SOLITARY WASPS OF GENUS SYNAGRIS ROUBAUD. 509 



found by the side of the young larva of Synagris were identified by 

 Mr. P. Chretien as those of hesperids. By means of these remains it 

 is possible to describe the habits of the wasp. It deposits in the cells 

 during the course of their construction a hoard of caterpillars, ren- 

 dered immovable, and an egg, and then walls up the orifice, and takes 

 no farther care of its offspring. This is the ordinary ' provision of 

 food as found among other solitary wasps. Mr. Maindron, 1 more- 

 over, observed in 1879, at Senegal, the mode employed by S. calida 

 in providing food. He saw the insect hunt about small bushes, 

 seize upon caterpillars, grasping them with its mandibles and pierc- 

 ing them with its sting, and then carrying them away and storing at 

 least six in each cell. In the Brazzaville nest the number was much 

 larger. I counted as many as 14 caterpillars in the same cell. Many 

 of them were parasitized by the larvae of a Tachina (T. fallax Meig. 

 = T. xanthaspis Wiedm.= Eutachina wiennertzi B. B.), 2 the pupae 

 of which, having escaped from the host, were found at the bottom of 

 the cell. It is quite possible that the premature death and decompo- 

 sition of the parasitized caterpillars had led to that of the others, as 

 well as to that of the Synagris. The parasitism of the Tachina had, 

 therefore, extended its results not only to the hesperid caterpillars, 

 but also to the larva which was to feed on them. This circumstance 

 shows one of the defects in the primitive mode of rearing the larva?. 



Synagris sicheUana Sauss. 



• It is not the same with S. sicheUana Sauss., in which the feeding 

 instinct is perfected, as will be seen presently, in a remarkable man- 

 ner. This species, which builds nests cell by cell, of rude structure, 

 much resembling those of the preceding species, is the most common 

 form of Synagris at Brazzaville. The nests are masses of yellow 

 earth, the surface of which bears the marks of the successive balls of 

 earth which the wasp has joined together to form the cells. The 

 maximum number of cells which I found in a single nest did not 

 exceed eight, and the whole structure was roughly ovoid. The most 

 recent cell is nearly always open, and serves as a shelter for the 

 builder, which very often dies in it. As is usually the case, the ma- 

 terials that serve for the construction of nests are obtained in moist 

 places, mixed with saliva, and carried with very great zeal to the 

 place chosen, which is nearly always under the high roof of houses. 

 The initial cells are higher than broad and roughly conical. Quite 

 often the earth of old nests is used, in which case they are gnawed 

 and demolished all about the orifice ; but I have never observed that 



^lonit. du Seneg. et Dep., Apr. 15, 1879 (communicated by Mr. J. Kimckel d'Herculais). 

 2 1 owe this identification to the kindness of my learned friend Dr. J. Villeneuve. 



