RILEY ON A NEW GENUS IN MELOID.E. 563 



On a remarkable new Genus in Meloid.^ infesting Mason- 

 bee Cells in the United States. 

 By Charles V. Riley. 



[Read Nov. 5, :377.] 



While the natural history of none of our N. A. species of Meloe 

 has been traced or recorded, they will, beyond all doubt, be found 

 to agree with their European congeners in their partial parasitism 

 on Mason-bees. In examining the cells of Anthophora sponsa, 

 Smith, I have so far failed to discover that Meloc is parasitic 

 upon that species, but Meloc is, in reality, very rare around St. 

 Louis. I have, however, found on four different occasions in 

 the Fall, within the sealed cells of the bee mentioned, a very 

 interesting and anomalous Meloid which may be taken to repre- 

 sent the typical partial parasitism of the family in the United 

 States. There is a tendency in the family to wing reduction, but 

 in no hitherto described species is the reduction carried to such ex- 

 tremes as in this, both sexes (PI. V., Fig. 13) having the elytra as 

 rudimentary as in the $ of the well-known European Glow-worm 

 {La/npyris noctiluca). Another characteristic feature is its 

 simple tarsal claws, which, together with the rudimentary wings 

 and the heavy body, show it to be a degradational form. 

 Anthophora sponsa, its host, builds mostly in steeply inclined or 

 perpendicular clay banks, and, in addition, extends a tube of clay 

 from the entrance. The burrow has usually two branches which 

 decline about an inch from the surface of the bank, and 6 or 8 

 cells are arranged end to end. By means of saliva the inside of the 

 cell is rendered impervious to the moisture of the honey and bee- 

 bread stored in it for the young, It is evident, therefore, that this 

 clumsy Meloid will have difficulty in crawling out of or about 

 the cells, and it is probably subterranean and seldom, if ever, 

 leaves the bee gallery. It can climb and drag its body, but 

 with some difficulty, up a steep surface, and, as it does not 

 leave the bee-cell till spring, when the Anthophora tubes are 

 very generally broken and have fallen, it may possibly wan- 

 der a short distance from the mouth of the bee-burrow. The 

 triungulin is yet unknown, but the ultimate stage of the second 

 larva as well as the coarctate larva, as shown by the distended 

 and unruptured skins, exhibit the ordinary family characteristics, 

 the legs and mouth-parts being atrophied in the former, and 



