ROTATION OF HOSTS. 49 
Important gaps exist in the host rotation of Catolaccus incertus. 
Its hosts breed as follows: 
Anthonomus signatus breeds from April 11 to June 12. 
Anthonomus fulous breeds from May 3 to July 12. 
Auletes tenuipes breeds from May 9 to May 25. 
Zygobaris xanthoxyli breeds from May 11 to June 29. 
Anthonomus xneolus breeds from May 17 to July 12. 
Anthonomus nigrinus breeds from June 30 to July 18. 
Anthonomus albopilosus breeds from August 26 to September 29. 
Anthonomus eugeniwi breeds from October 6 to October 31. 
Anthonomus disjunctus was found breeding October 11 to 14. 
The known habits of the hosts of Cerambycobius cyaniceps are as 
follows: 
Tylodernia foveolatum breeds from June 22 to September 23. 
Trichobaris texana breeds from June 26 to October 11. 
Lixus musculus breeds from August 11 to September 19. 
Anthonomus albopilosus breeds from August 26 to September 29. 
The following data comprise all that is known of the hosts of 
Eurytoma tylodermatis: 
Tyloderma foveolatum breeds from June 22 to September 23. 
Lixus scrobicollis breeds from July 12 to April 17 (following year). 
Anthonomus squamosus breeds from August 11 to September 19. 
Orthoris crotchwi breeds from August 11 to September 19. 
Lixus musculus breeds from August 11 to September 19. 
Anthonomus disjunctus was found breeding October 11 to 14. 
In the field at Dallas upon which release experiments were con- 
ducted, and in a series of five fields in various directions from Waco, 
it was found that the various species of parasites were exceedingly - 
localized, indicating that the parasites were derived from the imme- 
diate vicinity. 
On the Dallas field, by reference to the tables given in Section II, 
it will be noticed that Plat B with one small exception was the 
only plat in which Catolaccus was found; that Plat B was the only 
one from which Cerambycobius was bred; that Eurytoma was not 
found in Plat C, but was predominant on Plat E; and, finally, that 
Bracon was well distributed. 
At Waco on all five fields Bracon mellitor was present in the pro- 
portion of 20 to 50 per cent. On the prairie land field, surrounded 
only by Ambrosia, Helianthus, and Xanthium, 41.6 per cent of the 
parasites were Hurytoma tylodermatis. On the other fields, which 
were on the bottoms, only one Eurytoma was taken to a field. Cato- 
laccus incertus was present on the prairie land field and one bottom 
land field. Cerambycobius was present in all the bottom lands and 
very numerous, 58.3 per cent, in a field which had considerable 
Solanum rostratum about it; it was entirely absent on the prairie. 
The commonest plants on the bottoms were Heterotheca subazillaris, 
Croton spp., Solanum spp., and Xanthium. 
10292—Bul. 73—08——4 
