August, ’20] 
STEARNS: LASPEYRESIA CONTROL 
365 
by their combination with some material possessing these specific 
characteristics. Sea moss solution (prepared by boiling 4 pounds of 
“Irish” rock moss for one hour, straining and diluting to 50 gallons of 
water) and a casein-lime mixture (proportions 1 part casein to 3 parts 
hydrated lime; rate 1 pound to 50 gallons of water) fulfilled best these 
requirements. Microscopic examinations have shown that, in in¬ 
stances where the insecticide had failed to kill an egg, and the young 
larva had succeeded in projecting the head partly through the forty- 
five degree angled aperture which is made, the thin flakey film of sea 
moss served often as a barrier to halt the normal hatching process at 
that point. The inexpensiveness of this material repays largely the 
time and labor involved in its preparation. Applications of calcium- 
caseinate resulted in a uniform conspicuous coating of the foliage,, 
which, in field tests, persisted for a number of weeks despite heavy 
rains. 
Laboratory Tests 
The method of procedure included the confining of moths in ten-inch 
breeding cages (double height) in the box bases of which one-year-old 
peach stock had been planted. Life-history studies in 1918 had shown 
that a high percentage of infertile eggs were deposited, due undoubtedly 
to laboratory conditions of confinement. The eggs deposited upon the 
foliage of these trees were, therefore, given a careful examination with a 
hand lens. Thus only those eggs which presented a well-rounded nor¬ 
mal appearance and were apparently viable entered into the experi¬ 
ments. In applications, which were made with an atomizer, care was 
taken to hold the atomizer in such a position that only the spray 
mist floated over the foliage. Twenty-one experiments, comprising 
twenty-four tests with eight insecticides, in which a total of 2,877 
eggs were studied individually under a binocular microscope, were 
conducted at the Leesburg Field Laboratory. Following applications, 
each egg was examined daily to observe the effect of the sprays and to 
secure accurate hatching records. 
The results with nicotine in these experiments seem a further contri¬ 
bution to our knowledge of the usefulness of this material, and as such 
deserve special notice. In view of observations made in experiments 
of the preceding year, the efficiency of the nicotine-arsenical combina¬ 
tions in Table I has been computed by comparing the total number 
of eggs not hatching and larvae dead 36 hours after hatching, with the 
total number of eggs employed. The percentage of kill for all these 
combinations in which nicotine sulphate (40 per cent) occurs as a toxic 
constituent may be computed as 79.69. The results with nicotine 
sulphate (40 per cent) and sea moss stand alone, 95.40 per cent of the 
