38 ANNUAL REPORTS OF DEPARTMENT 01 AGRI( QLTURE, 105 1 
ous contaminant of the fly's basic food supply. This 
is indicated by the fad thai an effective bait spray can be made with 
parathion in combination with protein hydrolysate and sugar. This 
bail spray is also effective against tin* Mediterranean fruit fly and 
the melon fly. 
v pious effects on beneficial were observed following the 
use of at least Ave of the compounds tested. Even though further re- 
search should result in refinements of methods and the discovery of 
effective materials or formulations better suited for widespread appli- 
cations in populated areas, it is believed that data necessary for the 
intelligei i insecticides in an eradication program arc now 
available. 
Eradication nearly accomplished on Lanai 
A large-scale control program was undertaken on the island of 
Lanai following a year of basic preparat ion in test areas. The opera- 
tion comprised a series of large-scale experiments that together covered 
the known fly-breeding and concentration areas on the island. The 
control achieved can be evaluated by the fact that fly collections from 
banana t rap- fruit at Lanai ( Jity were completely negat ive for 1 months. 
Complete eradication was not expected because of reinfestation by 
flight from other islands. The control operation was considered a 
complete success and one that could be duplicated in case of an incipi- 
ent infestation on the United States mainland. 
Life-history studies develop basic information 
Controlled laboratory experiments by a physiologist have con- 
firmed field observations that temperatures below 60* V. generally in- 
hibit the mating of sexually matm-c flies, but that a decreasing Light 
intensity, not necessarily dusk, is a primary factor in the inhibition. 
The use of carbon dioxide as an anesthet ic greatly assisted in the criti- 
cal examination of flies in the laboratory. 
The biology and ecology of the fly have been studied on the moun- 
tain- on Hawaii and Mani tip to altitude- of 9,200 feet, Basic in- 
formation has been obtained on longevity and the preoviposition 
period, as well as egg, larval, and pupaTsurvival in both favorable and 
marginal areas. The studies provide a basis for estimating the sur- 
vival possibilities of the fly on the mainland. Several new and unique 
instruments to simulate mainland temperature and humidity were 
devised to facilitate tin 4 st udies. 
Close to 5 tons of fruit, including 300,000 individual fruits, was 
collected in the field. The collections yielded information on fly 
parasite complexes, host preference, and nost sequences under which 
fly populations may be built up. Ahout three-quarters of a ton of 
California grown host material was received for exposure to fly attack 
i md determination of its susceptibility to infestation. 
[ncidental observations show that Mediterranean fruit Hies and 
melon flies are also a hazard to agriculture in the Stat 
Citrus Blackfly Investigated 
Survey for citrus blackfly continued 
S rvej in northern Mexico were continued to spot incipient infes- 
tations of the citrus blackfly so that they might be suppressed before 
