NOTES ON HYMENOPTEKA. 99 



valescent Home, as were also Saijyga jjunctata, Osmia 

 xanthomelana and O. aurulenta; the latter were observed 

 entering their nests, the burrows being made in a loamy bank 

 in a chalk-pit ; the bees were so numerous that at least twenty 

 could be captured hy one sweep of a net, I never saw this 

 species in such abundance before 5 this occurred in the last 

 week in June. 



On the first of July the rare Osmia leiicomelana was 

 taken at Weybridge, and also three or four specimens of 

 Elavipus Panzeri; this is one of the rarest species of Chry- 

 siclid(By but has been several times taken by myself and others 

 at this locality. 



When at Sidmouth, in the month of August, I collected 

 some hundreds of the oak-galls of Cynips lignicolaj taking 

 care to observe that none of the insects had previously es- 

 caped; on my arrival, at the beginning of the month, I 

 observed that the galls were soft and pulpy ; from time to 

 time I watched them on the oaks and deferred gathering them 

 until they were more matured; at the end of the month, 

 having gathered them, I found the flies beginning to escape 

 from the galls which were kept in nets; not a single male 

 has been obtained out of several hundreds of galls. I have 

 now bred, during the last ten years, many thousands of 

 Cynips Ugnicolaj and I believe that if this species ever 

 evolves a male, it must be at intervals of years. Mr. Walsh 

 obtained males from the American gall-fly, Cynips spongi- 

 fica; and he tells us, that '* out of thousands of galls collected 

 before the month of June, that about the fore-part, or by 

 the middle of June, both male and female gall-flies eat their 

 way out of a certain number, about a fourth part. The 

 remaining larvs lay dormant for more than two months, 

 when they changed into the pupa state, and subsequently 

 about October eat their way out in the form of gall-flies; 



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