102 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



Infesting and issuing from the chrysalis: 

 (8.) Pimxjla conquisitor Say. 

 (9.) Fim'pla annulipes Br. 

 (10.) Cryptus nuncius Say. 

 (11.) Chalets ovata Say. 

 (12.) Cirrospilus esurus Eiley. 

 Species issuing from the chrysalis and not true parasites of Aletia, 

 though easily mistaken for such : 

 (13.) Hexaplasta zigzag Eiley. 

 (14.) Phora aleiice Comstock. 



Infesting and issuing from the Egg. — The Trichogramma Egg-parasite.— 

 [Trichogramma 'pretiosa Eiley )^^: Attacking Aletia in its earliest state, 

 the unhatched ^g^^ this winged atom must be, when abundant, a 

 most effectual check, and the scarcity of the Cotton Worm in certain 



seasons may doubtless be i^artly 

 ascribed to its work. It is at 

 least known that a similar egg- 

 parasite has in the Xew England 

 States relieved the shade trees 

 from the ravages of Canker- 

 worms — a good deed which the 

 European sparrows, notwith- 

 standing they received the 

 credit for it, were unable to ac- 

 complish. This Trichogramma 

 is a yellow fly, so small that 

 were it not for its activity in 

 jumping it could not be distin- 



FiG. 2,1.— Trichogramma preiiosa: a, female; &, tip of guislicd bv the Unaidcd CVC aS 

 female abflomen ; c, female autenua; d, male antenna (all . > n -i 



greatly enlarged). (Original.) au animated being, aud it fiuds 



sufficient nourishment in a single ^gg. of the Aletia to support its growth 

 and maturation. It emerges from a roiind hole 'which if gnaws through 

 the egg-shell, and eggs infested by it or which have been destroyed by 

 it may be recognized by their bluish or blackish color or the presence 

 of this perforation. When examined under the microscope, the perfect 

 fly is found to be an object of much beauty, the hairs upon the wings 

 being arranged in regular lines. Some .specimens of both sexes — the 

 male may be distinguished by the bristly antennae — were found to have 

 one or more of the wings imperfectly developed, presenting the appear- 

 ance of a i)addle. The accompanying figure (Fig. 31) will serve to illus- 

 trate its character and render further description unnecessary. 



This minute creature was first noticed by Professor Comstock in 1878, 

 near Selma, Ala., and in October, 1879, we found it quite common in 

 Mississippi, Alabama, and Georgia, fully one-fifth of the eggs in some 

 fields being infested. Mr. Schwarz found it rather rare in Texas, and 



