Entomological Society. • 2809 



Habitat in Epiro, quercibus prope Sinum Ambracicum. 



The Hylecthrus quercus was obtained from this species, the abdomen exhibiting 

 irregular rufous patches in some specimens parasitically affected. 



Having reared two new species from the bodies of bees of the genus Hylaeus, 

 Mr. Saunders availed himself of the opportunity to offer some remarks on these para- 

 sites, and certain particulars which had come under his notice. The first species he 

 obtained from oak-galls, which he had placed in a box and forgotten till some months 

 afterwards, when he found — on some Hylaei which had been produced and died — 

 abdominal protuberances caused by the presence of Strepsiptera, still in their pupa 

 envelopes, having perished in situ, after attaining the imago state. The following 

 year he could find no more Hylaei in oak-galls ; but knowing that the larvae of these 

 bees nidificated in briars, he collected some briar-snags, and on the 28th of May se- 

 lected from their occupants five already-formed pupae, the remainder being still in 

 the larva state : of these, three completed their transformations within two days, when 

 he saw the usual parasitic phenomena, not previously apparent ; and the next morn- 

 ing, on placing them in the sun, two winged parasites — smaller than those previously 

 obtained from the Hylaeus of the gall — speedily came forth. The remaining selected 

 pupae never attained the imago state. From the ample stock of larvae and briars re- 

 maining he expected to have reared numbers of the parasite, but in this he was mis- 

 taken, the gestation of the parasite apparently rendering the Hylaeus precocious, for 

 none of the bees that came out late produced any parasite : yet although the bees 

 which produced parasites have always been observed to assume the imago state before 

 others not parasitically affected, their appearance has varied according to the season, 

 from the middle of May to the middle of June. The parasitic pupae have almost 

 invariably shown themselves contemporaneously with the imago bee (never sooner), 

 whose contortions in wriggling itself out of the pupa-envelope may not impossibly 

 assist the parasite in driving the prominent dentate apex of the male pupa, or the 

 subcuspidate cephalothorax of the female, through the abdominal folds ; though it 

 may indeed also be assumed that this is accomplished, as Dr. Siebold seems to think, 

 by the larva. Among another lot of larvae and pupae of Hylaei, set apart and care- 

 fully watched, no symptom of Strepsipterous distension could be discovered in either 

 of those stages : however, he at length observed in two pupae, on the right side only, 

 the dark markings usually preceding the development of the bee, and found, on the 

 pupa-pellicles being discarded the next day, Strepsipterous parasites ready to burst 

 forth had become conspicuously prominent on the opposite side. So long as the 

 Hylaei remained in the dark, the parasites made no attempt to leave their pupae, as 

 an incentive to which light appears essential ; for in one instance, some Hylaei having 

 become mature in a closed box, where they remained some time, none of the parasitic 

 skull-caps were removed ; so that it seems that unless aroused, after assuming the 

 imago state, by the stimulus of light, they die without emerging from the pupa-case. 

 Adverting to the observations of Mr. Westwood and Dr. Siebold on the hexapod 

 larvae of the Strepsiptera, and those of Mr. Newport on the whole series of changes 

 which take place in the ovum within the body of the female Stylops, herself contained 

 within that of the bee, he said that they did not affect the origin of these ova, nor did 

 it appear that their presence had been detected in any larviform Strepsipterous insect 

 obtained from a bee not taken at large, whereby the possibility of extraneous oviposi- 

 tion would be absolutely negatived : but the circumstantial evidence affecting the 



