330 ENTOMOLOGICAL NEWS. [July, ’12 
collect some of these globules and give them to the parasites as a 
substitute for their accustomed host eggs. The idea seemed so 
absurd, however, that only after a complete failure to obtain moth 
eggs was it put into execution. 
Twenty of the juice globules were collected, some of them a little 
smaller, some a little larger than the eggs of the bollworm, Heliothis 
obsoleta, a favorite host of Trichogramma. These were placed in a 
small glass vial, and a female Trichogramma which had been in a tube 
with males of the same species was introduced. She quickly went to 
a globule and soon oviposited three times in it. There was a short 
interval between each two ovipositions. She then oviposited in each 
of four other globules. Then after running about for a few seconds 
she rested on the side of the vial. The vial being shaken slightly, she 
ran about again, got on a globule, but did not oviposit. In a few sec- 
onds she became motionless. The tube was slightly moved, and the 
parasite ran about but did not oviposit. She soon came to a resting 
position on the side of the vial, and was not observed to oviposit 
again. 
The globules were observed carefully for several days, and, as may 
be expected, they all dried up without the emergence of any parasites. 
The female of Trichogramma is usually represented as carefully 
inspecting the host egg to learn if it is suitable for oviposition, and I 
have often observed females walking over the eggs and touching them 
many times with the antennae, but it seems from these observations 
that the female is unable to ascertain whether the egg is suitable or 
not. 
Unless it be admitted that the mature female is impelled to oviposit 
in anything like a moth egg which is at hand, it seems clear that she 
is unable to learn not only whether or not a host egg is already para- 
sitized, unless it has turned black, but even whether it is of a suitable 
species or whether it is an egg at all. The parasite under considera- 
tion is known to have some forty-three hosts, and is supposed to 
oviposit in any soft-shelled egg, within certain limits as to species. 
The globules of okra juice were surrounded by a film formed by the 
exposure of the juice to the air, and were fairly good as an imita- 
tion of the egg of a Noctuid. It seems probable that Trichogramma 
oviposits in many unsuitable eggs, at least under conditions of 
scarcity of its usual hosts. 
The reason for the careful examination of the egg by the female 
is a subject for further speculation. Possibly the examination serves 
merely to locate a suitable place for the insertion of the ovipositor— 
T. E. Hottoway, U. S. Bureau of Entomology, Audubon Park, New 
Orleans, La. 
