INSECTS 



31 



it is now definitely known that the bite of 

 certain kinds of mosquitoes is really dan- 

 gerous. This is not on account of the 

 actual puncture made by the insect, but 

 due to the presence of the germs of ma- 

 laria, which are introduced into the 

 wound from the infected insect. The 

 only mosqui^es which are definitely 

 known to transmit this malarial parasite 

 to man belong to the genus Anopheles. 

 The malarial parasite thus has two hosts, 

 mosquitoes belonging to the genus Ano- 

 pheles and man. This parasite infests the 



stomach walls of the mosquito, where it 

 rapidly multiplies and becomes mature; 

 then escaping from this locality, accumu- 

 lates in the salivary glands. From this 

 reservoir they are easily transferred to 

 their human host at the time of sucking 

 blood. 



These aquatic insects which we have 

 discussed so briefly are only a few sam- 

 ples from a very large number whose his- 

 tory and habits are full of interest to 

 those who find the study of animal life a 

 fascinating subject. 



INSECT MUSIC. 



The peculiar sounds made by dififerent 

 insects, though usually known as insect 

 music, are probably far from musical in 

 the opinions of those who listen to it with 

 dread. Many superstitious people have 

 firm belief in dire warnings concerning 

 certain calamities which "insect music" 

 portends. 



For instance we are told that the 

 "deathwatch" is a popular name applied 

 to certain beetles which bore into the 

 walls and floors of old houses. They 

 make a ticking sound by standing on their 

 hind legs and knocking their heads 

 against the wood cjuickly and forcibly. 

 Many superstitions have been entertained 

 respecting the noise produced by these 

 msects, which is sometimes imagined to 

 be a warning of death. 



There are many insects, however, 

 which produce sound decidedly musical ; 

 and many such instances have been enum- 

 erated. Everybody is familiar with the 

 music of the katydid. Here it is the male 

 that has the voice. At the base of each 

 wing cover is a thin membraneous plate. 

 He elevates the wing covers, and rubs the 

 two plates together. If you could rub 

 your shoulder blades together you could 

 miitate the operation very nicely. 



Certain grasshoppers make a sound 

 when flying that is like a watchman's rat- 

 tle — clacketty-clack, very rapidly re- 

 peated. There are also some moths and 

 butterflies which have voices. 



The "death's-head" moth makes a noise 

 when frightened that strikingly resembles 

 the crying of a young baby. How it is 



produced is not known, though volumes 

 have been written on the subject. 



The "mourning cloak" butterfly — a 

 dark species with a light border in its 

 wings — makes a cry of alarn: by rubbing 

 its wings together. 



The katydids, crickets, grasshoppers 

 and other musical insects are all exagger- 

 ated in the tropics, assuming giant form. 

 Thus their cries are proportionately 

 louder. 



There is an East Indian cicada which 

 makes a remarkably loud noise. It is 

 called by the natives "dundub," which 

 means drum. From this name comes that 

 of the genus which is known as Diindu- 

 bia. This is one of the few scientific 

 terms from Sanskrit. 



Entomologists have succeeded in re- 

 cording the cries of many insects by the 

 ordinary system of musical notation. But 

 this method does not show the actual 

 pitch, which is usually several octaves 

 above the stafi^. It merely serves to ex- 

 press the musical intervals. 



It IS known with reasonable certainty 

 that many insects have voices so highly 

 pitched that they cannot be heard with 

 the human ear. One evidence of this fact 

 is that some people can distinguish cries 

 of insects which are not audible to others. 

 But even if there are a few notes lost to 

 many of us, there is enough insect music 

 to prove vastly entertaining to those who 

 take interest in the insect world, and the 

 peculiar methods of its inhabitants in 

 comnnmicating with each other. 



