August, ’23] 
HARTLEY: EUROPEAN PINE SAWFLY 
387 
the twigs, only a few larvae were found to a tree. A number of these 
over-winter cocoons were collected and a count disclosed 238 out of 321 
containing exit holes of parasites. At the same time several adult 
parasites were noticed ovipositing in newly spun cocoons and other 
adults of the same species were swept from the foliage. These were 
later determined by Mr. Gahan of the U. S. National Museum as 
Monodontomerus dentipes Boheman. Ninety-four freshly spun cocoons 
were taken June 16th which yielded 39 adult sawflies by July 2nd, and 
118 parasites from 15 cocoons. By July 14th, 59 more parasites had 
emerged from 12 cocoons. All of these parasites were Monodontomerus 
dentipes except 6 specimens of Eurytoma sp. and 2 Cryptus lophyri Nort., 
determined by Mr. Gahan. The 28 remaining cocoons were kept in 
storage at room temperature (70 degrees F.) until Jan. 5th 1923, 
when they were all opened. Four of the cocoons contained adults, 
mostly dead, of Monodontomerus dentipes , 16 others carried from 1 to 
15 living parasite larvae, and 8 bore dead and shriveled remains of 
sawflies. 
From the above figures, .this lot of 94 cocoons of the first spring brood 
of Diprion simile gave a parasitism of 53%, almost entirely Mono¬ 
dontomerus dentipes. 
Another lot of 123 cocoons collected July 17, 1922, gave one Diprion 
simile and a number of Monodontomerus dentipes by August 5th. No 
more sawflies or parasites emerged that season. The following January 
5, 1923, the remaining cocoons were opened and 86% were found to 
contain parasites in some stage, averaging 9 parasites to a cocoon. 
Twelve cocoons contained live pupae and three were full of dead adults 
of M. dentipes. The great majority, however, bore from one to 20 
larvae all very much alike. Two of the cocoons yielded the puparium 
of a fly, probably a Tachina. In one the fly had emerged inside the co¬ 
coon, but was apparently unable to reach the outside thru the tough 
walls of the cocoon. This condition has been previously noted by Dr. 
Britton. 5 
No evidence of secondary parasitism was noted in these dissections, 
unless, perhaps, in the presence of a few dead larvae, the cause of which 
was impossible to ascertain. 
Several cocoons contained the withered remains of the sawfly covered 
with a fungus mycelium, often with living larvae of the parasites, show¬ 
ing their ability to live with the fungus. 
In one or two cases, adult D. simile were found in their cocoons with 
Seventeenth Connecticut Report-. 
