io8 
Psyche 
[March-June 
in the carbohydrate components, he supplemented the honey diet with 
several synthetic foods known to contain high proportions of proteins 
(or their products of hydrolysis) and B-complex vitamins. All were 
found to raise egg production well above the level obtained on 
honey alone. 
This early work led to further efforts toward developing highly 
nutritious, semi-defined, laboratory diets which would permit the 
efficient mass rearing of large numbers of adults (Finney, 1950; 
Burke and Martin, 1956; Hagen and Tassen, 1966, 1970; Ridge- 
way et al. y 1970). 
None of these investigations attempted to determine the natural 
feeding habits of the adults of C. carnea. We have therefore cen- 
tered our attention on a qualitative attempt to discover the food 
utilized by adults under natural conditions. This has involved an 
analysis of the gut contents of field-collected individuals and observa- 
tions on the feeding behavior of adults in the field. In addition, as 
large numbers of wild adults were found feeding on corn pollen 
during the summer, we have investigated the efficiency of this ma- 
terial as food. 
Materials and Methods 
Since it has been sugested that honeydew is an important natural 
food of C. carnea (Hagen, 1950; Neumark, 1952), we began our 
study with a microscope examination of leaf-surface honeydew in 
order to obtain a standard of comparison for our study of gut con- 
tents. This was carried out using two methods. In the first, leaves 
covered with honeydew were washed in a beaker containing distilled 
water, and the washings were then poured into a centrifuge tube and 
spun down. The pellet was placed in a drop of warm glycerine 
jelly on a microscope slide, a cover slip was added, and the prepara- 
tion was gently squashed to flatten it. The second method utilized 
unfed, lab-reared adults which were permitted to feed on leaves 
covered with fresh honeydew, and an examination was then made 
of the slide-mounted gut contents. In these preparations the crop, 
midgut, and hindgut were removed in an isotonic 0.75% NaCl 
solution (MacLeod, unpublished) and these were mounted directly 
into glycerine jelly as described above. Studies of the gut contents 
were also made from similar whole mounts of the crop, midgut, 
and hindgut of 133 field-collected individuals which had been col- 
lected at various times throughout the year. These samples were 
taken, depending on the season, from woodlands or agricultural fields 
