54 



INSECT ENEMIES OF THE BOLL. WEEVIL. 



(Capsicum spp.); Anthonomus fulvus Le Conte in buds of Callirrhoe 

 involucrata; Anthonomus squamosus Le Conte in heads of Grindelia 

 squarrosa nuda; Conotrachelus nenuphar Herbst in peaches ; Tyloderma 

 foveolafum Say in stems of Onagra biennis; Craponius inxqualis Say in 

 fruit of grape ( Vitis spp.), and Baris sp. in roots of Ambrosia sp. 



6. BIOLOGICAL NOTES UPON THE PARASITES OF THE WEEVIL. 



A number of very interesting facts, wliich deserve mention in an 

 economic bulletin, have been learned about the biology of the parasites. 



ABUNDANCE OP PARASITES. 



It is unusual for the parasites of the boll weevil to be found fl}^ng 

 in numbers. Their work is in a general way quietly and unostenta- 

 tiously done, but occasionally it is the privilege of the observers to 

 see swarms of parasites hovering around the food plant of their 



favorite host. At Clar- 

 endon, Tex., in August 

 and September, 1905, Mr, 

 C. R. Jones and the sen- 

 ior author witnessed large 

 numbers of Microbracon 

 nuperus and TetrasticJius 

 sp. hovering around the 

 highly infested pods of 

 Mentzelia nuda. The par- 

 asitism in pods gathered 

 at this time was so high 

 that much superparasit- 

 ism by Tetrastichus upon 

 theMicrobracon occurred. 

 At Ruston, La., in Octo- 

 ber, 1907, the senior 

 author saw Catolaccus 

 Tiunteri flying in all directions and resting on the flowers and 

 leaves of Heterotheca subaxillaris and found a very high parasitism 

 of Anthonomus heterothecx by this species. In November, 1908, 

 in this same field at Huston, a very high percentage of parasitism 

 of the boU weevil by Catolaccus was found. In September, 1908, 

 Mr. Hood saw many species of parasites around the flower heads 

 of Vernonia at Camden, Ark, During the same month Mr. H. S. 

 Smith found Catolaccus hunteri swarming on Croton capitatus contain- 

 ing Anthonomus albopilosus. Such observations are very important 

 because they suggest excellent sources for parasites to be used in 

 introduction experiments or suggest forcing of the parasites to the 

 boU weevil by the elimination of the host. 



FiG.12.— Microbracon mellitor: Adult. Much enlarged. (From 

 Hunter and Hinds.) 



