INSECTS 



is no admixture of the blackened contents of the burrows. 

 It is unlikely, too, that they base their judgments on a 

 sense of temperature, because their acts are not regulated 

 by the nature of the season, which, if early or late, would 

 fool them in their calculations. 



Early in the spring, before the proper emergence season, 

 cicada nymphs are often found beneath logs and stones. 

 This is to be expected, for, to the ascending insect, some- 

 thing impenetrable has blocked the way, and there is 

 nothing to tell it that it has already reached the level of 

 the surface. 

 A more curious thing, often observed in some localities, 



is that the insects some- 

 times continue their 

 chambers up above the 

 surface of the ground 

 within closed turrets of 

 mud from two to several 

 inches in height (Fig. 

 117). At certain places 

 these cicada "huts" have 

 been reported as occur- 

 ring in great numbers; 

 and it has been supposed 

 that they may be built 

 wherever there is some- 

 thing about the nature of 

 the soil that the insects 

 do not like, the earth 

 being perhaps too damp, 

 for they are frequently 

 found where the ground 

 is unusually wet. On the other hand, the turrets have 

 been observed in dry situations as well, and towers and 

 holes flush with the surface frequently occur intermingled. 

 The writer has had no opportunity of studying the cicada 

 turrets, but a most interesting description of them is given 



[ 19*1 



Fig. 117. Earthen turrets sometimes, 

 erected by the nymphs of the periodical 

 cicada as continuations from their under- 

 ground chambers. One cut open showing 

 the tubular cavity within. (From photo- 

 graph by Marlatt) 



