NOTES ON THE BIOLOGY OF RELATED WEEVILS. 43 



what was supposedly the same species from Helianthus in Kansas. It 

 oviposits in the bud or flower at the base thru the involucre. The 

 presence of the weevil is indicated by the blackening of the two or 

 three punctured involucral bracts. The larva feeds among the ovaries 

 in the flower head and forms a compact cell from its exuviae. This 

 cell is the more compact because of the sticky nature of the flower. 

 Here it pupates and matures, the adult emerging from the dry seed 

 head. The specimens secured differ greatly in size, color, and vestiture. 



PARASITES. 



Bracon raellitor Say was bred in large numbers from the larvee. 



Eurytoma tylodermatis Ashm. was bred in large numbers as a pri- 

 mary parasite. 



Catolaccus sp. One specimen of this genus was bred, and is pre- 

 sumably a primary parasite. 



An undetermined noctuid caterpillar, which eats out the heads of the 

 Grindelia, destroys all weevils breeding in the flowers it attacks. 



LIXUS MUSCTJLUS Say. (PI. I, figs. 1, 2.) 



This species was found by Mr. C. R. Jones and the writer breeding 

 in considerable numbers in the stems of Polygonum jpennsylvcmicxiin 

 at Clarendon, Tex. It oviposits near the joints of the stem, and the 

 young larva as it feeds causes the stem to enlarge and form a gall -like 

 cell. These galls are twice the diameter of the stem and about three- 

 quarters of an inch long. The growing weevil fits its cell tightly, and 

 consequently, after maturing, it takes some time for it to gain an exit. 

 The adultignaws a round hole in front of its head and then gradually 

 forces itself out. 



PARASITES. 



Glyptomorpha {Bracon) rugator Say. One adult was bred from the 

 weevil and numerous pupse were found in the cells. The pupa is 

 inclosed in a brown papery cocoon, which completely fills the cell and 

 crowds the remains of the Lixus against the wall. 



Ewytoyna tylodermatis Ashm. was bred as a primary parasite. 



Neocatolacciis tylodertride, Ashm. was bred as a primary parasite. 

 This species has been bred also from boll-weevil-infested squares. 



Cerainbycobius cyaneiceps Ashm. One specimen was bred from an 

 infested stem, and is probably a Lixus parasite. 



Eurytoma tylodermatis Ashm. One individual bred from an infested 

 stem and probably a parasite of Lixus, tho perhaps hyperparasitic. 



A p3^ralid larva which dwells in the stems of this plant seems to be 

 ver}^ fond of this weevil, as it not only eats those which lie in its path 

 but has been frequently seen to cut a hole into the galls from the outside 



