112 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



dopteryx ephemerceformis, Haw.), although Walsh (Trans. Acad. Sci. St. 

 Louis III, 137) identifies Say's Bombyx with Clisiocampa americana. 



Fig. 39. — Pimpla conquisitor : a larva; b head of do. from front; c pupa; d adult female (hair line in- 

 dicating natural size) ; e end of male abdomen from above ; / same from the side — all enlarged. (Orig- 

 inal.) 



The larva (Fig. 39 a) of Pimpla conquisitor is a legless maggot of a wMtisli col or, the 

 head well defined, concolorous with the body and with distinct mouth parts ; the tips of 

 the mandibles black. The body tapers posteriorly, the skin is hnely wrinkled, and no 

 spiracles are apparent ; the first three joints have a longitudinal, impressed line low 

 down on the sides, and the succeeding joints have a similar line higher up, and above 

 it a distinct lateral ridge or series of protuberances. The mandibles are slender and 

 pointed, situated beneath the labrum and above the three fleshy tubercles which 

 represent the maxillse and labrum. Above the labrum are two distant and very indis- 

 tinct circles with a minute point in the center, indicating the position of the anten- 

 nae. The largest larva examined measured 9"^^™. 



The 2mpa (Fig. 39 c) resembles the imago in the form of body, but the colors are unde- 

 veloped, the wings unexpanded, and the legs, antennae, and palpi laid along the sides 

 aiid breast. In the ^ the tip of the abdomen is abruptly terminated, and just before 

 the tip on each side is a tubercle bearing two projecting teeth ; in the $ the ovipos- 

 itor is curved up over the back. 



The species is widely distributed over the IJnited States and attacks 

 a large number of other lepidopterous larvae. It is probably the most 

 effectual as it is the most noticeable check to the development of the 

 chrysalis, and that it has always attacked Aletia seems most probable; 

 for the following account by Dr. Gorham, published in 1847 in the article 

 in De Bow's Eeview already cited, gives such an exact account of it 

 and such a full general description, that, while he could not name it, 

 there is no question as to its identity with the species under consider- 

 ation. In endeaving to explain the disappearance of the Cotton Worm 

 in early winter. Dr. Gorham writes : 



Let us take a pocketful of these [the chrysalides] horn© and place them beneath 

 tumblers, and wait patiently to see what they will produce. * * * About the 

 fifteenth of November the insect appeared, but, mirahile cUctu ! as different from the 

 Cotton fly as it is possible to suppose one insect could differ from another. It belonged 

 altogether to a ditterent family, a description of which I give as follows : 



Antennae filiform ; black, six lines in length. Palpi four, two external and two in- 

 termediate, the external white, twice the length of the other two, in shape angular, 

 the angles projecting externally. The two middle are straight, scarcely percejjtib.e 



