124 SIXTH ANNUAL REPORT 



and describing, but the perfct fly (Fig. 34, rz, $ ), which may be called 

 the Unadorned Tiphia, issues in due course of time through a ragged 

 hole in the large or blunt end of its cocoon. 



From having repeatedly found the head parts of some Lamel 

 licorn larva attached to these cocoons, I had long suspected that 

 such larvae formed the food of this Tiphia, and on carefully examin- 

 ing these head-parts I recognized them as belonging to the common 

 White Grub. But all doubt as to this fly being parasitic on said White 

 Grub ceased when, in 1872, Mr. A. W. Smith, of St. Louis, brought me 

 a number of the cocoons which he had taken from a low part of his 

 farm on the Illinois bottom, where the White Grub was very thick, 

 and the yellow cocoons so numerous as to attract attention. 



The genuc Tipliia is characterized by having the maxillary palpi 

 long, and composed of unequal joints, and by the second joint of the 

 antenniTe being received into the first, which hides it. The insects be- 

 longing to it, like all fossorial or digger-wasps, are known to burrow 

 in the ground, but their larval habit has not heretofore been known. 

 Mr. Fred. Smith, of the British Museum, has surmised,* from certain 

 observations he made, that the European Tiphia femorata is para- 

 sitic upon ApJiodius — a genus of Lamellicorn beetles whose larvae re- 

 semble the White Grub in general appearance, and feed for the most 

 part on dung, entering the earth to transform. The surmise is doubt- 

 less correct, judging from the habit of our Unadorned Tiphia.f 



The parent fly must be endowed with a rare instinct to enable it 

 to find the under-ground food for its progeny, and consign therewith 

 an egg. Judging from analogy, she fastens this egg to the anterior 

 ventral part of the White Grub, where the latter'sjaws cannot reach 

 it; and her larva, with its head embedded, and clinging as tenaciously 

 as a bull-dog to the muzzle of a fated ox, feeds externally on its victim, 

 and, after rapidly appropriating all the softer parts, spins the cocoon 

 already described — the more horny head-parts of its prey naturally 

 adhering to the outside, or first-spun layer. The perfect insect issues 

 by gnawing, with its strong arcuated jaws, a hole near the blunt end 

 of its cocoon. 



The Unadorned Tiphia is polished coal-black in color, sometimes 



with a faint bluish hue, but without any paler markings. The body, 



> 



* Entomologist's Aunual, London, 1871, p. 57. 



t SfoZi'fl (the tj'pical "genus of the family), 2-cinc?a Fabr. , -which occurs both in this counti y and 

 Europe, makes its burrows in sand-banks, to the depth of eighteen inches, and is supposed to use the 

 Orthopterous locusts (Locustidcc) for tood—IVestw. Intr. II. p. 311. Scolia Jlavifroiis nttaches its egg 

 to the venter of the lai-va of a, common European Lamellicorn lan'a {Oryctcs nasiconiis) in the bark 

 beds (Vallonea) of hot-houses; and Passerini, as quoted by St. Fargeau (Hy7n. III., i)p. 504—517), de- 

 scribes its larva and cocoon, which are much like those of Tiphia, and explains how the latter must be 

 formed by the mature larva, as within it there are found no remains whatever of its prey. 



