9. CHELOSTOMA. 165 



to the bees' requirements : on one occasion I found numbers occu- 

 pying the straws of a thatched outhouse. Chelostoma is subject to 

 the attacks of several parasitic insects ; Ghrysis cyanea and C. ignita 

 have both been bred from its nests, also Foenus assectator, an insect 

 frequently seen where the burrows of Chelostoma are found. Mr. 

 Marsham, in the ' Transactions of the Linnean Society/ volume iii., 

 has given an account of Pimpla manifestator introducing its eggs 

 into the nests of this bee ; but it is not very clearly shown that the 

 larva of Chelostoma was the object of its attack. I am inclined to 

 suspect it was the larva either of Melandrya caraboides or that of 

 Clytus arietis; both these insects are commonly to be seen about 

 the burrows of Chelostoma, inserting the apical segment of their ab- 

 domen into them, the burrows forming a suitable situation for their 

 eggs, and the larvae being wood-eaters. Mr. Kirby records the 

 fact of his friend Mr. Trimmer obtaining Ichneumon femorator from 

 the nest of Chelostoma. 



The males of this genus usually pass the night in flowers, in which 

 they curl up their bodies and take their repose ; but at other times 

 they pass the night in a position that would appear to be ill suited 

 for repose. I have observed them attaching themselves to blades of 

 grass by seizing hold with their mandibles and suspending them- 

 selves in a horizontal position, with their hind legs stretched out in 

 a line with their bodies. A number of males thus suspended were 

 found on a dead branch of hawthorn ; they were killed by chloro- 

 form, and remained thus attached after death, so that the branch 

 and bees could be exhibited at a meeting of the Entomological 

 Society of London. Other species of Hymenoptera (for instance, some 

 Polistidae) attach themselves in a similar manner. Other insects curl 

 their bodies round straws, twigs, or blades of grass: this is the 

 habit of several species of Chrysididae, of Stilbum and Hedychrum, 

 and of Elampus panzeri. 



1. Chelostoma florisonme. 



C. atrum, elongatum, glabriuseulum ; mandibulis prominentibus, 

 intus fulvo-barbatis ; abdominis segmentis marginibus albis. Mas 

 cinereo villosus ; abdomine incurvo, ventre basi cornuta, ano 

 bidentato. 



Chelostoma florisonme, Curtis, Brit. Ent. xiv. tab. 628 c? . 



Eversm. Bull. Soc. Moscou, xv. 74. 



Smith, Zool. iv. 1445; Bees Great Brit. 189 S 2- 

 Apis florisomnis, Linn. Syst. Nat. i. 954 <j , et Cab. Mus. Linn. Soc. 



Scop. Ent. Cam. 299, fig. 796. 



Eabr. Syst. Ent 387. 



Kirby, Mon. Apum Angl. ii. 253. 

 Hylasus florisomnis, Eabr. Syst. Piez. 319 £ . 



Panz. Faun. Germ. 46. 13. 

 Megachile florisomnis, Spin. Ins. Ligur. i. 134. 

 Apis maxillosa, Linn, Syst. Nat. 954 § , et Cab. Mus. Linn. Soc. § , 



Kirby, Mon. Apum Angl. ii. 251. 

 Hylaeus maxillosus, Eabr. Ent. Syst. ii. 303. 



Panz. Faun. Germ. 53. 17. 



