THE “FALL WEB-WORM. 51 
In the earth of the jar were found 28 pup of Tachina flies, leaving 
76 caterpillars and 3 pupe killed by fungus, or 63 per cent. 
In both experiments it has been assumed that each Tachina fly had 
killed one caterpillar. 
On November 15, 1886, the jars were again investigated, and it was 
found that a number of the pup had been killed by the fungus since 
October 18, 1886, and that in fact all the remaining ones did not look 
healthy. The percentage of death by the fungus in the two experi- 
ments was thus increased to 63 per cent. in Experiment I and to 67 
per cent. in Experiment II. 
TRUE PARASITES OF THE WEB-WORM. 
Up to the present time no parasites of this insect have ever been re- 
corded. On August 18, 1883, we bred a number of egg-parasites from 
a batch of eggs found upon a willow leaf at Washington, but unfortu- 
nately no description was made of them at the time, and, as they be- 
longed to the soft-bodied genus Trichogramma, the specimens have 
now become so much shriveled and altered that they are unfit for de- 
scriptive purposes. We noticed after our return from Europe in Sep- 
tember of this year that, at a number of points in New England, the 
worms were quite commonly attacked by parasites, and careful inves- 
tigation at Washington by Mr. Lugger showed the presence of no less 
than five distinct species of primary parasites in addition to the Trich- 
ogramma just mentioned. These will be considered in some detail. 
The first was a new egg-parasite which we have named Telenomus bi- 
fidus ; the others were all parasitic on the larvie, and consisted of a 
Braconid (Meteorus hyphantrie n. sp.); a Microgaster (Apanteles hyphan- 
trie, n. sp.); an Ophionid (Limneria pallipes Prov.), and a Tachinid, 
which, though probably new, we shall not attempt to describe. These 
last four have been mentioned in about the order of their relative abun- 
dance and consequent importance. An astonishing number of Web- 
worms were killed by the four parasites, and so many died from this 
cause and from the fungus disease previously mentioned as to fully 
warrant the prediction of almost complete immunity for the summer of 
1887. 
In addition to these parasites found last fall, the note-books of the 
Division show. a prior breeding of another primary parasite, which will 
not be treated in detail here on account of insufficient material. It is 
an external feeder on the larva and belongs to the genus Huplectrus. 
It is closely related to E. platyhypenc, described by Mr. Howard in Bul- 
letin 5 of this Division. : 
Telenomus bifidus Riley.—A single egg of the moth of H. cunea is a 
very small affair, yet it is large enough to be a world for a little para- 
site, which undergoes all its transformations within it, and finds there 
all the food and lodgement required for the short period of its life. 
