1915] 



Hyslop — Meracantha contracta {Beam'.) 



47 



the cage with the Meracantha while collecting. It killed its host 

 by eating into the thorax. Two weeks after pupation the first 

 adult emerged. When first transformed it was quite uniformly 

 cream white; the legs and pronotum soon became infuscate, then 

 brown and were followed by the elytra becoming darker. Finally 

 the entire beetle assumed the bronze black color of the mature 

 imago. 



One of the larvae that pupated on May 5 did not decay, as did 

 the other pupse that failed to becomes beetles, and on June 14 a 

 Bombyllid fly. Anthrax alternata Say.,^ emerged from it. The 

 pupa of this parasite is quite active just prior to the emergence 

 of the adult. It is provided with a row 

 of backwardly directed spines on the 

 dorsum of each abdominal segment, and 

 the dorsum of the terminal segment bears 

 four stout spines and is terminated by a 

 pair of prongs (Fig. lid). By alternately 

 flexing the body forward and backward, 

 the spines preventing any backward move- 

 ment of the sclerites, the pupa moves for- 

 ward. It pushed off the prothorax and 

 head of its host pupa (Fig. lie) and 

 protruded from the opening thus formed 

 (Fig. Ila) until the adult parasite emerged. 

 The head capsule of Anthrax (Fig. lib) 

 is armed with three pair of stout teeth 

 which probably assist in the act of emerg- 

 ing from the host. The adult Anthrax 



emerged from its chrysalis by forcing off the pupal head capsule 

 and splitting the dorsum of the pronotum. How this parasite 

 locates the larvae of Meracantha, which never come above ground 

 as far as I have observed, where she oviposits, and the period the 

 parasite spends within its host still remains to be determined. 



In August of the same year I again made observations on 

 Meracantha contracta. On this occasion I was collecting the 

 larvae of Sericosomus viridanus Say. from under the moss, Pcly- 

 irichum ohioensis, on the top of the same mountain range but near 



Fig. 2. Meracantha contracta. 

 Pupal case and pupal case of 

 parasite. Anthrax alternata. 



1 Determined by Mr. W. R. Walton. 



