THE CANADIAN ENTOMOLOGIST 435 



ponding joint is but slightly broader than the preceding ones and 

 not as long as joints 3 and 4. 



4. In sinuata the basal portion of the vitta is nearly parallel 

 to the suture, and the middle portion very little or not at all 

 narrower than the distal, while in vittata the basal portion bends 

 towards the suture and the middle portion is decidedly narrower 

 than the distal. 



5. In sinuata the prothorax is twice as wide as it is long, 

 while in vittata its width is only about one-third greater than its 

 length. 



A SPECIES OF MEGASTIGMUS REARED FROM LARCH 



SEEDS.* 



BY S. MARCOVITCH, ITHACA, N. Y. 



On September 10, 1913, the seeds of the larch trees, Larix 

 laricina Du Roi, around the Cornell insectary, Ithaca, N. Y., were 

 found to be infested by a white larva. The seeds were kept in- 

 doors during the winter, and on April 2, 1914, the first adults of a 

 species of Megastigmus emerged. The larva completely devours 

 the kernel, and fills the entire seed making it difficult to open one 

 without injuring the larva. Examined on July 17, the larvae were 

 nearly two-thirds grown. That it feeds on the kernel as do all of 

 the known American forms of this genus is quite conclusive, since 

 only one kind of larva was found in the seeds. This species is 

 apparently undescribed. 



Megastigmus laricis, n. sp. 



Female. — Length 2.1 mm.; abdomen 1 mm.; ovipositor 1.6 



mm. General colour black; face, front nearly to base of the antennae 



yellowish; occiput, antennal grooves, and vertex, black; posterior 



eye-margin and cheeks, dark brown. Prothorax black, and finely 



rugulose. Anterior portion of mesonotum smooth, posterior part 



with fine transversely curved striae. Scutellum finely rugulose. 



Propodeum finely reticulate-punctate with a medium longitudinal 



carina, which is broken in the middle. Antennae brown, scape 



yellowish. Anterior coxae yellow; middle coxae brownish yellow; 



posterio r coxae black; rest of legs brownish yellow, except femora, 



"■Contribution from the Entomological Laboratory of Cornell University. 

 December, 1914 



