ii6 



AFRICAN MIMETIC BUTTERFLIES 



wrapped hers up and carried it off. She turned it over several times, bit it here and there, 

 and then left it, ultimately throwing it away. 



21. A. serena-buxtoni was eaten by three spiders. It is to be noted that thii species 

 exudes a bitter yellow juice when captured, and thus may have lost much of its nauseous 

 qualities and would be less distasteful than if caught by the spiders direct. 



The author draws very interesting conclusions from the experiments. He points out 

 that invertebrate enemies such as spiders and mantises do not appear to appreciate warning 

 colours, and that herein, no doubt, lies the great advantage to the victims, of the great 

 tenacity of life in distasteful insects. Inedible qualities alone would not protect an insect 

 against experimental tasting by enemies which did not recognize its aposematic coloration, 

 whilst tenacity of life in edible forms would be of no assistance, since they would very seldom 

 escape after being caught and tasted. The great tenacity of life possessed by distasteful 

 butterflies such as Acraeinae, and Danainae has been frequently noticed by collectors, as 

 instanced by Trimen's remarks already quoted. The usual nip under the thorax does not 

 kill them, whilst the wings may often be bent almost double without any apparent injury, 

 so supple are the nervures and membranes. 



Marshall's experiments with lizards and frogs gave but little result, as the lizards obtained 

 did not appear to be species which habitually fed on butterflies, and also they did not thrive 

 in captivity. That lizards do, however, prey on butterflies is shown by the fact that he 

 frequently observed these animals stalking butterflies at rest ' with much astuteness and 

 in another passage, speaking of Precis sesamus f. natalensis, he says, ' It is wevy wary and 

 difficult of approach, being kept on the alert by its enemies the lizards. I have often watched 

 these little reptiles stalking both natalensis and pelasgis round the stones, and have seen 

 them capture and eat both species.' 



With birds more success was obtained. A young kestrel, after tasting an Acraea caldarena, 

 threw it away and would eat neither it nor other Acraeas which were offered, though it ate 

 with relish Precis pelasgis, Jimonia cehrene, Precis sesamus, and Atella phalantha. Another 

 of these birds, though of a different species, refused A. halali, A. anemosa, and L. chrysippus, 

 shortly afterwards eating B. ilithya and Terias brigitta. Under stress of hunger this bird 

 ate part of an .4. caldarena, but threw away the rest. On another occasion the same bird, 

 after eating some other butterflies, was offered D. chrysippus. After one or two pecks it 

 was thrown away. The bird then ate H. daedalus and tasted A. caldarena, which it threw 

 away after eating a small part ; P. sesamus, J. cebrene, and B. ilithya were then eaten with 

 relish. After being starved for twenty-four hours, this bird ate ten butterflies and several 

 grasshoppers. Amongst the former were A. caldarena, A. rahira, A. axina, and A. halali. 

 OneD. chrysippus was partly eaten, and one was refused. These tests afford good evidence 

 of the distastefulness of Acraeas, and also point to the conclusion that D. chrysippus is, to 

 birds at any rate, still more objectionable. 



A tame ground horn-bill {Bucorax caffer) ate three A. serena, one P. lyaeus, and one 

 H. misippus, but immediately dropped D. chrysippus after crushing the thorax, and shortly 

 afterwards treated a second example of this butterfly in the same manner. On other occa- 

 sions this bird ate eighteen butterflies, including five Acraeas, and again six butterflies 

 including four Acraeas. Acraeas were apparently not particularly objectionable to this bird, 

 though it is significant that it would not eat D. chrysippus, the conclusion being that the 

 latter was very much more distasteful, whilst it will be remembered that one of the mantises 

 did not appear to make any distinction. 



A verj' young female mongoose {Herpestes galera) was experimented upon with insect 



