April, ’20] 
ISELY AND ACKERMAN: OZARK CODLING MOTH 
161 
six times showed as high or nearly as high an infestation as the check. 
To be sure, in these sprayed orchards the work had not been as thorough 
as was possible but in some it had been thorough enough to have con¬ 
trolled apple scab in a bad scab year. 
The infestation for the season of 1919 was less severe. Fruit from 
the check plats in the experimental orchards was only 47.55 per cent 
infested, and the?"extra worms” per apple were much less numerous. 
There were practically no dusted orchards in the region this season. 
In 1917 no experimental work was conducted in the Ozarks. How¬ 
ever, one of the writers was present during apple harvest and he found 
the codling moth not generally as injurious as it became the following 
season, but in some orchards the infestation ranged from 50 to 70 
per cent. 
The above data on abundance of codling moth during three seasons 
applies to the majority of orchards in this region. However, there are 
occasional orchards in which codling moth injury is comparatively 
light and in which the apparent immunity is not due to the effective 
application of remedial measures, but must be charged to natural 
conditions. These orchards are usually isolated and often quite dis¬ 
tant from the main fruit growing sections. In some instances these 
low infestations are directly attributable to the loss of a crop the pre¬ 
vious season because of frost injury or poor care. Conversely the most 
heavily infested orchards are regular bearers and in the heart of the 
fruit section. 
Seasonal History 
The seasonal summary which will be given herewith is based on 
insectary records which were checked up by band records and field 
observations. The rearing methods employed in the insectary were 
for the most part the same as those usually followed in the Bureau of 
Entomology and have been previously described. Battery jars were 
used for moth emergence, oviposition, and rearing of larval and pupal 
stages. Larvae were allowed to spin cocoons in the standard “pupa- 
sticks,” and jelly tumblers were used for incubation. Our methods 
differed from the usual as follows: Records of moth emergence and 
pupation of material in battery jars were checked up by records of 
material reared in wire cloth cylinders, which were kept both in the 
insectary and suspended around a tree trunk in the insectary yard. 
Oviposition from which incubation records were to be made was se¬ 
cured on pieces of dry twigs about two inches long. These seemed to 
us to have the advantage over leaves in that the latter when drying 
injured a percentage of the eggs. Paper was substituted for cheese 
cloth in making covers for the battery jars, when it was desired to 
prevent evaporation. 
