Insects, etc., Injurious to the Gooseberry. 275 



do. The first fly hatched on the 25th of July. Whether this 

 constituted a second brood or a third brood I cannot say. Cameron 

 says there are two generations during the year. 



The larva? feed 011 the red currant as well as on the gooseberry, 

 and I have one note of its occurrence on the white currant. 



It appears to be known also under the two following names : 

 Nematus catlioraticus, Foer, and N. peleteri, Andre. 



REFERENCES. 

 (1) Cameron, P. ' Monograph of British Phytophagous Hymenoptera,' vol. II., 



p. 66 (1884). 

 <2) Theobald, F. V. Journal S. E. Agri. Coll., No. 11, p. 39 (1902). 



THE GOOSEBERRY EMPHYTUS. 

 (Emphytus grossularice. Kl.) 



This species of sawfly feeds on the gooseberry in England, but 

 is too uncommon to do any harm. 



PARTHENOGENESIS IN GOOSEBERRY SA.WFLIES. 



Parthenogenesis frequently occurs amongst the saw flies. It has 

 been observed in N. ribcsii, X. consobrinus and others by numerous 

 observers. 



Siebold (Beitr. zur Parth. d. Arth., pp. 107) and Kersler (Die 

 Lebens geschichte von Ceutorliynchus sulcicollis and Nematus ventri- 

 cosus. Cassel, 1866) have both observed it. 



"There is not the slightest doubt," says Cameron, "that Nematus 

 ribesii possesses the faculty of laying unfertilised eggs which in- 

 variably yield only males." 



This phenomenon was noticed as long ago as 1820 by Eobeit 

 Thorn (Memoirs Caledonian Hort. Society, IV., pi. 2), but he 

 imagined that male and female larvre copulated. 



The eggs may be laid immediately after the females leave the 

 cocoons and when these unfertilised females have been examined 

 after oviposition no traces of spermatozoa were discovered in the 

 ovaries, while they are easily seen in those that have been fertilised. 

 The first statement made by Cameron was subsequently modified, 

 for in the Appendix to Vol. I. of his Monograph (p. 218) he says that 

 the virgin females of Abia fasciata and N. ribesii yielded males and 

 females. In N. rufa, etc., males and females were also produced, 

 but in Hemichroa rufa, Eriocampa ovata, Nematus appendiculatus 

 and others without exception females only were bred. 



T 2 



