Clje faabian Entomologist. 



VOL. XL LONDON, ONT., SLPTEMBER, 1879. No. 9 



PARASITES OF THE COTTON WORM. 



BY PROF. C. V. RILEY, WASHINGTON, U. S. 



Among the parasites so far found to attack and destroy Aletia argillacea 

 Hubn., aside from two not reared to the perfect state, are the following : 

 Obtained from the egg, Trichogramma pretiosa n. sp. ; from the larva, 

 Tachina aletia n. sp., and Sarcophaga sarracctiice Riley ; from the pupa, 

 Pimpla conquisitor (Say), Cryptus nuncius Say, Chalcis ovata Say, and 

 Cirrospilus esurus, n. sp. 



I append descriptions of the new species, in order that they may be 

 properly referred to by Prof. J. H. Comstock, who is now finishing the 

 report on the Cotton Worm begun by me while connected with the 

 Department of Agriculture. 



1. Trichogramma pretiosa, n. sp. — Length about 0.3 mm. Yel- 

 low, the eyes red, the wings hyaline. Head wider than the thorax ; 

 antennae 5-jointed, joints 3 and 4 in the % forming an ovate mass and 

 together shorter than joint 2 ; joint 5 large, thickened and very obliquely 

 truncate ; in the £ joints 3, 4 and 5 form a more or less distinct, elongate 

 club, beset with long bristles. Hairs of the wings arranged in about 

 fifteen lines. Abdomen not so wide as the thorax, but as long as the head 

 and thorax together; in the £ the sides subparallel, and the apical joint < 

 suddenly narrowed to a point. Described from numerous specimens 

 reared from eggs of Aletia argillacea. 



Differs from Trichogramma minuta Riley (Third Rep. Ins. Mo., p. 

 158, fig. 72, °. ) in its smaller size and uniform pale yellow color, and also 

 in the luim of the third and fourth joints of the antennae. As defined 

 and figured by Westwood, the antennae of Trichogramma are 6-jointed. 

 Walker, in his "Notes on the Chalcidia?," pt. vi., p. 105, employing 



