BULLETIN 1028, U. S. DEPARTMENT OF AGRICULTURE 
tirely stramineous, and the three basal abdominal tergites are more 
coarsely rugose, the roughening on the third tergite extending well 
toward the posterior margin medially; the narrow lateral mem- 
branous margins on the apical fourth of the first abdominal tergite 
are testaceous in A. solitarius, while they are piceous black in A. 
melanoscelus. 
METHODS USED IN BIOLOGICAL WORK. 
As this species hibernates as a maggot within its cocoon, it is a 
simple matter to gather material during the fall and winter for study 
in the spring. The cocoons were kept in the laboratory yard during 
the winter, in cylindrical cages 3 by 8 inches, made of very fine copper 
netting. Occasionally during the winter a few cocoons were dis- 
sected to ascertain the condition of the maggots and to note any 
changes which might have taken place. As spring approached, the 
cocoons were iso- 
lated, being placed 
in small gelatin 
capsules, or small 
glass vials 1J inches 
by J inch. It is nec- 
essary to isolate each 
of the cocoons at 
this time of the year 
for two reasons : 
First, so that .one 
may know the exact 
age of the adults 
with which he is 
working and keep the males and females separate; second, to pre- 
vent any secondary parasites which may issue from the cocoons 
during the spring from ruining the rest of the Apanteles material. 
As soon as the Apanteles issued they were removed from their con- 
tainers and placed in glass tubes or glass-covered trays (fig. 1) , where 
they were fed a mixture of equal parts of water and honey. A con- 
venient method of feeding is to dampen a small piece of clean sponge 
with the food and place it in the tube or tray containing the Apan- 
teles. The sponge should be washed out every day or so and damp- 
ened again with a fresh mixture of honey and water. 
Parasite-free gipsy-moth larvae were obtained by rearing them 
from eggs, and a supply was kept in trays protected from parasites 
ready for use at all times. 
Two sizes of glass tubes were found convenient, a small one 4 
inches by 1 inch for isolated individuals, and a larger size, 8 by 2 
Fig. 1. — Tray with glass top used in life-history experiments 
with Apanteles melanoscelus. (After Culver.) 
