510 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



always placed by the mature larva around the cocoon site. To the 

 finest imaginable detail these bristles exactly simulate the hirsute 

 pubescence to be found on the stems and petioles of most cultivated 

 cotton varieties. In length, color, general shape and even in the bar- 

 bellate character of the hairs the similarity is complete. On the other 

 hand, the Thurberia plant is of an almost glabrous nature, and the 

 sparse pubescence which at times is found on the stems bears no simi- 

 larity to the stockade bristles of the Bucculatrix cocoon. If, as they 

 doubtless are, these protective hairs are intended to imitate the pub- 

 escence of the native host, the Thurberia plant — by this test — should 

 at once be eliminated. 



From the foregoing arguments it seems very probable that the 

 Bucculatrix under discussion was originally a native pest of Gossypium 

 species. If this is true it follows that the insect has found its way to 

 the United States from the ancient cotton-growing areas of Mexico 

 and from the insular and maritime regions of tropical America to which 

 cotton is indigenous. In this respect is would constitute a case some- 

 what parallel to that of the cotton leaf worm (Alabama argiUacea). 



Explanation of Plates 36 and 37 



Fig. 1. Severe infestation of Bucculatrix thurberiella on young, backward cotton. 

 (Cocoons on stems indicated by arrows.) 



Fig. 2. Perforating effect of the pest on the apical foliage of tall cotton. 



Fig. 3. Pupal cocoon of Bucculatrix thurberiella on stem of cotton plant. XlO. 



Fig. 4. 15-inch cotton plant showing perforations and dessication resulting from 

 the work of larvae of Bucculatrix thurberiella. 



Fig. 5. A 10-inch seedling cotton plant which has been severely injured and 

 retarded by tbe presence of Bucculatrix larvae. 



The Hyperparasitic Chalcidoid Planidium on Aphides. October 13, 1915, the 

 writer collected a male specimen of Aphis pomi DeG. on an apple tree in the 

 orchard of the Virginia Agricultural Experiment Station, Blacksburg. The speci- 

 men was found to possess what appeared to be a supernumerary appendage in the 

 form of a cone-shaped, segmented body or structure which arose from the head, at 

 the base of one of the antenna?. On the supposition that this body might be a 

 parasite, the specimen was sent to Prof. Roland Thaxter of Harvard University, al- 

 though it did not appear to be of a fungous nature, for examination, with the request 

 that he forward it to Prof. W. M. Wheeler of Bussey Institution, Forest Hills, Mass., 

 with whom the writer had had some correspondence regarding the significance of 

 the body, in case he did not find it to be a fungous parasite. The specimen was for- 

 warded by Professor Thaxter to Dr. Wheeler who identified the body as the first 

 larval stage, or planidium, of a Chalcidoid hymenopteron, the type of larva which 

 was discovered by him on ant larva; in Texas. (See Bui. Am. Mus. Nat. Hist., Vol. 

 23, Art. I, 1907; also "The Chalcidoid Genus Perilampus, etc.," by Harry S. Smith, 

 Tech. Ser., No. 19, Pt. IV., U. S. Dept. of Agr., 1912.) 



The occurrence of such larvae on Aphides seems not to have been reported before. 



M. T. Smulyan, Virginia Agricultural Experiment Station 



