
- Fo 
in the stocks examined, with an average percentage of infestation of 1/4 
of 1 per cent. One lot of Emperor treated in 1930 in hot water with 
Ceresan added showed about 65 per cent with the centers injured and these 
were generally infested with Eumerus larvae. This is the only substan— 
tial source for Eumerus bulbs for fumigation and treatment experiments 
located as yet." Concerning experiments with poison—bait spray at this 
laboratory, Mr. Doucette says: "A small planting of bulbs sprayed with 
the formula used for cherry fruit fly in this section (arsenate of lead, 
brown sugar, molasses, and water) as mentioned in the May report, showed 
* * * Spring Glory--2,818 bulbs, 2 infested with Merodon; and Emperor-—— 
2,979 bulbs, 2 infested with Mercdon." Tests of vapor—-heat sterilization 
in July involved the treatment of 25 tons of narcissus in the laboratory 
equipment and 42 tons in a commercial outfit under supervision of the 
staff of the laboratory. 
In tests of pyrethrum extracts combined with dilute soap solu-— 
tions for use against greenhouse insects, H. H. Richardson, Washington, 
D. C., reports that "the concentration of soap which gave good wetting and 
Spreading qualities and yet did not produce any decided kill of aphids 
was determined. Against M. sanborni it appeared that 0.1 to 0.2 per cent 
soap (1,1-000 to 1-5,000) will give the desired effect. Dilution of a 
chemically pure soap solution with either tap water or distilled water did 
not appear to make any difference in the insecticidal action toward the 
black chrysanthemum aphid. The insecticidal action of the pyrethrins 
against the mealybug (Pseudococcus citri Risso) on coleus * * * indicates 
that the pyrethrins in any of the combinations tested were not effective 
against the mealybug. * * * Only very immature stages that had just 
previously hatched from the eggs were killed by these sprays." Of the 
many other insecticides tried against this insect, only the petroleum oil 
sprays gave any effective control. 
BE. A; McGregdr, Lindsay, Calif., reports: "The almost unprece— 
dented continuance of extreme temporatures acted to release at a high 
rate the toxic gases from the sulphur remaining on the citrus foliage, 
and this sulphur sublimation discouraged the natural restoration of the 
(citrus) thrips population, and contributed also to the reduction of the 
scale population." As for the seasonal development, eight generations of 
thrips had developed up to the end of July. Preliminary inspections of 
the sulphur-dusted plats as well as commercially treated ones reveal 
satisfactory protection from thrips attack with "almost no sulphur burn 
of fruit or foliage." In contrast, "untreated orchards as a rule are 
exhibiting more than the normal amount of thrips-scarred fruits." 
P. A. Berry, Santiago, Cuba, reports that as a result of para- 
sitism four groves -in Cuba are now commercially free from the citrus 
black fly. Parasitism by Eretmocerus serius Silv. ranged from bOLTON TS 
per ents. ae er . ae —_ 
A report to the Governor of the Panama Canal on the condition of 
the timbers in the shipworm (Teredo) test plats at Balboa, C. Z., has been 
made by James Zetek. The report states that the only timber practically 
free from all growth was alazane (Calycophyllum candidissimum Vahl.), 
whereas timbers close to it were heavily coated. Samples of 20 different 
types were examined. 
