THE YOUNG NATUEALIST. 



89 



hop off immediately to the traps, and cautiously turning them over, meet 

 with considerable and well deserved success. 



Of the ultimate fate of the three rooks we kept, it may be interesting to 

 say something. One was killed in a fight as I have described, a second was 

 given away to a friend, and the third, a fine handsome fellow, came to grief 

 whilst trespassing in some one's garden. We afterwards heard that in his 

 search for food he had uprooted nearly four hundred hopeful young cabbage 

 plants. Prom our experience, however, we were enable to pronounce the 

 rook as an amusing pet, far more interesting than the jackdaw and many 

 other birds in captivity. 



APANTELES GLOMERATUS AND MESOCHORUS 



ACICULATUS. 



By G. C. BIGNELL, Stonehouse, Plymouth. 



" In September last the enclosed flies were bred from the cocoons sent herewith, 

 they came out of a black and yellow caterpillar on cabbage, which I suppose 

 was Pieris brassicce, I have set them as well as I could. They do not look 

 alike. Are they males and females of the same species ?" — J. Kosewear. 



The flies you have sent are two species, viz., Apanteles glomeratus, and 

 Mesochorus aciculatus. The former is a parasite of Pieris Brassicce and 

 rap<z t and the maker of these small cocoons. These cocoons, like minature 

 silk-worm cocoons, may often be found on wales and fences of cabbage gardens 

 beside their victim, and numbering from forty to sixty from one caterpillar. 



On the 14th September, 1883, I obtained a large caterpillar of P. brassicce, 

 and being such a fine specimen, I thought it would produce an extra large 

 insect, instead of which, a few days after I brought it home, there issued from 

 it, the extraordinary number of 142 larvae of A. glomeratus ; and to show 

 how they vary in number, on the 21st September, a week after bringing 

 home the large caterpillar, I secured from another cabbage garden some very 

 small larvse of P. rapce, not half-an-inch in length, and three of these were 

 infested, but only had one larvse in each ; they left their respective victims 

 before they (the victims) were half grown; these produced flies almost 

 twice as large as those that came out of the brassicce larva mentioned. 



Those from rapce did not appear as flies until the following June, whereas 

 many from the brassicce emerged in October, and the remainder in May and 

 June following, 



Mesochorus aciculatus is a hyper-parasite, i.e. a parasite on A. glomeratus, 

 consequently they would emerge from the cocoons made by the victim, and 



