December, '23] 
stear: red bug control 
549 
Grimes Golden, Stayman Winesap and Jonathan. In 1921 the first 
nymphs were observed on April 7th, as many as six nymphs being found 
on a single blossom bud cluster. On this date all four varieties were in 
condition for spraying in the pink. By April 9th, however, all were 
partly in bloom except the York Imperial which did not bloom until 
April 14th. In 1922 the first nymphs were observed on April 23rd. 
At this time all varieties were in the pink stage, but by April 26th all 
were in bloom except the York Imperial which did not bloom until 
May 1st. 
From this it appeared that except in the case of the late blossoming 
York Imperial, hatching occurred so late in the pink stage that the 
pink spray could not be delayed long enough to catch the nymphs. 
Even if it were possible to delay the pink spray until a couple of days 
before the blossoming period, not more than 50 to 75% of the nymphs 
would be exposed to the spray. In 1923 hatching occurred over a 
period of 6 days. Twenty-five percent of the nymphs hatched in the 
last four days of this period, during which time the trees were in bloom. 
Frost 3 has shown that the hatching period of L. mendax occurs too 
late for the pink spray to catch many of the nymphs, and recommended 
that in red bug control nicotine be applied at petal fall and two weeks 
later rather than in the pink spray. 
In order to compare the effectiveness of later sprays with the pink 
spray, and also to determine whether sufficient additional control is 
secured to justify two applications of nicotine, experimental spraying 
was carried on in an infested York Imperial orchard in 1922. 
The orchard was divided into four plots which were treated as follows: 
Plot 1 sprayed in the pink. Plot II sprayed in the pink and at petal fall. 
Plot III sprayed at petal fall. Plot IV sprayed at petal fall and 2 
weeks later. Check trees were left in Plot I. The trees were twelve 
years old and 3-3jY gallons of spray were used per tree. Nicotine 
sulfate was used at the rate of pint to 100 gallons of dilute lime- 
sulfur. The pink spray was applied on April 26th, three days after 
nymphs were first observed. Petal fall spray was applied on May 8th, 
and the third spray on May 26th. 
3 Jour. of Ec. Ent., Feb., 1922 
