PRAYING MANTIDS — GURNET 345 



first-stage nymph of Ilymenopus coronatus resembles a bug of the 

 family Eeduviidae, which probably can inflict a severe bite in addition 

 to tasting bad. In India certain mantids resemble ants, while in 

 Indo-China a common type of arboreal tiger beetle (Cicindelidae) is 

 the model for a mantid {Tricondylomimus cooniani Chopard). The 

 subject of protective mimicry is a highly controversial one, and for 

 the present purpose it is sufiicient to invite attention to these striking 

 resemblances on the part of a few tropical species and to suggest the 

 stimulating interest that might come from investigations by people 

 situated where such species occur. 



GROWTH AND MOLTING 



The eggs of mantids hatch in spring and early in summer, unless 

 they are induced to hatch sooner by a warm climate or by being brought 

 indoors. In the northeastern United States mantids usually hatch 

 late in May and in June, and they customarily mature in 2 to 3 months, 

 the adults occurring from late in August or in September until frost 

 kills them or they die of other natural causes. In captivity some 

 mantids have lived as long as 4 to 5 months after reaching maturity, 

 but the average is much less. 



Newly hatclied young, called nymphs, resemble the adults except 

 that they are small and delicate and have no wings. Like other Or- 

 thoptera and the more primitive insects in general, mantids have no 

 grub or caterpillar stage. These stages, technically referred to as 

 larvae, occur only among higher insects, beginning with Neuroptera 

 (hellgrammites, ant lions, aphis lions) and including Diptera (mag- 

 gots of various kinds), Lepidoptera (caterpillars'), Coleoptera (beetle 

 grubs) , and Hymenoptera (larvae of bees, wasps, and ants) . 



The &gg cases, technically known as oothecae, of most mantids have 

 a hatching area on the surface of the case that is opposite the side that 

 is attached to a support. Chambers or passageways lead from this 

 hatching area directly to the eggs. The emerging nymphs wriggle, 

 head foremost, up these passageways to the surface and there hang 

 head down while they prepare to get the use of their legs. At 7 : 15 

 one morning early in June I noticed that about 20 nymphs were be- 

 ginning to emerge from one of my egg cases of the Chinese mantis. 

 They were a rich yellow color, with dark eye spots and with the legs 

 and antennae limp and folded back beside the body. Within half an 

 hour 100 or more nymphs were out, and the whole wriggling mass was 

 hanging from the egg case. Some had their legs free and were al- 

 read}'^ crawling, though still yellow in color. By 9 o'clock all were 

 free, nearly all had turned to a neutral gray color, and they were ready 

 to be released on shrubs in my garden. A cluster of membranous 

 shreds, of indefinite shape, remained hanging from the hatching area 

 of the egg case. 



