32 



PARASITES OF THE COTTON BOLL WEEVIL. 



Table XIX. Th seasonal distribution of tht parasites — Continued. 



Locality. 



Date. 



Bracon 

 Total mellitor. 

 num- 



Catolaccus 

 incertus. 



Eorytoma 



tvlouVrma- 

 tis. 



Ceramby- 



cobius cy- 

 aniceps. 



Sltcs - ber. 



Per- 

 cent- 

 age. 



Niun- 

 Der. 



Per- 

 cent- 

 age. 



Num- 

 ber. 



Per- 



• ■• ■ i- 

 age. 



Num- 

 ber. 



Per- 

 cent- 

 age. 



Victoria, Tex 



1906. 

 June 16 



„ 















Do 



June 23 



9 5 

 11 2 

 20 10 

 33 15 

 24 



18.0 



38.4 

 45.4 



2 



6 



7 

 8 



54. ■". 



24. 2 











Do 



June 25 











Do 



June 26 











Do 



June 27 



1 



3.0 







Do 



June 28 







Do 



July 2 



July 5 



Julv9 



24 . . 

















Do 



19 

















Do 



13 3 



23.0 

 56.2 

 60.0 

 60.0 

 32.0 

 20.0 

 54.2 

 56. 1 

 52.7 















Do 



July 18 32 18 



2 



6. 2 



1 



3.1 







Do 



July 22 



5 3 







Do... 



September 1 



July 25 



75 45 

 78 25 

 5 1 

 83 44 

 114 64 

 36 ! 19 

 31 



3 



6 

 1 



4.0 



7.6 



20.0 



3 

 3 



1 

 7 

 3 

 8 



4.0 

 3.8 



20.0 

 8.4 

 2.6 



22. 2 



11 

 4 



14. 6 



Waco, Tex 



5 1 



Do 



August 17 





Do... 



August 28 



25 



12 

 20 



29.8 



Do 



Anenist. 29 



11 

 2 



9.6 

 5.5 



10.5 



Do September 19 



Do October 12... 



.">.">. 5 























These figures show very plainly the range of each species and 

 have therefore been used to form a map of the two predominant 

 species throughout the State. The centers of the areas predominated 

 by Catolaccus are Brownsville, Tex., and Orange, La. The influence 

 of Bracon radiates from Goliad and Corsicana, Tex. The center of 

 predominance for Cerambycobius is Marshall, Tex. Eurytoma 

 becomes an active agency at Dallas and Overton, Tex. 



BIOLOGICAL NOTES ON THE PARASITES. 



1. Micnodontomerus anthonomi Cwfd. The Torymidse have always 

 been considered by Dr. William H. Ashmead as parasitic on Diptera. 

 In addition to the records of parasitism upon the boll weevil, which are 

 given on a preceding page, one other specimen was bred September 

 13, 1905, at Mexia, Tex., by F. C. Pratt from Brachytarsus diterrvatus 

 Say, breeding in the stems of Sideranthus rubiginosus. The species 

 is not at all abundant, and has only been collected in cotton forms 

 between August 28 and September 3. It is perhaps a one-genera- 

 tion species, although it may have some other and still unknown 

 host. There is but one individual to each host, and the host may 

 be in the larval or pupal state when attacked. The sexes occurred 

 in the proportion of 2 males and 11 females. 



In order to ascertain the length of the developmental periods, the 

 following scheme had to be used: The maximum period from col- 

 lection to maturity is the nearest approach possible to the total 

 developmental period, and next to this is the total period in a Bracon 

 cocoon in case of hyperparasitism. The maximum period from the 

 observation of the larva to maturity is the nearest approach possible 



