342 ANNUAL REPORT SMITHSONHAN INSTITUTION, 1950 



are used. The antennae, or "feelers," are long slender sensory organs 

 which presumably function as organs of smell and hearing. No 

 conspicuous tympanum or "ear," such as occurs on the side of the 

 first abdominal segment of grasshoppers, or near the front "knees" 

 of most katydids and crickets, is found on the body of a mantid. Near 

 the base of each antenna, however, in the second segment, is located 

 a group of sensory cells comprising Johnston's organ, and this organ 

 is sensitive to vibrations and other stimuli related to sound waves. 



The head is attached to the section of the body immediately behind 

 it (pronotlun) in a way that enables it to be turned very readily to 

 face different directions; scarcely any other insects are able to turn 

 the head as freely. Experimental biologists have found that some 

 mantids have a remarkable tenacity of life with the head removed. 

 Such specimens are known to have lived several days, to have mated, 

 and to have deposited normal egg masses. 



FOOD 



Mantids feed entirely on other animals, in nature consisting almost 

 entirely of insects and closely related creatures caught alive. In- 

 stances of small birds, lizards, or mice being eaten by mantids have 

 been reported, but they are rare and in some cases the result of in- 

 correct observations. A mantid that has been surprised or that 

 comes face to face with an enemy often rears backward, partially 

 spreads the wings in an attempt to frighten the assailant, and adopts 

 a sparring attitude with the forelegs held up in front of the face. 

 More than once a mantid sparring with a sparrow or other small 

 animal has attracted a crowd of people hurrying along a city street. 



Young mantids necessarily capture small insects, such as fruit 

 flies. In the more advanced nymphal stages and when mature, large 

 flies, grasshoppers, caterpillars, butterflies, moths, cockroaches, and 

 other large insects are caught and eaten. The less appetizing portions, 

 such as the wings and legs of grasshoppers, are usually discarded. 

 In the course of feeding, quite edible portions of the prey often be- 

 come detached and fall. Since the mantid is usually on vegetation 

 or other object some distance from the ground, the fallen portions 

 are not retrieved; in fact it is not natural for mantids to pick up 

 fragments of dead food. As an example of the appetite, an adult 

 female of the Carolina mantis has been known to eat 10 adults of 

 the German cockroach, plus a roach egg case, in a period of 2i^ hours, 

 though this is probably far above average food requirements. 



A Chinese mantis that I kept indoors ate stink bugs with no appar- 

 ent concern for the strong-smelling scent gland, and one of my friends 

 told me of another specimen in captivity eating wasps and honey bees. 

 One day it seized a hornet and was apparently stung near the mouth 



