120 AMERICAN HYMENOPTERA. 



species I am unable to decide this. Though not mentioned 

 by Cameron there are two specimens of this species which 

 bore the MSS. label '' Personatus Cameron " in the Biologia 

 material at the British Museum. 



Distribution. — This species ranges from southern Canada 

 into Mexico and Central America. It has been taken in Stone- 

 wall, Manitoba, and Quebec, Canada ; Maine, Pennsylvania, 

 Florida, Texas, Ohio, Arizona, Kansas and Colorado, besides 

 many other places within these limits. Morley states that 

 it is quite common in Central America. 



Life history and habits. — This, the most common member 

 of the genus in the United States, will be found in almost 

 any large collection. It is diurnal, and frequently seen in 

 July and August along wooded roads, darting every now 

 and then into the underbrush or flying among the blossoms 

 by the roadside. In Massachusetts it appears about the 

 twentieth of June, but does not become abundant until the 

 second week in July, when it continues so till the last of 

 August. It has been taken as early as March 27 and as late 

 as October, but it appears throughout its range to be most 

 abundant in July and August. The eggs are laid as usual, 

 and the pupae formed in the earth outside of the host. Mrs. A. 

 K. Dimmock states (in litt.) that " in one or two cases, where 

 the host larva was left without earth, the 77zy;-<?c»^(7;z larva came 

 out of it for pupation. T. w^r/t? always hibernates as a pupa, 

 and all of its pupations which have been observed occurred 

 in September." The cocoon is compressed oval, 19-20 mm. 

 long and 10 mm. broad, composed of black silk compactly 

 glued together. 



Economic importance. — The abundance of this parasite indi- 

 cates that it is quite beneficial, especially as it is always fatal to 

 its host, but thus far only two hosts have been reported. There 

 is in the U. S. National Museum a specimen bred from Lapara 

 {Sphinx) coniferar2i7n, and Mrs. A. K. Dimmock reports a 

 case at Cambridge, Mass., where out of thirty larvae of 

 Paonias {Smerinthus) exccecatus Abb. and Sm. eleven were 

 killed by this parasite, and another at Canobie Lake, N. H., 

 where four out of 26 cocoons of the same insect were paratized 



