1913] North American Species of Megastigmus. 157 



Through the kindness of Mr. A. G. Hammar I received 

 some Sorbus berries from Sweden from which 5 females were 

 reared. In these specimens the head is black with the face 

 dark honey-yellow. Pro thorax honey-yellow, rest of thorax 

 black. Antennae very much darker than in the type. Abdo- 

 men black with brownish bars on the sides. Rodzianko states 

 that he has never been able to rear the male. 



I have reared this species abundantly from the seeds of 

 Sorbus in New York State. The American specimens are 

 slightly smaller than those from Europe and vary greatly in 

 color, but I have been unable to find any constant character 

 by which they may be separated. The darker individuals are 

 very close to the typical form. A large proportion of the speci- 

 mens are of uniform brownish yellow. The legs are light 

 yellow and the antennas and ovipositor are brownish. Between 

 these and the typical form all gradations occur. 



Male. — Length, 1.7 to 2.1 mm.; abdomen, .7 to .8 mm. All the 

 males reared are much darker than the females. The face and cheeks 

 are yellow; the legs dull yellowish and the antennas more yellowish than 

 in female. Head and thorax black except a small spot on each side 

 between the ocelli and the eyes and an area on the lateral aspect of the 

 prothorax, which are brownish yellow. Stigmal club surrounded by 

 a very narrow clouded area. 



Abdomen compressed, seen from the side, elongate triangular, 

 rounded behind, brown-black above and yellowish brown beneath and 

 at apex. 



The larva is white, and its mandibles have four teeth on the 

 inner margin. 



In addition to rearing the adult insect at Ithaca, infested 

 berries of the Mountain Ash have been found at Weedsport, 

 Janiesville and Wayland, N. Y. 



In the' National Museum collection is a female specimen 

 from Mt. Washington bearing Ashmead's manuscript name 

 Megastigmus slossonce which agrees exactly with the lighter 

 specimens reared from Sorbus seeds from New York State. 

 In the National Museum there is also a very dark 9 from 

 Oswego, N. Y., 1 July, 1897. 



As suggested by Mayr. (Verb, zool.-bot. Ges. Wien, 

 XXIV, p. 139. 1874) this species may be the same as M. bi- 

 punctatus Boheman. 



