21 
Summary. 
1. Carcelia gnava Meig. x ). 
This species was reared from Stilpnotia salicis and Malacosoma 
neustria. On a willow hedge a great number of various cater- 
pillars were seen in July and August 1905 and at tke same time 
some moths of Stilpnotia were observed tbere occupied with the 
oviposition. The number of this species was not extraordinarilv 
great, but in the following years the number increased so much 
that in 1907 the caterpillars had eaten all the leaves of the willows. 
In June that year I found a great number of moths and at the 
same time many pupæ, which were conglomerated in lose spins 
among the leafless branches and not, as in normal cases, singly 
hided in a contorted leaf. On the willows also many full grown 
and younger caterpillars were climbing in search for foot. The 
Carcelia gnava was present, but in so small numbers that I only 
succeded in rearing one single specimen from a great number of 
the caterpillars. 
In 1908 the number of caterpillars was somewkat decreasing 
and in the next year 1909 most of the willows were green, still 
the number of caterpillars was considerable. By means of proofs 
from diverse points of the hedge it was found that a little more 
than 50 °/o of the caterpillars were infested with maggots of 
Carcelia gnava. In 1910 only a few caterpillars were seen and 
of these allmost all were killed by the parasites before they were 
half grown. 
The eggs of the fly are pedicelled, the chorion is thin and 
transparent; the surface shows a network of ridges enclosing polygonal 
areas. The posterior end of the shell is produced into a thread- 
like prolongation, the end of which is slightly dilatated and 
*) The dy which I named Carcelia gnava in a previous paper (Iagt¬ 
tagelser over entoparasitiske Muscidelarver hos Arthropoder Kbhvn. 
1909) has been examined by Dr. J. Villeneuve, who kindly has 
communicated to me, that it belongs not to this species but to 
Carcelia comata Rond. 
