EXPERIMENT STATION BULLETINS. 



275 



cocoon in some hiding place Or between the leaves. The pupa is not 

 especially peculiar except that it has a very large broad thorax and 

 abdomen. 



The Imago. The female white pine saw-fly (Fig. 6) comes in June to 



lay her eggs. She is brown, 

 though often the margin of 

 the thorax and the sides of 

 the abdomen are more or less 

 marked with black. The eyes 

 and ocelli are dark, and the 

 antennae are black and pectin- 

 ate. The length of the female 

 is eight mm. (.32 inches,) and 

 about one half as broad. The 

 male is black, except the legs, 

 which are a light yellow, and 

 the tip and under side of the 

 abdomen, 

 fig. 6. which are 



light brown. It is smaller than the female, being only* 

 six mm. (.24 inch) long. The antennae of the male (Fig. 

 7) are very broadly pectinate; there are seventeen of the fig. i. 



nftMirptinno Antenna of male great- 



pectmations. ly magnified. 



WHITE PINE SAW-FLY PARASITE. 



This insect is greatly held in check by a 

 beautiful chalcid fly, (Fig. 8,) Perilampus 

 hfyalinus, Say. We append the original 

 description: Green; wings hyaline; inhabits 

 Pennsylvania; body green, punctured; scutel 

 much elongated, slightly emarginated; wings 

 hyaline, immaculate; abdomen very short, 

 wide, triangular, very convex above and 

 beneath, violaceous; tarsi yellowish; anterior 

 tibiae honey yellow ; length less than one fifth 

 of an inch. Differs from the P. triangularis 

 in being destitute of the dusky wing-tips, and 

 in having punctures instead of striae. 

 Those that we have reared agree very closely with Say's description. 

 We would only add antennae, eyes and claws black; veins of wings brown; 

 knees and distal half, more or less, of middle and posterior tibiae, honey 

 yellow. We have reared these in the laboratory in April, and also in 

 June and July. This is one of our largest and most beautiful chalcid flies. 

 While this article has been written wholly by Prof. Cook, so much of 

 the work has been done by Mr. Gr. C. Davis that the plural pronoun has 

 been used when possible. So much and so valuable has been Mr. Davis' 

 part in the work that he very justly appears as joint author. The draw- 

 ings, except figures 5, 6 and 7, were made by Mr. Gr. C. Davis, No. 5 by 

 Mr. F. J. Niswander, and Nos. 6 and 7 by Mr. C. F. Baker. 



A. J. COOK, 

 Agricultural College, Mich. ) Gr. C. DAVIS. 



June SO, 1891. 



Fig. 8. 



