KATUEAL ENEMIES. 



53 



Table XXI. — Parasitism of grape root-iuorm eggs by Fidiobia flavipes at North East, 

 Pa., 1909, the eggs ranging in age from 1 to 9 days. 



Obser- 

 vation. 



Grape root-worm 

 eggs. 



Hatched. 



Parasit- 

 ized. 



Oviposi- 

 tion. 



Normally 

 hatching. 



1 

 a2 

 3 

 4 

 5 

 6 



8 

 9 



July 30 

 July 31 

 Aug. 1 

 Aug. 3 

 Aug. 4 

 Aug. 5 

 Aug. 6 

 Aug. 7 

 Aug. 8 



Aug. 11 

 Aug. 12 

 Aug. 13 

 Aug. 14 

 Aug. 17 



...do 



Aug. 21 

 Aug. 24 

 Aug. 26 



X 

 X 





X 

 X 

 X 

 X 

 X 

 X 

 X 















a Parasites placed with the host August 9. New parasites emerged September 10 to 12. Thirty-two to 

 thirty-four days to complete the life cycle. Experiment No. 2 consisted of 15 root-worm eggs, of which 13 

 became parasitized and 2 eggs developed root- worms normally. Eggs within two to three days of hatching 

 escaped parasitism. 



Table XXII. — Parasitism of eggs of the grape root-worm by Fidiobia flavipes , at North 

 East, Pa., 1909, eggs ^varying in age from fresh to 10 days old. 



Num- 

 ber of 

 obser- 

 vation. 



Root-worm eggs. 



Num- 

 ber of 

 eggs. 



Emerg- 

 ing root- 

 worm 

 larvae. 



Hatch- 

 ing of 

 para- 

 sites. 



Oviposi- 

 tion. 



Normally 

 hatching. 



1 



2 

 3 



4 

 5 

 6 



7 



July 25 

 July 26 

 July 28 

 July 30 

 Aug. 1 

 Aug. 2 

 Aug. 4 



Aug. 6 

 Aug. 7 

 Aug. 8 

 Aug. 10 

 Aug. 11 

 Aug. 13 

 Aug. 14 



15 

 20 

 38 

 13 

 18 

 19 

 22 



15 

 20 





37" 



12 



18 

 19 

 21 













Parasites placed with host August 4, having emerged August 3. New adults emerged August 30 to 

 September 3. Twenty-seven to thirty-one days to complete the life cycle. Root-worm eggs within two 

 to three days of hatching escaped parasitism. 



For each experiment egg clusters of the grape root-worm, each of 

 a given age, ranging from 1 to 10 days, were subjected to the para- 

 sites. The insects with the host were confined in large-size glass 

 vials, which were covered with fine cloth. In Table XXI it is probable 

 that the parasites oviposited shortly after being confined with the 

 host, since they had emerged a few days previous to their confinement 

 with fresh eggs. In the first experiment (Table XXI) the parasites 

 were confined three days with the hosts. The two experiments of 

 Tables XXI and XXII are practically identical, the second being made 

 to check the results with those of the first one. The records for the 

 normal hatching of the eggs are from another set of records, since 

 such data could not be obtained from parasitized eggs. The results 

 of either experiment show that the parasites did not affect eggs which 

 were within two or perhaps three days of hatching. There was 

 no marked difference in the time of the development of the parasites 

 from eggs of different ages. 



