9I8 PARASITES OF GIPSY AND BROWN-TAIL MOTHS. 
even presuming that 7. /arvarum should not be established, but the 
chances are not particularly in favor of such an outcome. It has 
not been so long nor so satisfactorily colonized, and there is yet a 
chance that it will be recovered as a result of the colonies which have 
been planted, or which are likely to be planted in the future. No 
especial attempt will be made to test its ability to exist asa race apart 
from T. mella, but it is expected that its puparia will be imported in 
some numbers in 1911 or in 1912, in connection with work involving 
the importation of other Japanese parasites. 
TRICHOLYGA GRANDIS ZETT. 
Although generically distinct from Tachina, according to the at 
present accepted and as is increasingly evident artificial classification 
of the Tachinide, Tricholyga grandis is so similar to Tachina mella 
and T. larvarum as sometimes to be separated with difficulty from 
those species. In Europe Tachina and Tricholyga attack the gipsy 
moth with nearly equal freedom, but relatively a very few Tricholyga 
have been reared from the brown-tail moth. The fact that Tachina 
and Tricholyga do not usually occur in the same locality the same 
year has already been the subject of comment. If may be that a 
careful review of the rearing records of the two will show that 
Tricholyga is increasingly important as a parasite in the more south- 
erly localities, but such review has not been made with this point in 
view. | . 
It was not until 1909 that it was definitely separated from Tachina 
in the records of the rearing and liberation of the tachinid parasites, 
and up to 1908 the two species were so inextricably mixed as to make 
it very difficult to state with any approach to accuracy the relative 
proportions of the two among the number colonized. There was 
only a single specimen of Tricholyga among the several Tachina which 
were preserved for museum specimens from among those imported 
in 1906 and 1907, and on this account it is probable that Tachina was 
in the considerable majority. 
In habits Tricholyga differs from Tachina in only a single con- 
spicuous respect. It deposits the same sort of eggs, similarly placed; 
its larvee appear to have the same feeding habits, and about the same 
length of life cycle; but unlike Tachina it seems habitually rather 
than occasionally to pupate within the caterpillar skin or pupal shell 
of its victim. On this account some of its puparia have been diffi- 
cult to find in the boxes of imported caterpillars, and it has been 
found advisable when they are present at all, to keep the dead cater- 
pillars inclosed until such flies as are present have emerged. 
Like Tachina, it probably hibernates in the puparium, but neither 
of the two has ever attempted to hibernate when reared from im- 
ported European gipsy-moth caterpillars. The introduction and 
