some British Guiana Hymenoptera. 311 



M. nUjriceps, Spin. One of the commonest species of 

 Hymenoptera on the coast lands. Also a species of par- 

 ticular economic value, as it hunts for and destroys the 

 larvae of many agricultural pests, including the Rice Worm 

 [Laphygma frugiperda, S. & A.) and the Para-grass Worm 

 {Mods repanda, F.). This wasp may frequently be seen 

 searching for its prey amongst grass and tall rice. A large 

 pendant, irregularly-shaped nest is formed, which is some- 

 what fragile in its structure. These nests contain a large 

 and active community. 



M. infernalis, Spin. An uncommon species on the coast 

 lands. According to C. B. Williams, who has observed 

 the habits of this wasp, it constructs burrows in the clay 

 banks of the canals or trenches to be found on all sugar 

 estates. Green caterpillars are stored up in the nest, and 

 an egg is deposited, which is hung from the roof of the 

 burrow by a long stalk. The opening of the burrow is 

 small in comparison with the size of the wasp. 



M. infundihidiformis, F. Issororo, N.W.D. 



Genus Eumenes, Latreille. 



E. canaliculata, Oliv. An exceedingly common species 

 to be met with mostly on the coast lands. Its dome- 

 shaped mud cells, in small colonies of five or six and some- 

 times more, are objects of common observation attached 

 to the rafters beneath houses and in sheltered spots on 

 walls and palings. These mud cells (see photo) are usually 

 about I inch in height and with a diameter of about | inch. 

 Some cells possess a kind of " neck " at the top of the 

 cell, giving it the appearance of a squat-shaped earthen 

 bottle. These cells are stored with Lepidopterous larvae 

 usually slightly over an inch in length and, of course, 

 paralysed by the sting of the wasp at the time of capture. 

 From four to six such larvae are stored. The wasp larva 

 becomes mature in ten days to two weeks from the time 

 of emergence from the egg. The pupal stage lasts slightly 

 over a week. The adult wasp emerges from the cell by 

 biting a circular hole in one side. These empty cells are 

 afterwards utilised by a species of Trypoxylon for its nest, 

 and stored with spiders. A small species of black ant 

 {Cremastogaster, sp.) finally colonises these disused cells. 

 In constructing such cells the adult wasp holds the piece 

 of moist and plastic mud in position on the half-constructed 

 nest by means of the two front pairs of legs, and the deli- 



