416 U. S. NATIONAL MUSEUM BULLETIN 216 



articles, and technical papers. Most amateur insect collections 

 possess at least one specimen. The superficial aspects of their biology 

 have been described and discussed in many places. Some of the early 

 observations and speculation make interesting reading in the light of 

 our present information. 



An observation by Lintner (1889, Rep. New York State Ent., no. 4, 

 pp. 35-36) is an example. He stated that: "I recall an instance 

 observed by me several years ago, when what I think must have been 

 Bhyssa lunator, was earnestly engaged in placing its eggs in the fol- 

 lowing singular manner in a colony of a species of Datana, feeding 

 upon a branch of hickory: Its ovipositor was bent beneath it, extend- 

 ing between its legs, with its tip projecting in front of its head, en- 

 abling it with perfect ease to select one catepillar after another for 

 the reception of its eggs. Why would not this be a much better 

 method of using the long ovipositor than the one generally ascribed 

 to it? There would certainly be no hap-hazard work in such ovi- 

 position, or any waste of material. In the instance above recorded, 

 each thrust told, as was seen in the well-known alarm-jerk of these 

 larvae, at once communicated from the victim to the entire group." 



A more carefully reported observation was recorded by Walsh and 

 Riley in 1868 (American Ent., vol. 1, p. 77) from an article in the New 

 Orleans Christian Advocate, entitled "The Stiletto Wasp." The 

 article stated that: "The wasp was about one and a half inches long, 

 black and yellow, with a sting three and a half inches long, and as 

 large as a small needle; there were also two hair-like appendages of 

 similar length. One of the insects had struck at a boy several times. 

 Finally, making a desperate effort, the boy dodged behind a tree just 

 at the moment that the insect, throwing up its tail to strike, lost sight 

 of him and thus plunged the tail a full inch into a sweet gum tree, 

 from which it could not withdraw it. The father of the boy being 

 near with an axe, cut out a chip, and the sting was found to have 

 gone through it to the depth already stated." 



It is well known, now, that the species of Megarhyssa are para- 

 sitic on wood-boring Siricidae. In the bibliographies under the 

 species M. atrata and M. macrurus are references to many articles 

 which describe the interesting drilling operations of the female to 

 parasitize the hosts, the mating behavior, and some of the morphologi- 

 cal specializations. There remain, however, many unanswered bio- 

 logical questions, and the matter of the ecological separation between 

 M. atrata, M. macrurus, and M. greenei has not yet been touched upon. 

 All three of these are dependent on the same host, in the same geo- 

 graphic area, and frequently in the same tree or log, yet each one re- 

 mains moderately common and is not eliminated by competition with 

 its congeners. 



