ZEXILLIA AND ALLIED GENERA — SELLERS 55 



Howard and Ftske, U. S. Dept. Agr., Bur. Ent, Bull. 91, pp. 91, 92, 136, 



257, 2S6, 297-300, 310, 1911. 

 Carcelia laxifrons Yii.nrcNEuvE, Feuille Jeun. Nat., sor. 5, vol. 42, pp. 42, 90, 



1912.— Baee, Zeitschr. Angew. Ent, vol. 7, p. 142 (108), 1921.— Thompson, 



Bull. Biol. France et Belgique, vol. 57. tV.se. 2, p. 185, 1923; Ann. Parasitol. 



Humaine et Compar., vol. 4, No. 3, 1926. — Cbossm an and Webber, Journ. Econ. 



Ent., vol. 17, p. 69, 1924.— Lundrf.ck. Diptera Danica, pt. 7. p. 380, 1927.— 



Btjegess and Crossman, IT. S. Dept. Agr. Tech. Bull. 86, pp. 130-13S, 1929 — 



Thokpk, Biol. Rev., Cambridge Phil. Soc, vol. 5, No. 3, pp. 193-194, 1930. 

 ZrniJJi'f cheloniae of Aldetcu and Webber (nee Rondani), Proc. U. S. Nat. Mus., 



vol. 63, art. 17. pp. 31-32. 1924. 

 ParaexorU a laxifrons (Villeneuve) Townsenb, Manual of myiology, pt. 4, 



pp. 211-213, 1936. 



This species was introduced into the New England States under 

 the name Parexorista cheloniae (Rondani) and resembles very clos 

 Carcelia malacosomae, which was considered previously also to be 

 Exorista or Parexorista cheloniae (Rondani). All the known differ- 

 ences are cited in the key to the species. 



Distribution. — Widely distributed throughout Europe. Carcelia 

 laxifrons has become established in New England. It has been re- 

 covered from many localities over practically the whole area in- 

 fested by the brown-tail moth in Maine 2, New Hampshire 1, Massa- 

 chusetts 8, and many other localities. 



Hosts. — Nygmia phaeorrhoea (Donovan) 157; Malacosoma ameri- 

 cana (Fabricius) 6 specimens bearing Gypsy Moth Laboratory note 

 numbers, and 41 specimens labeled as being from this host but bear- 

 ing no note numbers; Malacosoma disstria Hiibner 5; Porthetria 

 clispar (Linnaeus) 2. Lundbeck has published a European host rec- 

 ord of Dasychira fascelina (Linnaeus) (Larsen). 



Remarks. — The material examined consisted of 51 exotic specimens 

 from Europe mostly reared from the brown-tail moth; 211 reared 

 specimens bearing Gypsy Moth Laboratory note numbers except as 

 indicated; 4 specimens bearing miscellaneous numbers from the 

 Gypsy Moth Laboratory; one male labeled only "ex M. americana" 

 removed from the Sisyropa "eiidryae" material; one male with pu- 

 parium labeled as paratype of Carcelia reclinata, U.S.N.M. No. 25697, 

 Gypsy Moth Lab. VI-16-16 ; and 28 field-collected specimens. Prac- 

 tically all the above-mentioned specimens had been identified as 

 Zenillia " cheloniae, ," 



The value of Carcelia laxifrons as a parasite of Nygmia phaeor- 

 rhoea in New England is highly dependent upon the climate, which 

 on the average is more unfavorable because of its severity than in its 

 more favored range in Central Europe. In this connection, it should 

 be recalled that C. laxifrons emerges earlier in the spring than Car- 

 celia malacosomae. Some of the most outstanding recoveries from 

 the standpoint of numbers have been made from the Massachusetts 



