42 SOME SOUTH INDIAN INSECTS, ETC. [CHAP. IV. 



air into a sticky substance which appears to be highly obnoxious 

 to the true Ants which are the Termites' most relentless enemies. 

 In Eutermes, the head of the soldier Termite is provided with a long 

 tube from which can be projected for a distance of two or 

 three inches a very fine jet of liquid which hardens into a thin 

 viscous thread immediately it touches the air. 



In some cases the nauseous liquid oozes out from the glands in 

 such a way as to produce small bubbles, which probably secure a 

 larger surface for the evaporation and rapid diffusion of the smell. 

 Autarches amongst grasshoppers and Heterusia amongst moths are 

 conspicuous examples of this mode of defence. 



Occasionally the liquid discharged is so acrid as to blister the 

 external skin of a vertebrate enemy and the consequences of eating 

 an insect of this kind would doubtless be very serious. The best- 

 known insects of this class arc the Blister-beetles, many of which 

 arc extremely common in India and are conspicuously coloured red- 

 and-black, blue, green, yellow, etc. In these beetles the glands are 

 situated in the legs, the beetle when touched exuding a yellowish 

 oily liquid which is capable of raising a large blister on contact 

 with the tender human skin. Some of these beetles contain quite 

 a considerable percentage of Cantharidin. 



The shape or structure of an insect may be such as to render it 

 distasteful and secure it from hostile attack. The thickly-chitinized, 

 almost armour-plated, integuments of some beetles and the 

 possession of sharp spines in many beetles, bugs, grass-hoppers, 

 etc., may be quoted as familiar examples. The two cases differ 

 somewhat as exhibiting defence against different classes of enemy, 

 since mere hardness (as of some weevils) would not avail against 

 an enemy, such as a bird, large enough to swallow the weevil 

 whole and grind it down in the gizzard or slowly dissolve its 

 interior by digestive fluids gaining access by the joints and other 

 apertures, whilst, on the other hand, such defences as sharp spines 

 would help to protect an insect against large enemies but not 

 necessarily against smaller ones. 



Hairy caterpillars, in which the hairs possess more or less 

 irritant qualities, arc sufficiently familiar in Southern India, where 

 the general terms "Kumbli-hula " or " Kumbli-puchi " are freely 

 and loosely applied to many very different kinds. In many of 

 such caterpillars the whole body is covered with long hairs which 

 are often rather loosely attached and barbed at the tip, so that they 

 readily pierce the skin and become detached or break off, leaving 

 the barbed tips which act as a mechanical irritant in the skin. 

 Such hairs may also enable the caterpillar to escape by slipping 

 out of the grasp of a captor or by keeping smaller insects (e.g., ants) 



