ORDER HYMENOPTERA. 



Ichneumon . ( Plate xxvil, fig. 7.) 



Color black. Scutel yellowish, with a sharp ridge extending from the anterior angle to the 

 base of the wing. Second and third abtlominal rings orange, with the posterior part of 

 the second black upon the top : beneath, the orange color covers the entire rings. 

 Face and legs orange ; the face pale. Antennae entirely black. Wings transparent, and 

 only slightly smoky. 



Ichneumon . ( Plate xxvii, fig. 9.) 



Color black. Wings smoky brown. Antennae with a white annulus beginning about the 

 sixth ring from the base. 



PiMPLA LUNATOR. (Plate i, figs. 1, 2, 3, 4, 5, 6.) 



Antennae brown, darker at base. Eyes black. Head brown, encircled with a ring of two 

 yellow bands, and one of a pale brown : front yellow, with a brown band extending 

 Irom one eye to the other. Thorax brown, marked upon the top by a trident, or a 

 longitudinal band terminating before in three divaricating lines. Laterally there are 

 two broad brown bands parallel with the first : between the wings, the middle band 

 divides and forms a circle, the inside of which is yellow. Abdomen compressed, sabre- 

 form and narrowed before. The seven rings of the abdomen are marked by semilunate 

 bands at their posterior margin, and succeeded by a black ring : the lateral parts of 

 the rings form an acute arch in the female, which enables her to flex the abdomen as 

 represented in fig. 4. Abdomen greatly dilated at its extremity in the female, and 

 terminated by a greatly elongated ovipositor. Wings transparent, and marked by a 

 brown patch. In the male, the abdomen is slender. Legs yellow and light brown. 

 The female is sometimes 1 ^ inch long, with an ovipositor some three inches long. 



Fig. 4 : Female in the act of introducing its ovipositor into the trunk of a maple tree. 

 Figs. 1 & 6 : Males. 

 Fig. 5 : Female at rest. 



The yellow bands represented as lunate, are probably too sharply arched to admit strictly 

 of the appellation. 



This insect formerly frequented a half-grown maple in the yard of the State House in 

 this city. I supposed at first that the pimpla was attracted to this tree, in consequence of 

 the sirer having also made it the place for depositing its eggs. The larvse of both insects 

 were found in great numbers in difiierent stages of growth ; but it did not appear that the 

 larvse of the former fed upon those of the latter, for they were both in many instances full 

 grown and separate. In some cases the pimpla passed her ovipositor very near to a larva 

 of the sirex ; but it could not be ascertained, after a very careful examination, that the 

 object of the first was to pierce the larvai which infested the tree, alter the manner of 

 ichneumon-flies. Still the habits of the family favor the view that the larvae of the pimpla 



