IVAR TRAGARDH: SKOGSENTOMOLOGISKA BIDRAG I—5. 207 
Summary. 
I. The Chalcidid Agenzaspis fuscicollis DALM. was found 
in the larvae of the two needle-mining microlepidoptera Ocre- 
rostoma piniartella ZELL. and Dyscedestis farinatella DvP. in 
the neighbourhood of Stockholm. The species which has a 
polyembryonic development, described by BUGNION, MARCHAL 
and SILVESTRI has previously been recorded from Y/ono- 
meuta cognatellus, Y. malinellus and Prays oleellus; conse- 
quently five species, all belonging to the Yponomeutinae, are 
known to be attacked by this parasite. 
It is evident, that the parasite deposits its eggs in the 
eggs of the miners, as this is the only opportunity of infec- 
tion the larvae offer, the larval instars being themselves pro- 
tected by the hard epidermis of the needle. When the larva 
is about to leave the needle it is quite filled by the parasites, 
which do not, however, interfere with its vital organs, the 
larva being able to change skin and start spinning the cocoon in 
a tube made of needles spun together. Only then, not be- 
fore, the larva succumbs to the parasites. As a rule from 
8 to 12 parasites develop in one larva (fig. 1). A large per- 
centage was infected in 1913, in some cases as many as 
75%; one could therefore antecipate, that in the following 
year the miners would be greatly reduced in number and, 
as a matter of fact, while in the spring 1914 they were fairly 
numerous, it was in the autumn very difficult to find any. 
As Ageniaspis fuscicollis has been recorded from not 
less than five different species of microlepidoptera and has 
a polyembryonic development, it seems probable that the 
species could with advantage be made use of against injurious 
forms of microlepidoptera. 
2. The foodhabits of Prezostethus cursitans FALL. were not 
previously known. The author found the nymphae under 
the bark of pine-trees, in the burrows of barkbeetles and 
ascertained that they fed on the larvae and pupae of these. 
The anterior femora are very powerful and their ventral edge 
