of the Oil Beetle, Meloe, and of the Strepsiptera. 333 



Mr. Pickering argued, at that early period of our knowledge of the habits of 

 Strepsiptera, incontestably proved that the parasite is admitted into the cell of 

 the young bee before the cell is closed by its parent, — a view which has since 

 been completely verified by the observations of Dr. Siebold. Two other spe- 

 cimens of Stylops in Mr. Pickering's bee appear to have been females ; so that 

 both male and female Stylops have been found in the same insect. Some 

 months after this, M. Van Heyden, of Frankfort, stated at the Congress of 

 German Naturalists, held at Bonn in September 1835, that he had met with 

 three species of Xenos (previously shown by him to the Rev. F. W. Hope*), 

 X. Rossii, in Polistes gallica, and two others, one, much smaller than X. Rossii, 

 in a species of Odynerus ; and that he had found the body of the former some- 

 times filled with minute living hexapods, which he also regarded as para- 

 sites, and which resembled Acari, but which had the abdomen articulated. 

 Further, Mr. Pickering in the following April (1836) obtained similar hexa- 

 pods from Stylopsf. Mr. Westwood, who had been directed by Van Heyden 

 himself to the fact of the occurrence of these little objects in Xenos, and who 

 had received from Mr. Pickering some specimens of these acariform bodies 

 obtained from Stylops, and preserved in spirit, afterwards, in the month of June 

 1836, found similar specimens on a stylopized bee, Andrena Gwynana, Kirb., 

 in his own possession. These he also described in the Transactions of the 

 Entomological Society as the parasites of Stylops\ ; but questioned, in a note 

 to his paper, whether these supposed parasites might not be the young of Sty- 

 lops, and the supposed pupae, seen by Rossi, Kirby, Peck, and all subsequent 

 observers, partially projecting from beneath the margin of the abdominal seg- 

 ments of the stylopized insects, be the females ?, as, up to that time, and even 

 to a still more recent period, the female Stylops remained unknown. Mr. 

 W^estwood added, however, "that he should he very fearful of asserting this as 

 the fact.'" Yet such has since been shown by Dr. Siebold to be the truth. 

 This distinguished naturalist, in 1839§, not only found similar hexapods on 



* Trans. Entom. Soc. Lond. vol. i. part 2. (Proceedings, xxxix.) 



t See Mr. Westwood's paper on the Parasites of Stylops, Trans. Ent. Soc. vol. ii. part 3. p. 184, 

 1836-39. 



X Loc. cit. 



§ Ueber Xenos sphecidarum und dessen Schmarotzer, in Beitrage zur Naturgeschichte der Wirbel- 

 losen Thiere, Dantzig, 4to, 1839. 



2x2 



