20 Annals Efitomological Society of America [Vol. XII, 



genus of bees (Allodape) and in some ants. In connection with 

 some of these, Professor Wheeler has suggested to me that they 

 may be of assistance in eliminating the large amounts of water 

 ingested by rapidly growing insect larvae. Quite recently 

 Roubaud* has figured (p. 15) larvae of the remarkable Rhip- 

 iphorid beetle Macrosiagon ferruginea which are external 

 parasites of the wasp, Synagris. In these larvae the body is 

 covered with tubercles much like those of Psilogaster and 

 Perilampus. Roubaud also found in the larva of a Braconid 

 parasite occurring in the nests of Rhynchium, transverse welts of 

 apparently similar nature (/. c, p. 35, Fig. 14). In this case the 

 Braconid larv£e {Allodorus major) feed not upon the wasp 

 larvae, but upon one of the caterpillars used for provisioning 

 the nest. They develop at an unusually rapid rate, and on 

 this account may easily require additional facilities for excreting 

 water, particularly as they possess a closed alimentary tract 

 and must excrete all excess water through the skin. The 

 habits of a somewhat closely related genus of Braconidae, 

 Chelonus, have been described by Pierce and Holloway in 

 America. t This species is an internal parasite and undergoes 

 a much slower development, the larva requiring about three 

 weeks to mature. These writers do not describe the larva, 

 but it seems probable that they are not tuberculate, as such a 

 peculiarity would undoubtedly have been mentioned. It 

 seems probable, therefore, that at least one form related to 

 Allodorus, but developing more slowly, lacks the welts present 

 in Allodorus. This would appear to lend color to the suggestion 

 made above, that the welted or tuberculated integument may 

 function in excreting excess water. 



* Ann. Sci. Nat. Zool. 1916 Recherches biologiques sur les guSpes solitaires 

 et sociales d' Afrique. 



t Notes on the Biology of Chelonus texanus Cress., Journ. Econ. Entom., 

 Vol. 5, pp. 425-428. (1912). 



