several 
lies in Hawaii and the State of California, is contemplated for 
the coming year. Five line- of research will he undertaken — (1) 
biology and habits of this fruit fly, (2) treatment of infested agricul- 
tural product- so that they may he transported safely into uninfested 
areas, (3) search for insecticides that will kill the insect. I h large- 
scale control and eradication experiments, and I 5 i biological < •ontrol. 
The oriental fruit fly situation in Hawaii is a typical example of 
what an insect pest can do when it gains access t<> a favorable habitat 
where it- natural enemies are not present to check it. This fly is be- 
lieved to have 1m -en brought to the Islands in fruit from Saipan in L94 i- 
or 1945, but was first recognized there in L946 in a mango grown in 
Honolulu. It ha- heel i foil nd in more than 100 \ ariet ies of fruits and 
ibles, in the blooms of "tie variety of Vanda orchids, and even 
tton bolls. It- favorite wild host is guava, which is abundant in 
Hawaii. Biological studies indicate that it has no hibernation stage, 
that it i- long lived- adults may live for ! months — and that it is 
adaptable to a wide range of climate and altitude and could thus 
probably survive many climate- on the mainland. 
Sprayi ami Parasite* Used igainsl the Citrus Blackfl) in Mexico 
R earch directed against the citrus blackfly, which Is a widespread 
and ~ o i ; < » u - p. -i of citrus in Mexico, was con t inued in cooperat ion with 
the Mexican Government. The purpose was to find more effective 
means of controlling tin- blackfly in Mi d thereby to protect 
fruit I ltd St ates. 
