PALATABILITY OF SOME BRITISH INSECTS. 855 



I then again ottered the Bombus to the first Haugnest. He 

 took it and flicked it away, and immediately afterwards refused 

 to touch the Volucella. 



Next day I offered the first Hangnest a Bombus again ; lie took 

 it from me three times, and flicked it away without attempting 

 to eat it, but immediately afterwards took Chilosia illustrata and 

 ate it. 



The second Hangnest took a dead Bombus, and flicked it away, 

 and then ate Chilosia illustrata, but refused immediately after- 

 wards to touch a live Bombus hortorum. 



Offered Bombus hortorum to North American Cat-bird, which 

 came up to me on seeing other birds being fed. He pecked it 

 several times, but flicked it away and gave it up. During the 

 next quarter of an hour I could not induce him to touch either 

 Volucella bombylans or Chilosia illustrata. 



I then offered the Bombus on the forceps to a Sulphury Tyrant. 

 He pecked and flicked it away several times, then left it, and 

 refused it when offered again. I then offered him the Volucella 

 bombylans both in the forceps and by throwing it to him on the 

 ground, but he would not touch it. After a little hesitation, 

 however, he took an Echinomyia ferox from the forceps and ate 

 it, and then took and ate Chilosia illustrata. I then offered him 

 Bombus hortorum again, and he took it but soon rejected it, and 

 immediately afterwards refused to touch Volucella bombylans. 



One Bombus hortorum offered to a Shama, which pecked it once 

 or twice, and flicked it away each time. He then refused to touch 

 the specimen of Volucella bombylans. 



Tried the experiment with another Shama, which behaved in 

 exactly the same way towards the bee, and would not afterwards 

 touch the Volucella bombylans. 



One Bombus hortorum offered to Silver Pheasant was taken at 

 once, but left after some pecking and tasting. Then without 

 hesitation he took Chilosia illustrata from the forceps and ate it ; 

 and promptly tried the Bombus again as it lay on the ground, 

 but would not eat it. Immediately afterwards he eagerly ate an 

 Ocypus olens and three specimens of Pterostichus (see pp. 837-838). 



I made one Volucella bombylans do duty for all the experiments 

 described above and had it intact at the end. It was not pecked 

 by any of the birds, presumably because I never offered it to one 

 until he had tried Bombus hortorum a sufficient number of times 

 to reject it as unpalatable ; and there is no doubt in my opinion 

 that they did not distinguish between the bee and the fly. 

 Although Chilosia illustrata is also very like Bombus, the difference 

 in size is well marked. I suspect that in this circumstance lies 

 the explanation of the birds not confusing this species of fly with 

 the bee. They could judge the difference in size quite easily, 

 because the insects were held at the same distance from them. 



[47] 



