56 
THE GRAPE ROOT-WORM. 
During the summer of 1909 parasitized eggs were in evidence in 
the field from July 20 to August 30, and were found locally quite 
abundant, though less so than Fidiohia Jlavipes. Professor Webster 
informed the junior writer that he had found a similar parasite in 
Ohio in 1896. Table XXIII shows the relative occurrence of para- 
Pig. 26. — Larva of an undetermined insect parasite of the eggs of the grape root-worm. (Original.) 
sitized eggs as observed at various stages in different localities during 
1909 at North East, Pa. 
Table XXIII. — Percentage of eggs of the grape root-worm parasitized by a dipterous 
insect, as observed in vineyards in the vicinity of North East, Pa., 1909. 
Date. 
Vineyard. 
Per cent. 
Julv 20 
Davidson 
1 
Julv 22 
Porter 
1 
July 24 
Mosher 
3 
Aug. 4 
7 
Aug. 12 
do 
22 
Aug. 19 
do 
12 
Aug. 20 
do 
14 
It will be noted that there is an increase in the occurrence of the 
parasite toward the end of the season, as was observed with Fidiobia. 
Koot-worm eggs parasitized by this insect are in their early stages 
opaque-white in color. Later the eggshell becomes semitransparent 
and iridescent. The larva of the parasite when full-grown is almost 
twice the length of the host and lies folded within the egg. The 
whitish larvae are very active on emerging from the hosts. They 
were found to penetrate several inches in the soil in glass jars. Though 
the larva is quite common, all attempts to rear the insect to obtain 
the adult or fly have so far proved fruitless. 
DOUBLE PARASITISM. 
August 30, 1909, a cluster of 115 root-worm eggs was collected, 
which were infested by the dipterous parasite. The egg along the 
border of the cluster, unlike the rest, a few days later assumed a pink 
color, but at the same time showed the iridescence characteristic of 
this parasite. Dipterous larvae emerged September 3 from the eggs 
of the central portion of the cluster. From the eggs along the border 
of the cluster a hymenopterous fly (Lathromeris Jidise Ashm.) (fig. 27) 
