; ■ j ..-8.1-.. 
The -Connecticut AgricuLtural^Experiment Station (62) in 1938 reported 
that derris dusts 'were -applied.* j, a -July to control apple- maggots. Regular 
sureysVere discontinued ef ter , Jupe ^5 end three amplications of a dust 
containing 0.5 percent of rotenone,- Fere made in July and August. At the 
station* farm the results were .better than for several' years past... At 
West ^oods,' where, a similar schedule was followed,' the reduction in 
injury amounted, to approximately. 3.8 percent. 
German (94) in 1.938 reported .-that e dust containing 0.5 percent of 
rotenone applied ^ith a po^er .duster , seemed to have considerable toxicity 
for the apple maggot fly. In -laboratory tests materials that proved to 
he effective when used as dusts were ineffective 'after being wet down and 
applied as a spray, even though considerable amounts were used in the 
• spray. -Apples heavily dusted were left for s few days in a greenhouse 
exposed to moisture and light. In these tests freshly applied dusts 
showed much greater effectiveness than similar dusts that had been exposed 
in a greenhouse for 5 days. 
G-arman and Townsend (97) in B38 reported further studies on apple 
maggot control. In both laboratory and field tests a 0.5-percent-rotenone 
' dust, with clay as a carrier, was shown to be more effective than lead 
arsenate in killing the flies. Exposure to li^ht under greenhouse con- 
ditions destroyed -the insecticidal action of rotenone dust corrroletely in 
; 5 days. Using the dust as a spray also destroyed its efficiency. 
The Ne'-' Jersey Agricultural Experiment Station (212) in'1938 stated 
that cage tests of insecticidal dusts against the adult fly were con- 
tinued in that year with a total of 621 individuals in 34 lots. It was 
found that, in equal amounts, powdered brrbasco and derris ^ere eoually 
toxic, each* resulting 'in a. practically complete.'kill ^here 2.5 rag, of 
4-percent materiel was used in cadres of l/3-cubic-f oot capacity. The 
same quantity of 6.7-percent timbo produced only a '50-percent kill. he 
substations recommendation of 2 applications of 10 pounds of powdered 
derris per acre spread by aircraft' on June 27-30 and Julv 7-10 was continued. 
The'Nevr York Agricultural Experiment Station ( 216 ) in 1938 reported 
on insecticides, including phenothiazine, powdered cube root, and hydrated 
lime, "hi ch were tested under orchard conditions against the apple maggot 
in']936. Six small orchards '"ere treated, all the trees in each block 
receiving a 'single te<st. material.. Little or no control ^as obtained where 
hydrated lime alone was- used,- but the results from cube root and pheno- 
thiazine. were sufficiently promising to warrant additional testing. 
The New York County Age^*?9..Trairfin| School ( 213 ) held at Ithaca in 
1938 heard a report that further tests with rotenone in the form of 
powdered derris and cube root resulted: in' very poor control of the apple 
maggot. Apparently this material is "out" as an insecticide against this 
pest. 
