46 



THE ENTOMOLOGIST. 



females, and I then stood for a few seconds watching where the 

 remainder were settling. Meanwhile the two males in my net 

 were screeching vigorouslj^ and I noticed two cicadas fly round 

 successively and settle momentarily on the net. These I marked 

 down, and on capturing them found them to be both females. If 

 this be taken as an instance of the female flying direct to the call 

 of the male, it is the only one that has come under my notice. 

 Cicadas, however, do not seem to indulge much in flight, and con- 

 sidering the numbers there must be about, I have seen very few 

 on the wing, except when they have been actually disturbed. 

 Their sluggishness may perhaps be accounted for by the fact 

 that these insects are perfectly defenceless, their only protection 

 being their excellently protective colouring ; and therefore their 

 greatest safety lies in sitting still. This is a most important 

 fact, which has been quite overlooked by Mr. Arkle in his 

 supposititious case of Melanippe Jiuctuata remaining undisturbed 

 by a military band, and one which often renders it very difficult to 

 decide the true effect of sound, &c., on an insect. The fact that 

 the moth was not disturbed by the music is no more a proof of 

 its deafness than the fact that it did not fly away at the sight of 

 the approaching stick (but waited to be touched) is a proof that 

 it could not see. The great majority of unarmed insects, which 

 are well adapted to their surroundings, sit fairly close. This is 

 the case with the cicadas ; several species allowing the branch on 

 which they are sitting to be roughly shaken, or even struck 

 sharply with a stick within a few inches of themselves, without 

 moving ; and yet this is no proof that they have no sense of 

 touch. For such insects immobility is their safest course, up to 

 a certain point. 



I have so far dealt only with insects which possess a distinct 

 sound-producing apparatus. I will therefore now take an example 

 from those which are without such adjuncts. While strolling in 

 the bush round my camp after dark with a lantern, in search of 

 those giant Carabidse, Tefflus and Anthia, I have often been 

 attracted by a sharp pattering sound among the heaps of dead 

 leaves. On inspection this proves to emanate from a small 

 blackish termite. A closer investigation shows that the sound is 

 produced by the large-headed soldiers only, which are walking 

 about among the leaves in front of the workers, while the latter 

 are busy building their little mud tunnels. The method in 

 which they produce the sound is by raising themselves on their 

 legs, and then, with a very rapid motion, striking the leaf two or 

 three times with their heads. Now the naturalist who is worthy 

 of the name requires some reasonable explanation for all such 

 facts he may observe. Why do the soldiers stand in front, often 

 exposing themselves on the tops of the leaves ? and why do they 

 strike their heads thus on being approached ? Obviously they 

 are there to guard the defenceless workers with their well* 

 developed jaws, and to give warning, by rapping, of impending 



